MCI 08.61
MARINE CORPS INSTITUTE
BASIC FORWARD
OBSERVATION
PROCEDURES
08.61 6 Dec 96
MCI 08.61 BASIC FORWARD OBSERVATION PROCEDURES
1. Purpose. MCI course 08.61, Basic Forward Observation Procedures, has been published to provide instruction for all Marines to properly call for and adjust indirect fire support.
2. Scope. MCI 08.61 introduces Marines to the types of indirect fire support available to the operating forces, the different means of targeting, and target designations. Instruction is given in the three methods used to locate targets of opportunity: grid coordinates, polar plot, and shift from a known point. In addition, the course emphasizes conduct of fire missions and
communication procedures utilized by fire support units.
3. Applicability. This course is intended for instructional purposes only. It is designed for use by all Marines.
4. Recommendations. Comments and recommendations on the contents of the course text are invited and will aid in subsequent course revisions. Please complete the course evaluation questionnaire located at the end of the text and return it to:
Director (CDD# 3) Marine Corps Institute Washington Navy Yard 912 Poor Street SE
Washington, DC 20391-5680
R. A. CHRISTIE
UNITED STATES MARINE CORPS
MARINE CORPS INSTITUTE 912 POOR STREET SE WASHINGTON, DC 20391-5680
BASIC FORWARD OBSERVATION PROCEDURES
CONTENTS
Page Contents . . . i Student Information . . . iii Study Guide . . . v Study Unit 1 Indirect Fire Support Characteristics
Lesson 1 Fire Support Characteristics . . . 1-1 Exercise . . . 1-4 Lesson 2 Fire Support Organization and Targeting . . . 1-5 Exercise . . . 1-8 Lesson 3 Artillery Ammunition . . . 1-10
Exercise . . . 1-14 Study Unit 2 Target Location
Lesson 1 Map/Terrain Association . . . 2-1 Exercise . . . 2-4 Lesson 2 Determining Direction (Azimuth) to the Target . . . 2-5 Exercise . . . 2-10 Lesson 3 Determining Distance . . . 2-12 Exercise . . . 2-17 Lesson 4 Methods of Target Location . . . 2-18 Exercise . . . 2-21 Study Unit 3 Conducting Fire Missions
Lesson 1 Fire Missions . . . 3-1 Exercise . . . 3-3 Lesson 2 Artillery Communication . . . 3-5 Exercise . . . 3-14
CONTENTS--cont'd
Page
Lesson 3 Spotting and Corrections . . . 3-15 Exercise . . . 3-22 Lesson 4 Adjustment and Fire for Effect . . . 3-24 Exercise . . . 3-30 Review Lesson . . . R-1
STUDENT INFORMATION TITLE &
NUMBER: BASIC FORWARD OBSERVATION PROCEDURES MCI 08.61
STUDY
HOURS: 12
COURSE
MATERIALS: Text REVIEW
AGENCY: COMMANDING OFFICER
U.S. Army Field Artillery School
(Attn: Marine Corps Admin Detachment) Fort Sill, OK 73503
RRC: 4 Reserve Retirement Credits
ACE: To be reviewed by the American Council on Education in 1996
ASSISTANCE: For administrative assistance, have your training officer or NCO use the Unit Activity Report (UAR) or MCI Hotline: DSN 288-4175 or Commercial (202) 433-4175.
For assistance concerning course content matters, call the instructor at DSN 288-2290/0208/0210, ext 285 or commercial (202) 433-0208/0210/2290, ext 285.
STUDY GUIDE
Congratulations on your enrollment in a distance training course from the Occupational Specialty Department of the Marine Corps Institute (MCI). Since 1920, the Marine Corps Institute has been helping tens of thousands of hard-charging Marines, like you, improve their technical job performance skills through distance training. By enrolling in this course, you have shown a desire to improve the skills you have and master new skills to enhance your job performance.
The distance training course you have chosen, MCI course 08.61, Basic Forward Observation Proedures, introduces Marines to the types of indirect fire support available to the Fleet Marine Force (FMF), the different means of targeting, and target designations. Instruction is given in the three methods used to locate targets of opportunity: grid coordinates, polar plot, and shift from a known point. In addition, it emphasizes on the conduct of fire missions and communications with artillery units.
Because you have chosen to learn at a distance by enrolling in this MCI course, your professional traits are evident and we know
YOU ARE PROPERLY MOTIVATED. You made a positive decision to get
training on your own. Self-motivation is perhaps the most important force in learning or achieving anything. Doing whatever is necessary to learn is MOTIVATION. You have it!
YOU SEEK TO IMPROVE YOURSELF. You enrolled to improve those skills
you already possess and learn new skills. When you improve yourself, you improve the Corps!
YOU HAVE THE INITIATIVE TO ACT. By acting on your own, you have
shown you are a self-starter, willing to reach out for opportunities to learn and grow.
YOU ACCEPT CHALLENGES. You have self-confidence and believe in your
ability to acquire knowledge and skills. You have the self-confidence to set goals and the ability to achieve them, enabling you to meet every challenge.
YOU ARE ABLE TO SET AND ACCOMPLISH PRACTICAL GOALS. You
are willing to commit time, effort, and the resources necessary to set and accomplish your goals. These professional traits will help you successfully complete this distance training course.
STUDY GUIDE, continued
Before you actually begin this course of study, read the Student Information page. If you find any course materials missing, notify your training officer or training NCO. If you have all the required materials, you are ready to begin.
To begin your course of study, familiarize yourself with the structure of the course text. One way to do this is to read the Table of Contents. Notice the Table of Contents covers specific areas of study and the order in which they are presented. You will find the text divided into several study units and a review lesson. Each study unit is comprised of two or more lessons, lesson or unit exercises, exercise solutions and references.
BEGINNING YOUR
COURSE
Leaf through the text and look at the figures and tables. Read a few lesson exercise items (questions) to get an idea of the type of items in the course. If the course has additional study aids, such as a handbook or a plotting board, familiarize yourself with them.
LEAFING THROUGH THE TEXT
Turn to the first page of Study Unit 1. On this page, you will find an introduction to the study unit and generally the first study unit lesson. Study unit lessons contain learning objectives, lesson text, and exercises.
THE FIRST STUDY UNIT
Learning objectives describe in concise terms what the successful learner, you, will be able to do as a result mastering the content of the lesson text. Read the objectives for each lesson and then read the lesson text. As you read the lesson text, make notes on the points you feel are important.
READING THE LEARNING OBJECTIVES
To determine your mastery of the learning objectives and text, complete the exercises developed for you. Exercises may be contained in a lesson, at the end of a lesson, or at the end of a
COMPLETING THE
STUDY GUIDE, continued
If you have problems with the text or exercise items that you cannot resolve, ask your training officer or training NCO for assistance. If they cannot help you, request assistance from your MCI distance training instructor by completing the Content Assistance Request Form located at the back of the course.
SEEKING ASSISTANCE
To prepare for your final exam, you must review what you learned in the course. The following suggestions will help make the review interesting and challenging.
