EPS 101/271 Lecture 11:GPS Data Collection, Mapping Using GPS and Uncertainties in GPS Positioning
How GPS data is collected in GeoMapper
Setting Time interval for reporting GPS measurements Modes of operation and their advantages
Static(when you stop) anddynamicmodes (while you walk) Difference of “Classroom learning” versus “Hands-experience” Using IT Technology to Determine Uncertainties in GPS data:
National Geodetic Survey Database on survey monuments Precisionversus Accuracy: What do they really mean ? Survey monuments
S ( d ifi )
PIDS (Permanent Identifiers)
Universal Transverse Mercator (UTM) projection and the Meter Caution: A computer and the GPS will do exactly what you tell them
to do, even if it is different from what you really want- you have to be in charge and manage the digital tools
Chilean Earthquake 8.8 Richter Magnitude Thrust fault
NY Times: Scientists Taking Steps to