CHALLENGE YOURSELF. Try to recall the entire learning sequence without referring to the text. Can you do it? Now look back at the text to see if you have left anything out. This review should be interesting. Undoubtedly, you'll find you were not able to recall everything. But with a little effort you'll be able to recall a great deal of the information.
USE UNUSED MINUTES. Use your spare moments to review. Read your notes or a part of a study unit, rework exercise items, review again; you can do many of these things during the unused minutes of every day.
APPLY WHAT YOU HAVE LEARNED. It is always best to use the skill or knowledge you've learned as soon as possible. If it isn't possible to actually use the skill or knowledge, at least try to imagine a situation in which you would apply this learning. For example, make up and solve your own problems. Or, better still, make up and solve problems that use most of the elements of a study unit.
PREPARING FOR THE FINAL EXAM
When you have finished all the study units, complete the review lesson exam located at the end of the course text. Try to complete the review lesson exam without referring to the text. For those items you are unsure of, restudy the text. When you have finished the review lesson exam and are satisfied with your responses, check your responses against the answer key provided with your course materials.
THE REVIEW LESSON EXAM
When you have completed your study of the course material and are confident with the results attained on your review lesson(s) take the sealed envelope marked "FINAL EXAM" to your unit training NCO or training officer. Your training NCO or officer will administer the final exam and return the exam and answer sheet to MCI for grading. Prior to taking your final exam, read the
directions on the NEW (generic DP-37) answer sheet carefully and complete all requested information.
TACKLING THE
FINAL EXAM
MAKE REVIEWS FUN AND BENEFICIAL. Reviews are good habits that enhance learning. They don't have to be long and tedious. In fact, some learners find short reviews conducted more often prove more beneficial.
USE THE "SHAKEDOWN CRUISE" TECHNIQUE. Ask another Marine to lend a hand by asking you questions about the course. Choose a particular study unit and let your buddy "fire away."
STUDY GUIDE, continued
The sooner you complete your course, the sooner you can better yourself by applying what you've learned! HOWEVER--you do have 12 months from the date of enrollment to complete this course. In addition, you may be granted one 6-month extension if approved by your Commanding Officer. If you need an extension, please complete the Student Request/Inquiry form (MCI-R11) located at the back of the course, and deliver it to your training officer or training NCO.
COMPLETING YOUR
COURSE
As a graduate of this distance training course and as a dedicated Marine, your job performance skills will improve, benefiting you,
STUDY UNIT 1
INDIRECT FIRE SUPPORT CHARACTERISTICS
Introduction. To effectively use indirect fire support assets, you should have a basic overview of their characteristics, fire support organization, and artillery ammunition.
Before any Marine employs a weapon, he should have a good understanding of its operation so that he may use it safely and more effectively. This rule is true for your use of indirect fire support means as well.
Lesson 1. FIRE SUPPORT CHARACTERISTICS
LEARNING OBJECTIVES
1. Select the three types of indirect fire support available to FMF Units. 2. Identify the three indirect fire support assets with their characteristics.
1101. Types of Indirect Fire Support
The three types of indirect fire support available to you are mortars, naval gunfire, and howitzers. Each of these three types of support has its own characteristics and limitations. You may not always have the choice of all three assets, but you should know which of them you can select when they are available. The major differences among the three are their sizes, trajectories, and firing capabilities.
1102. Characteristics of Indirect Fire Support Weapons
a. Mortars.
(1) Size. Mortars, which are organic to the Marine Corps Infantry Battalion, are
categorized as light artillery. There are two types: the 60mm mortar (fig 1-1), which is organic to the weapons platoon of each company, and the 81mm mortar (fig 1-2), which is organic to the weapons company of each battalion. Because of their size, these mortars are best suited to attack personnel. They have very limited usefulness against material targets and require large amounts of ammunition to attack large personnel targets.
Figure 1-1. 60mm mortar. Figure 1-2. 81mm mortar. (2) Trajectory. A mortar trajectory is characterized by low muzzle velocity and a high
trajectory similar to a good punt in football. This means that mortars can be effective against targets which are entrenched or situated on a reverse slope and inaccessible to direct fire. It also means that mortar adjustments are not overly distorted by uneven terrain.
(3) Firing capabilities. Mortars have a high rate of fire. They can fire a sustained rate of up to 20 rounds per minute, depending upon the type of round and mortar being used. They also have a short-range and must keep close to the forward line of troops
(FLOT) to maintain fire support. Mortar platoons act as independent firing units and do not mass fires (bring several units to bear on one target simultaneously). Because of resupply problems, the Marines in mortar sections must very often carry their weapons and their ammunition on their backs. Therefore, mortar ammunition is limited and should be used sparingly.
b. Naval surface fire support.
(1) Size. Naval gunfire currently uses the 5-inch/54 caliber gun mount (caliber on naval guns is determined by dividing the length of the weapon by the diameter of its bore). Five-inch naval gunfire shells are comparable to 155mm rounds and are classified as
(3) Firing capabilities. Naval gunfire ships carry 600 rounds of ammunition per gun, which can be quickly used with naval gunfires' high rate of fire, 20 rounds per minute (RPM), in a high intensity environment.
c. Howitzers (Figures 1-3 and 1-4)
(1) Size. The current Marine Corps inventory has 105mm and 155mm howitzers. The 105mm is classified as light artillery, the 155mm as medium artillery. The vast majority of artillery support is provided by the 155mm.
(2) Trajectory. A howitzer fires a medium trajectory. It fires more like a long pass than a punt or screen pass. A howitzer can also fire high-angle fires like a mortar or direct fires like a gun, so it is a versatile combat asset.
(3) Firing capabilities. Howitzers have a low rate of fire. Although their firing rates vary with each weapon system, they average 2 to 3 rounds per minute. This sounds slow, but you must consider the principle of "massed fires." What this means to you is the artillery will tailor their fire for effect to meet the target. If you describe a small target, the artillery battery will attack it with one or two howitzers. If you describe a large target, the artillery will fire a platoon of three howitzers.
Figure 1-3. M198 howitzer.
If you have an even larger target, they will fire an entire battery of six howitzers. For extremely large targets, the artillery battalion can bring the fires of 3 batteries firing 18 howitzers to bear on one target. This is called massing fires.
- - -
Exercise: Complete items 1 through 4 by performing the action required. Check your responses against those listed at the end of this study unit.
1. Which of the following are three types of indirect fire. a. Naval gunfire, howitzers, close air support b. Howitzers, mortars, close air support c. Mortars, howitzers, tanks
d. Howitzers, naval gunfire, mortars
Matching: For items 2 through 4, match the type of indirect fire support in column 1 with the characteristics which best describes it in column 2. Place your responses in the spaces provided.
Column 1 Column 2
Indirect Fire Support Characteristics
___ 2. Naval Gunfire a. High trajectory, low rate of fire, light
___ 3. Howitzers artillery
___ 4. Mortars b. Flat trajectory, medium artillery, high rate of fire
c. Medium trajectory, medium artillery, massed fires
d. Light artillery, high rate of fire, high trajectory
Lesson 2. FIRE SUPPORT ORGANIZATION AND TARGETING
LEARNING OBJECTIVES
1. Identify the three members of the gunnery team with their proper duties. 2. List the duties of the fire support coordinator (FSC).
3. Identify the two types of targets and two types of planned targets. 4. Identify the target numbering system.
5. Define known point.
1201. The Gunnery Team
In using fire support, you will set in motion the actions of a great number of Marines than you may have initially realized. It takes a well-trained team to deliver effective fire support to the Marines on the modern battlefield. The gunnery team is comprised of three basic elements. Whether it be mortars, howitzers, or naval gunfire, these elements are: the observer, the fire direction center, and the firing element.
a. Observer. The observer is the Marine on the scene. He is responsible for accurately locating and identifying targets for the firing units.
b. Fire direction center. The fire direction center (FDC) consists of a group of Marines or sailors who take your request for fire and turn it into gunnery data and a fire order for the firing battery. The fire direction officer (FDO) decides how to attack the target based on your
description.
c. Firing element. The firing element consists of Marines or Sailors manning the tubes that will fire the ammunition to attack your target. Depending upon the type of fire support available to you, you decide whether you will use naval gun fire, a howitzer battery, or a mortar
section/platoon.
1202. The Fire Support Coordinator
Whenever a Marine Air-Ground Task Force (MAGTF) operates, one officer is designated as the fire support coordinator (FSC). It is his duty to coordinate many assets of fire support (including fixed and rotary wing close air support) and to use them to their best advantage in supporting the operation. He does this by organizing a fire support coordination center (FSCC) staffed by
The FSCC controls or coordinates your fire support needs in one of two ways, passive monitoring or active direction.
a. You may have one unit of fire support dedicated to your unit's support. This
section/battery/ship establishes direct contact to you and responds immediately to your calls-for-fire. If you are calling for fire from a unit that is dedicated to your support, the FSCC monitors the radio. If your target is suitably attacked by the dedicated unit, the FSCC normally remains silent and allows the mission to proceed. If the FSC decides that your target requires more or different support, he will take charge of the mission based on your call-for-fire.
b. You may not have any fire support assets dedicated to your unit. In this case, you will call directly to the FSCC with your call-for-fire. The FSC receives your call-for-fire, assesses your needs against available assets, and either controls the mission or assigns an element to you.
1203. Types of Targets
Each of the three supporting arms plan for and identify targets in their own way and for different purposes. Targets may include locations of enemy personnel or material or they may be
identifiable map/terrain features such as hilltops, road junctions, choke points, etc. There are two types of targets: planned targets and targets of opportunity. There are some different subtypes within these types.
a. Planned targets. Planned targets are identified prior to an engagement or movement. They are recorded on target lists maintained by the FSCC, units' headquarters, and the supporting arms' Fire Direction Center. There are three different types of planned targets:
(1) Scheduled targets are planned targets on which fire is prearranged by a time schedule (such as a preparation fire for an attack plan). The supporting arms will work up firing data ahead of time and fire at these targets in accordance with the time schedule of the particular operation.
(2) On-call targets are planned targets which are fired by the supporting arms upon request from the forward elements. The supporting arms will not normally work up data to these targets until they receive a request, but they will keep the targets on file for a faster response time.
be a target of opportunity. Once you fired upon it, it would either be destroyed or it would move out and the target would disappear.
Once fired upon, you may record targets of opportunity for future reference. We will discuss this in the upcoming study units. It is one way in which you will determine direction and location without a map or compass.
1204. Target Numbering
The Marine Corps designates targets using a system of assigned target number blocks. All targets are identified by a standard numbering system of two letters and four numbers. The letters and numbers are assigned to specific units by letter and number blocks. For example:
A Marine Expeditionary Unit (MEU) may be assigned target block AA0001 through AA9999.
The MEU will then assign target blocks within this set to subordinate units and organizations.
The FSCC is assigned AA1000 through AA1999. Alpha Company is assigned AA2000 through AA2999.
As an observer for Alpha Company, you are assigned AA2200 through AA2299. a. Your unit will be assigned a target number block. You should know your unit's target block. If you are a designated observer, you should be assigned a portion of that block for targeting and planning purposes.
b. If you are not assigned a target block, and you are only calling for fire on targets of opportunity, the supporting arms will assign a number from their block to any targets they fire.
1205. Known Points
You may often use known points to identify locations to the supporting arms. Known points are any points on the ground or map whose locations are known to both the forward observer and the firing unit. They may be such things as prominent terrain features, significant manmade objects (large buildings, bridges, monuments, etc.), or unit locations. Planned targets and targets of opportunity that have been recorded are also known points.
Exercise: Complete items 1 through 8 by performing the action required. Check your responses against those listed at the end of this study unit.
Matching: For items 1 through 3, match the member of the gunnery team in column 1 with the duties which best describe it in column 2. Place your responses in the spaces provided.
Column 1 Column 2
Member Duty
___ 1. Observer a. Locates and identifies targets to the firing
___ 2. Fire direction center unit
___ 3. Firing element b. Coordinates the fires of different supporting arms
c. Fires the rounds as directed
d. Receives call for fire and translates it into firing data
4. The duties of the fire support coordinator (FSC) include a. maintaining radio discipline during fire missions.
b. monitoring command and fire nets to coordinate the fire support assets and to use them to their best advantage.
c. instructing observers when to fire targets of opportunity. d. determining firing data for supporting arms.
5. Marine Corps units designate targets using a. individual unit designators.
b. observer target numbers.
c. an assigned block of two letters and four numbers. d. two numbers and four letters.
6. What are the two types of targets? a. Planned targets and on-call targets
7. What are the three types of planned targets?
a. Priority targets, on-call targets, and targets of opportunity b. Priority targets, scheduled targets, and on-call targets c. Priority targets, planned targets, and scheduled targets d. Priority targets, targets of opportunity, and on-call targets 8. A known point is
a. any target with its map location known to the forward observer and the firing unit.
b. any point on the ground which is known to the forward observer and the firing unit.
c. any point on the ground or map with its location known to the forward observer and the firing unit.
Lesson 3. ARTILLERY AMMUNITION
LEARNING OBJECTIVES
1. Identify the three effects of indirect fires with their descriptions. 2. Identify artillery shells by types.
1301. Effects of Artillery Fires
When you attack a target with artillery fires, you have many options available to you. There are three effects of a supporting arms fire mission: destruction, neutralization, or suppression. You must decide which effect you desire to cause. You will make your decision based on your knowledge of the situation, the enemy, and the effectiveness of artillery ammunition regarding which effect of indirect fire you need to employ.
a. Destruction. Target destruction means either a physical material target (such as a building, position, or vehicle) is destroyed or 30 percent or more casualties are inflicted against a personnel target. Target destruction usually requires the use of precision adjustment and/or high
expenditures of ammunition. Because of ammunition expenditure, destruction missions are rarely fired and must be well justified.
b. Neutralization. Neutralization fires disrupt the combat effectiveness of an enemy unit. Neutralization of a unit will normally be effected by causing 10 percent or more casualties. Neutralization fires use low ammunition expenditure when the target is attacked with the proper shell/fuze combination. Neutralization fires are the most common type of fire mission.
c. Suppression. Suppression of a target causes the enemy to temporarily stop functioning. Suppression of a target can be effective by causing the enemy to take cover or by blocking his vision temporarily. Suppression requires a low expenditure of ammunition; however, its inability to place lasting effects on a target makes it unsuitable for most targets.
1302. Types of Ammunition
There are many types of artillery ammunition available to you, as the forward observer. In the past, artillery was fairly limited to high explosive, smoke, and illumination. Recently there have
a. Shell, High Explosive (HE). Although HE is a single shell, its versatility with different fuze combinations causes fire support planners to consider each of its fuze combinations as a different shell. There are four types of fuzes available for use on the HE shell that cause different effects with the round. The four types of fuzes are quick, delay, time, and proximity.
(1) Fuze, Quick (Q). Quick is a form of point detonating (PD) fuze, and it causes the round to explode upon impact.
It is more effective against It is less effective against v Personnel standing v Personnel dug in v Unarmored vehicles v Armored vehicles v Light material v Hardened material
v Swamp or soft sand surfaces
(2) Fuze, Delay (D). Delay is also a form of PD fuze. It is designed to delay the explosion of the round for 0.05 seconds after impact. This minor delay causes the round to penetrate soft surfaces slightly or to ricochet off hard surfaces.
It is more effective against It is less effective against v Light earthworks v Soft sand or marshy ground v Buildings v Personnel dug in
v Dense wooded areas
(3) Fuze, Time (Ti). Time fuzes can be set to explode at a given time anywhere along the trajectory of the round. They are most commonly used to create an air burst 20
meters above the target. An air burst will have greater shrapnel dispersion and effectiveness than a graze (ground) burst. A time fuze cannot be used in high angle fires (mortar type trajectory) because the speed of the falling round makes timing the burst difficult.
It is more effective against It is less effective against
v Personnel in the open v Personnel with overhead cover v Personnel dug in v Personnel in dense woods v Personnel in unarmored v Armored vehicles
(4) Fuze, Proximity (VT). The proximity fuze is a radio-activated fuze that causes the round to explode at a specified height off of the ground (20 meters for the older models, and 7 meters for the newer models). VT will deliver a correct air burst every time, even in high angle fires. Its effectiveness is the same as that of the time fuze.
Note: The 7-meter height of burst on the newer model VT fuze can cause
inexperienced observers to spot the rounds as a graze burst instead of an air burst. You should be aware of this so that you do not inaccurately report a fuze malfunction. Careful comparison of the appearance of quick fuze graze bursts will help the observer realize when the VT is not a graze burst.
b. Shell, Improved Conventional Munitions (ICM). ICM is a base-ejection projectile filled with grenades. A base-ejection projectile is a hollow shell with its base attached by a thin weld and shear pins. Fuze function forces the contents of the shell onto the base, pushing it off, and dumping the contents of the shell out of the bottom. All base-ejection projectiles use a
mechanical time fuze to cause an air burst for proper functioning. The base-ejection causes a large dispersal effect for the grenades. There are two types of ICM, anti-personnel (APICM or just ICM) and dual-purpose (DPICM). They are both extremely effective against personnel, but the DPICM shell is also effective against light armored vehicles.
(1) APICM. The original ICM grenade is a "bouncing Betty." The grenade is contained in a canister that has spring action stabilizer wings to cause it to land right side up. The canister strikes the earth and the grenades pop up and explode. These grenades are extremely effective against personnel in the open, but are ineffective on material or against personnel in snow, water, or heavily wooded areas. At present, APICM is being phased out of service, so if an observer calls for ICM, he will more than likely receive DPICM.
(2) DPICM. DPICM grenades are cylinder shaped grenades that explode and cause the dual action of a shaped explosion downward and fragmentation upward and sideways. The shaped explosion will penetrate light armor (2" of homogeneous steel), and the fragmentation is effective against personnel. The DPICM grenade is guided base down by a rubber band attached to the top that acts as a stabilizer.
Note: ICM should not be used against target areas which Marines will have to enter, especially in heavily wooded areas. The grenade stabilizers can become
inventory, shell, WP (the conventional model) and shell, WP smoke (a newer version). Both shells have similar effectiveness.
(1) Conventional WP. The original WP shell is simply a hollow artillery round with an explosive burster tube in the center filled with white phosphorus. Fuze function (PD, Time, or VT) causes the burster tube to expand, splits the shell, and exposes the WP to the air. Because this happens so rapidly, the burst appears to be explosive and chunks of WP are sprayed out of the shell. The majority of the WP remains in or near the shell and this is what causes the conventional WP round to form its distinctive pillar of white smoke.
(2) Improved Smoke. The improved smoke round (also called WP smoke) is a
time-fuzed, base-ejection projectile filled with felt wedges which are soaked in WP. Fuze function in the air causes the round to trail the WP felt wedges behind it spreading them out over a greater area than the old WP round's chunks. This causes the WP smoke round to have a better screening effect with less tendency of the smoke to form a pillar.
d. Shell, Smoke (HC). The HC (hexachloroethane) round is a base-ejection projectile filled with a smoke canister. HC smoke is a more effective screening agent than WP because it has a longer burn time and less tendency to pillar. Smoke is effective for screening all targets, whether the user wishes to obscure the target or himself from the target.
e. Shell, Illumination (Illum). Illumination shells are used for illuminating areas of suspected enemy activity, providing illumination for night adjustment, harrassing enemy positions, marking targets for attack by close air support, and "washing out" enemy passive night-sight systems. The illumination lights up the battlefield using approximately 1,000,000 candlepower.
-Exercise: Complete items 1 through 10 by performing the action required. Check your responses against those listed at the end of this study unit.
Matching: For items 1 through 3, match the desired effect of artillery fires in column 1 with the definition which best describes it in column 2. Place your responses in the spaces provided.
Column 1 Column 2
Effect Definition
___ 1. Destruction a. Target temporarily ceases
___ 2. Neutralization activity, requires high ammunition expense ___ 3. Suppression b. At least 10 percent personnel casualties,
requires low ammunition expense c. At least 30 percent personnel casualties,
requires minimum ammunition expense d. At least 30 percent personnel casualties,
requires high ammunition expense 4. What are the five types of artillery shells?
a. HC, Bee Hives, ICM, HE, and Illum b. HE, HC, WP, Smoke, and Illum c. WP, HE, Smoke, Illum, and ICM d. ICM, Smoke, Illum, HE, and Bee Hive 5. What are the four types of HE fuzes?
a. PD, Quick, Ti, and VT b. PD, Quick, Ti, and Delay c. Ti, Delay, VT, and PD d. Delay, VT, Ti, and Quick
Matching: For items 6 through 10, match the type of artillery shell in column 1 with the description which best identifies its proper usage in column 2 (put X on the spaces for the shells that you cannot match).
Column 1 Column 2
Shell Description
___ 6. HE a. Is more effective against personnel than
other types
___ 7. WP b. Can be used to start fires or for screening
___ 8. Smoke c. Is versatile when used with different fuzes
___ 9. ICM d. Is used to observe the battlefield
___ 10. ILLUM e. Used for screening and obscuration
UNIT SUMMARY
In this study unit, you learned some fundamentals of indirect fire support. Your understanding of how the gunnery team and the fire support coordinator will bring you effective support is essential for maximizing your combat power and effectiveness. When you call for artillery support, you must understand what you are trying to accomplish and what tools are available for you to use. Now you know the effects artillery can produce and the ammunition used to cause these effects. In Study Unit 2, you will learn how to locate targets on the ground in terms of calling for fire. Lesson 1 Exercise Solutions
Reference
1. d. 1101
2. b. 1102b
3. c. 1102c
Lesson 2 Exercise Solutions Reference 1. a. 1201a 2. d. 1201b 3. c. 1201c 4. b. 1202 5. c. 1204 6. d. 1203 7. b. 1203a(1) 8. c. 1205
Lesson 3 Exercise Solutions
Reference 1 d. 1301a 2. b. 1301b 3. a. 1301c 4. c. 1302 5. d. 1302a 6. c. 1302a 7. b. 1302c 8. e. 1302d 9. a. 1302d 10. d. 1302e
STUDY UNIT 2
TARGET LOCATION
Introduction. Before you can call-for-fire successfully, you must first locate the targets in relation to the firing unit. Indirect fire support means that the firing unit cannot directly see the target. They are dependent upon you to get them on target. The key to successful fire support is the accurate target location. The accurate target location is the result of a thorough map analysis, a good terrain association, and an accurate direction and distance. Determining direction and distance is an essential part of map/terrain association, target location, and adjustment of fire. In the first lesson of this study unit, you will learn methods for performing a thorough map/terrain association of the target area. The second and third lessons of this study unit will teach you to determine directions and distances. The fourth lesson will connect these tools to the three methods used to identify target location to the firing unit: polar plot, grid coordinates, and shift from a known point.
Lesson 1. MAP/TERRAIN ASSOCIATION
LEARNING OBJECTIVES
1. Identify the three operations the observer must perform to be oriented. 2. Identify the purpose of a terrain sketch.
2101. Orientation
To locate targets for the supporting arm, you must first orient yourself to the target area. You will accomplish three things. First, you must establish your location. Second, you must locate your target or point you can use for a reference. Third, you must determine the direction from you to the target or reference point.
a. Establish location. You must locate yourself in relation to the map as accurately as you can. With enough practice at land navigation and map reading, your self-location by map
inspection/terrain association will be accurate enough for you to conduct fire missions. If possible, you should attempt to locate your position more accurately by performing a map
resection or other accurate means such as Global Positioning System (GPS), or Position Location and Reporting System (PLRS).
b. Locate target. You must be able to locate the target relative to your position both on the ground and on your map. If you don't have a target, you use a terrain or manmade feature that you can also locate on your map. The methods used to locate targets will be discussed in the following lessons.
c. Determine direction. You must establish the direction to your target whether or not you have a map. This can be accomplished by several different means: compass, cardinal directions, or by terrain association. If you are using a map you can also scale direction on your map with a protractor. Locate your position on the map and from your location scale the direction to
prominent terrain features with a protractor.
(1) Compass. Using a compass, you can orient yourself by orienting your map. Do this in the following manner: with the map in front of you, place the straightedge of the compass along one of the north/south grid lines. Turn the map and compass together until the needle is on north. Move the map and compass together to cause the needle to match the declination diagram (located in the legend of the map at the bottom) in number of mils left or right of grid north. Now your map is oriented to grid north. (2) Cardinal direction. If you have neither map nor compass, associate the limits of your
target area to the cardinal directions (north, south, east, west). The cardinal directions are
North: 0 or 6400 Northeast: 0800
East: 1600 Southeast: 2400
South: 3200 Southwest: 4000
West: 4800 Northwest: 5600
Note: Direction would be measured in mils, and a grid direction should be given in four-digits when calling-for-fire. Grid azimuths are measured in a clockwise direction and there are 6400 mils in a circle.
(3) Terrain association. If you don't have a compass to orient your map with, use prominent terrain features. Put your map in front of you and associate what you see with the contour lines and symbols on your map. You can make a thorough study of the terrain by constructing a terrain sketch.
2102. Constructing a Terrain Sketch
A terrain sketch (fig 2-1) is a rough panoramic drawing of the area of observation prepared by the observer. Once constructed, it serves as a rapid means of identifying directions to reference points. A terrain sketch also provides a rapid means of orienting relief personnel. Items that should be included in a terrain sketch are
v The skyline (horizon)
v Prominent features both natural and manmade (hill masses, ridgelines, bodies of water, trees, roads, buildings, antennas, towers, battlefield debris, etc.)
v Labels (reference points, known points, targets)
Figure 2-1. Terrain sketch.
Reference points should be chosen across the area at intervals not over 200 mils apart to aid in rapidly identifying directions. Each labeled item should include as much information as possible without cluttering the sketch. Identify the information by numbers, reference point names, and known point designations and place at the top of the "T" (fig 2-1). Labels for direction, distance, altitude, and grid should be placed on the right side of the "T." Reference points usually only require direction, but known points and targets should have direction, distance, and grid. Terrain sketches are never complete, you must continually refine and update them.
-Exercise: Complete items 1 through 3 by performing the action required. Check your responses against those listed at the end of this study unit.
1. To orient yourself to the target area, you must first ____________, then ___________, and finally ____________.
a. establish direction, establish your location, locate your targets b. establish direction, locate your targets, establish your position c. establish your position, establish direction, locate your targets d. establish your location, locate your target, determine direction 2. A terrain sketch is which of the following?
a. Precise record of targets you have located
b. Technically correct representation of the target area from your viewpoint c. Reference tool for determining directions within the target area
d. Sketch of targets and known points you can see 3. To establish direction you can use which of the following?
a. Compass, cardinal directions, terrain sketch, terrain analysis, binoculars b. Compass, terrain sketch, map and protractor, terrain association, observed fire
fan
c. Terrain analysis, scale, terrain sketch, cardinal directions
Lesson 2. DETERMINING DIRECTION (AZIMUTH) TO THE TARGET
LEARNING OBJECTIVES
1. Identify the types of direction used to locate targets.
2. Identify five methods of determining direction to objects in the target area. 3. Identify the methods for determining angular deviation.
4. Determine angular deviation using a binocular reticle pattern. 5. Determine angular deviation using a hand measurement.
2201. Types of Direction
There are several types of direction that can be used to locate targets; namely, observer target line, gun target line, cardinal/intercardinal direction, and arbitrary reference feature.
a. Observer target line (OT line). The observer target line is an imaginary line from the observer to and through the target. The OT line is the direction most commonly used in target location and adjustment.
b. Gun target line. The gun target line is an imaginary line from the guns to and through the target. It is most commonly used by aerial observers to adjust fire, but can be used by an observer on the ground.
c. Cardinal/intercardinal direction. This is the use of the eight cardinal/intercardinal directions (N, NE, E, SE, S, SW, W, NW). It is the least accurate, but at times you may need to use it. d. Arbitrary reference feature. You may use a natural or manmade feature (such as a
north-south road or river) from which to reference target location and/or adjustment of fire. This may be used in situations where transmission of the OT direction may compromise your location.
2202. Methods of Determining Direction
Determining direction is an essential skill for calling for and adjusting fire. Direction is a term used to indicate the bearing of the spotting line. It is an integral part of terrain-map association, adjustment of fire, and target location. There are five methods by which you can determine direction; namely, measuring from a reference point, using a compass, scaling from a map,
b. Using a compass. Using a compass you can measure a direction to an accuracy of 10 mils. If you are using a lensatic compass, you read the direction in mils using the outer scale. You must then convert the magnetic reading to a grid azimuth. Follow the instructions in the declination diagram of your map. Remember, for converting azimuths only, the rule is left add/ right
subtract. If magnetic north is to the left of grid north, you will add the value of the G-M angle to your reading to convert magnetic azimuths to grid azimuths. If magnetic north is to the right of grid north you subtract the value of the G-M angle from your reading. If you are using an M-2 compass, you do not have to convert. You will declinate your compass before using it and the readings will be grid azimuths.
c. Scaling from a map. Using a protractor, you can scale direction from a map to an accuracy of 10 mils.
d. Estimating. This is the least accurate method but can be used if you have no other means. You should be able to visualize a cardinal direction by remembering the sun and moon rise in the east and set in the west. If you know you are facing east, then north is to your left, south is to the right, and west is to the rear.
e. Using other measuring devices. New equipment is constantly being developed to help provide fast and accurate means to determine direction. Laser equipment, such as the AN/PAQ-3 Modular Universal Laser Equipment (MULE), is extremely fast and is accurate within a 2 mil accuracy. The MULE is issued to artillery forward observers and naval gunfire spotters.
2203. Angular Deviation
You must be able to determine angular deviation (measurement) to determine direction and also for determining horizontal distance for target location and corrections in adjustment. You can determine deviation by using binoculars, a battery commanders (BC) scope, an aiming circle or by hand measurement. To determine direction to a point or target, you measure the deviation
(horizontal distance) from a point of known direction to the point you are measuring. Regardless of the means used to measure, you must remember azimuths increase to the right and decrease to the left. You can remember this by using the right add/left subtract (RALS) rule. If the target is to the right of the reference point, you add the deviation to the known direction. If the target is to the left, you subtract the difference from the known direction.
2204. Determine Angular Deviation Using Binoculars
a. The best way to quickly measure an angle is to use the scale on a binocular recticle pattern. Figure 2-2 shows the reticle patterns that you will see in Marine Corps issue binoculars. The left illustration is the binocular reticle pattern for the M19 binoculars. The right illustration is the reticle pattern for the M17 binoculars. The difference between the two is in the vertical scale.
Figure 2-2. Binocular reticle patterns.
The horizontal scale is graduated in 10-mil increments, numbered one through five, to the left and right from the center (vertex) of the scale. When using these increments, you will identify them to yourself as being either left or right of your known point.
(1) To measure the deviation between the point of known direction and your target, your first step is to align the vertex (center) of the scale with the known point (fig 2-3). The second step is to determine which number graduation is in line with the center of the target.
You would read this measurement as 30 left.
Figure 2-3. Measuring deviation.
(2) When the known point and the target are farther than 50 mils apart, you can't align the vertex with the known point. You must measure by aligning one end of the scale with your known point and reading the total number of mils to the target (fig 2-4).
You would read this measurement
as 80 right.
Figure 2-4. Target and known point more than 50 mils apart.
(3) When the known point and the target are more than 100 mils apart, you won't be able to fit both in the reticle pattern. When this happens you must "leapfrog" to measure the deviation. To do this
vMove the horizontal scale left or right until the known point is located at one end of the scale.
vMeasure the deviation from the known point to this reference point then move your binoculars until the reference point is at the end of the scale where the known point was. Measure the remaining number of mils to the target.
v Now apply the total deviation to the known point direction to get the target direction (figs 2-5 and 2-6).
Read Read Add the
this this total of
as 85 as 45 the two
right right then you
subtract that from
the known
distance
Figure 2-5. Leapfrogging. Figure 2-6. Leapfrogging.
The reading of the measurement in figure 2-5 was 85 right and the reading in figure 2-6 was 45 right giving you a total measurement of 130 right. Using the RALS rule (right add/left subtract) add 130 to the known point direction, and you get the direction to the target.
(4) If the target and your known point are farther apart than one reference point will cover, you must continue to use the leapfrog method until you can reach the target. b. When operating in a static situation, you can determine angular deviation or measurement by using a BC scope or an aiming circle. These instruments are extremely useful when accurate measurements are paramount, such as for precision adjustments, for measuring vertical angles, or for night observation. Both the BC scope and aiming circle are usually only available from artillery units.
2205. Determine Angular Deviation Using a Hand Measurement
In situations where speed is essential, or when you have no other means, you can use your hand or fingers to measure deviation. To use this method accurately, you must remember to fully extend your arm (elbow locked) each time. With your arm fully extended, palm pointed away from you, place your hand or fingers between your point of known direction and the target
Figure 2-7. Angular deviation measurements.
To increase accuracy, you should calibrate your hand. The values may vary slightly depending on size of the hand. To calibrate your hand, you simply measure the deviation between objects with your hand and check the measurement against known deviation or measure the deviation with an instrument.
-Exercise: Complete items 1 through 5 by performing the action required. Check your responses against those listed at the end of the study unit.
1. What are two methods of determining directions in the target area? a. Leapfrogging and hand measurement
b. Hand measurement and binocular reticle pattern c. Measuring from a reference point and using a compass d. Directional instrument and binocular reticle pattern
3. What are the two methods for measuring angles between objects? a. Leapfrogging and hand measurement
b. Hand measurement and binocular reticle pattern c. Directional instrument and hand measurement d. Leapfrogging and binocular reticle pattern
4. In the figure below, what is the angle between the vertex and the target?
a. 4.5 mils c. 45 mils
b. 40 mils d. 50 mils
5. You have calibrated your hand as follows: v Fingers 40 mils each
v Closed fist 200 mils v Spread hand 400 mils
Lesson 3. DETERMINING DISTANCE
LEARNING OBJECTIVES
1. Determine the distance to a target by using the "flash-to-bang" method given a situation.
2. Identify the procedures used to determine distance to a target using an observed fire (OF) fan and terrain association.
3. Determine lateral distance to a second point given a point of known distance and an observation.
2301. Distance
Once you have determined the direction, you must determine the distance to the target. Distance is the horizontal space between a reference point and a target or between you and the target. Determining a distance is normally the most difficult variable in target location. It is also used in the adjustment of fire. The standard unit of measure for a distance is the meter. Distance can be determined by one, or a combination, of these methods: lasers, flash-to-bang, or estimation. a. Lasers. Lasers are the preferred method for determining observer to target (OT) distance. When a laser is used, distance can be determined to an accuracy of 10 meters. The MULE and the AN/GVS-5 laser rangefinder provide an observer with the fastest and most accurate means of determining distance.
b. Flash-to-Bang. Because we know that sound travels at a speed of 350 meters per second, we can use sound to estimate distance. To use this method, you must count the number of seconds between the detonation of the round (FLASH) and the sound (BANG) of the impact. Multiply the number of seconds by 350. The answer is the distance in meters from the observer to the target or round. Use the equation
FLASH-TO-BANG (in seconds) X 350 = DISTANCE
This method has several uses to the observer. It not only determines a distance, it can be used to confirm a distance. It can also be used to determine the distance to the muzzle flash of enemy
(1) A mental estimate is made by use of a known unit of measure. Distance is estimated to the nearest 100 meters by determining the number of known units of measure, such as a football field (100 yards), between you and the target.
(2) You must consider the following effects when estimating a distance: vObjects appear nearer
v In bright light
v When you are looking down v When you are down a road
v When you are looking across water, snow, or a uniform surface such as a desert
v When the background is in contrast to the color of the object vObjects appear more distant
v In poor light or fog
v When only a small part of the object is seen
v When looking over a depression, most of which is visible v When the background is similar in color to the object
(3) When visibility is good, distance can be estimated by using the appearance of tree trunks, their branches, and foliage (using the naked eye) in comparison to map data. (4) You must always do a terrain/map analysis to assist in estimating distances. When
you are looking in a specific direction, the estimation of distance can be enhanced by studying the terrain to associate what you are seeing on the ground with what you see on your map. The use of an observed fire (OF) fan helps you associate map and compass direction.
(5) Altitude is the vertical distance measured from sea level. The standard unit of measure for altitude is the meter. Altitude is determined from a map study using the contour lines and contour interval.
2302. Observed Fire (OF) Fan
The OF fan is a transparent protractor that can be used to show the direction and distance on the map. It helps the observer identify on the map what he sees on the ground. The OF fan has 17 radial lines that are 100 mils apart and cover a total area of 1600 mils. The radial lines represent OT direction. The OT distance is represented by arcs marked on the fan every 500 meters and labeled every 1000 meters beginning at 1000 and extending to 6500. The OF fan is available
a. Orienting the OF fan. To use your OF fan effectively you must first orient your map, locate your position, and mark your location on the map. Then locate a reference point in the direction of your area of operation. Now you are ready to orient your OF fan by performing the following steps:
(1) Place the vertex of the OF fan over your location.
(2) Place the center radial line in the direction of your reference point.
(3) Move the fan slightly until one of the radial lines is parallel to a grid line (regardless of what direction to the reference point may be), one of the radial lines will always point to a cardinal direction.
(4) Attach the OF fan in position on the map by using a piece of tape along one edge of the fan. The fan can then be lifted, if required, to inspect the map without disturbing its orientation.
(5) With a marker pen or grease pencil, number the even directions (every second radial line) dropping the last two zeros.
b. Determine target location. To determine the target location, you must first determine direction using one of the methods previously discussed. Sight along that direction on your OF fan and map until you associate the terrain around the target with the proper contours on the map. Observe the ticks on your OF fan, or measure with a protractor, and read the distance +/- 100 meters. In figure 2-8, you would determine the distance to the target located at grid 531269 as 3200 meters.
Figure 2-8. Target location using the OF fan.
2303. Determining Lateral Distance
Lateral distance is the distance left or right, from one object to another, perpendicular to your line of sight. Determining lateral distance is important for you in order to adjust fire and for locating targets using the shift from a known point method of target location, which will be discussed in the next lesson. The accuracy of your lateral distance estimation will depend upon how well you determine the distance from you to the target. Once you have established the distance from you to the target, you will use the mil relation formula (W=R x m) to convert the measured angle in mils to a lateral shift in meters. This formula is based on the rule that 1 mil of arc, at a distance of 1000 meters, will equal 1 meter of lateral distance. It's similar to how windage and elevation changes on your rifle create different points of impact at different ranges.
The mil relation formula: W = R x m
W = Width or lateral shift (distance) in meters
Follow the sample problem to use the mil relation formula to determine a lateral distance. Looking at figure 2-9, follow the step-by-step instructions:
Figure 2-9. Lateral distance determination. Known: Distance to known point-2500 meters angle in mils-60 mils
Step 1: Find the value of R. Divide the distance to the known point by 1000, 2500/1000 = 2.5. The value of R = 2.5.
Step 2: The measured angle is 60 mils. The value of m = 60.
Step 3: To find W, multiply the value of R by the value of m, 2.5 x 60 = 150. The value of W = 150 meters.
Exercise: Complete items 1 through 3 by performing the action required. Check your reponses against those listed at the end of this study unit.
1. Which of the methods for determining distance is the most accurate?
a. Estimation c. Flash-to-bang
b. Lasers d. OF fan
2. You have observed an enemy crew served weapon firing. You saw the muzzle flash and counted 4 seconds until you heard the report of the weapon. What is the distance to the enemy?
a. 140 meters c. 1400 meters
b. 1240 meters d. 12400 meters
3. When determining distance to a target using terrain association and the OF fan you read distance to the target to +/- ________ meters.
a. 1 c. 50
b. 10 d. 100
4. You have observed a target to the right of a known point. The distance to the known point is 1500 meters. You measured the angle between the known point and the target to be 50 mils. What is the lateral distance from the known point to the target?
a. 50 meters c. 500 meters
Lesson 4. METHODS OF TARGET LOCATION
LEARNING OBJECTIVES
1. Locate a target by polar plot given a terrain sketch and a reference point.
2. Locate a target within 100 meters expressed as a six-digit grid, given a map and a coordinate scale.
3. Determine the range and lateral shift to a target given a known point and orienting data.
2401. Polar Plot
The polar plot method of target location consists of three elements: direction, distance, and vertical shift. You determine these elements and report them to the FDC. The primary advantage of the polar plot method is that it is fast and can be done without a map. If a laser rangefinder is used, the polar plot method is very accurate. A disadvantage is that your position must be known to the firing unit. This may require you to send a coded message to your location (including altitude) before sending the call-for-fire. To perform a polar plot, follow these steps:
Step 1: Determine direction to the target to the nearest 10 mils.
Step 2: Determine/estimate the distance to the target to the nearest 100 meters.
Step 3: Determine the difference in altitude between your position and the target to the nearest 5 meters. You need not report a vertical shift of less than 30 meters.
2402. Grid Coordinate
Target location by grid coordinate is a natural extension of the polar plot method. The FDC doesn't need to know the observer's location to use the grid method. Normally you locate targets to the nearest 100 meters (six-digit grid). You do the plot on your map and refine with terrain association, then read the grid where the target plots on your map. When additional accuracy is required (for registrations or locating known points) you should locate targets to the nearest 10 meters (eight-digit grid).
b. Supplementary data. With the use of your OF fan, you can determine six-digit grids easily and, with good observations, you can determine eight-digit grids accurately. Follow these steps to determine a grid using your OF fan.
(1) Determine the direction to the target using one of the methods covered in Lesson 2. (2) Determine distance to it with one of the methods taught in Lesson 3.
(3) Find the direction on or between the rays of the fan.
(4) Follow along the direction until you are at the determined distance by using the tick marks on the rays.
(5) Plot the point and then scale the grid from the map.
2403. Shift from a Known Point
The shift from a known point method of target location is when you locate a target in relation to a known point (fig 2-10). This method offers several advantages. It is accurate, you don't have to use a map, and your location need not be known to the FDC. However the FDC must know the location of the known point. The known point may be a terrain reference point previously recorded or a target that was previously fired and recorded. To perform a shift from a known point, follow these steps:
a. Identify the known point to be used to the FDC by target or known point number. b. Determine the OT direction to the nearest 10 mils and report as "direction _______." c. Determine the lateral distance between the known point and the target to the nearest 10 meters, using the mil relation formula you learned in Lesson 3, report this to the FDC as "right ____(or left ____)." If the deviation is greater than 600 mils, the mil relation formula becomes inaccurate, you should use the grid method of target location.
d. Determine the range shift from the known point to the target to the nearest 100 meters. If the target is further from you than the known point, you report "add ____." If the target is closer to you than the known point, you report "drop ____."
e. Determine the vertical difference between the known point and the target to the nearest 5 meters, if the difference is greater than 30 meters, you report this as "up ____ " (or "down____").
Figure 2-10. Shift from a known point.
Figure 2-10 gives an example of a shift from a known point method of target location. The following computations are for figure 2-10.
Mil relation formula: W = R x m R = (known distance/1000) m = (angular deviation 80m) W = 2.1 x 80 = 168.0
168.0 rounded to nearest 10 M = 170 M W = Right 170
Distance = Estimated distance - Known distance 2900 - 2100 = Add 800
Exercise: Complete items 1 through 3 by performing the action required. Check your responses against those listed at the end of this study unit.
Situation: Select the correct answers using the information given and illustrations 1 and 2. The first illustration is your observation of your target and a stalled tank. The peak on which your reticle pattern is centered is known point 1. The distance from you to the tank is 3800 meters.
The second illustration is your oriented map and OF fan with known point 1 (KP0001) plotted at grid 714461. You have the following data for known point 1: direction 4790, distance 5900, altitude 2450. The contour interval of the map is 20 meters.
Illustration 2. 1. What is the grid to the target?
a. 736473 c. 739467
b. 736464 d. 740471
2. What is the correct polar plot of the target?
a. DIRECTION 4745, DISTANCE 3550, DOWN 80 b. DIRECTION 4835, DISTANCE 3850, UP 80 c. DIRECTION 4840, DISTANCE 3800, DOWN 60 d. DIRECTION 5090, DISTANCE 3000, UP 60
UNIT SUMMARY
In this study unit, you learned the methods and techniques for locating targets within the target area. You learned the basics of map/terrain association and the determination of direction and distance from yourself to objects or from objects to objects. As an observer, you will be required to perform these actions repeatedly. In Study Unit 3, you will learn to call for, adjust rounds onto, and engage targets in fire for effect. In adjusting rounds and reporting their effects, you will again be required to associate your observations to the map and to determine direction and
distances.
Lesson 1 Exercise Solutions Reference
1. d. 2101
2. c. 2102
3. d. 2101c
Lesson 2 Exercise Solutions Reference
1. c. 2202
2. b. 2202b
3. b. 2203
4. c. 2204a
5. d. 2205
Lesson 3 Exercise Solutions Reference
1. b. 2301a
2. c. 2301b
3. d. 2302
4. b. 2303
Lesson 4 Exercise Solutions Reference
1. b. 2402
2. c. 2401
STUDY UNIT 3
CONDUCTING FIRE MISSIONS
Introduction. In the previous study unit, you learned to locate targets by determining distances and measuring angles. In this study unit, you will learn how to conduct your fire missions, artillery communications, spotting and corrections, and adjustments on fire for effect.
Lesson 1. FIRE MISSIONS
LEARNING OBJECTIVES
1. Identify one of the three desired effects of a fire mission given a scenario. 2. Select one of the four types of fire missions given a scenario.
3. Select a type of adjust fire mission used to locate the target. 4. Determine if a fire for effect mission is used given a scenario.
5. Determine if a suppression mission is conducted properly given a situation. 6. Determine if an immediate suppression mission is conducted properly given a
situation.
3101. Three Types of Effects of Fire Missions
When you engage a target with artillery, you will be firing to achieve one of three effects upon the enemy. You will be firing to destroy, neutralize, or suppress the enemy.
a. Destruction. To destroy a target you are either going to actually destroy a material target by fire or cause 30 percent or more casualties against a personnel target (which will render a unit ineffective for combat). To destroy a material target you will conduct a precision fire mission, which is an extended adjust fire mission requiring target "hits." Destruction of a material target requires that an artillery piece or battery expose itself to detection and counterfires. Destruction
c. Suppression. Suppression missions will temporarily stop an enemy unit from being effective. Suppressive fires will either cause an enemy to seek cover or, by using smoke,
temporarily obscure his vision of the battle area. Both the suppression and immediate suppression missions yield suppressive results only during the time the fire is being delivered.
3102. Types of Fire Missions
There are four types of fire missions: adjust fire, fire for effect, suppression, and immediate suppression. You will achieve destruction, neutralization, or suppression of the enemy by performing one of the four types of fire missions. Each type of fire mission is designed to bring fires to targets for different effects, except the adjust fire mission, which is a method of target location prior to conducting either fire for effect or suppression.
3103. Adjust Fire (AF) Mission
Adjust fire missions are requested when you decide an adjustment will be needed. An adjustment may be needed because of questionable target location or lack of registration corrections. There are two types of adjustment missions: area fire and precision fires. For precision fires, adjustment will be necessary no matter how accurate your target location is.
a. Area fire. Artillery, mortars, and naval guns are all area fire weapons; therefore, most of your targets will be area targets. Area fire is used on area targets. Since many area targets can move, the adjustment should be made as rapidly and accurately as possible to keep the target from escaping. A well-defined point should be selected at or near the center of the area to be attacked and used as an adjusting point. To achieve surprise, fire could be adjusted on an auxiliary adjusting point and when completed, the fire for effect could be shifted to the target. Normally, adjustment is conducted with one adjusting weapon.
b. Precision fire. Precision fire adjustments are conducted with one weapon on a target. It is used either to obtain registration corrections or to destroy a target. When the mission is a
registration, it is initiated by the FDC with a message to observer. If the target is to be destroyed, you must announce, "Destruction," in the call-for-fire.
3104. Fire for Effect (FFE)
Firing for effect, without previously adjusting to the target, is the most effective way of engaging the enemy with indirect fire. Adjusting rounds will alert the enemy and cause him to change his posture, thereby nullifying more than half of your effectiveness. The fire for effect mission is used when you have accurate target location and are certain the first volley will impact on target with little or no adjustment. With first round FFE you will achieve the maximum potential damage to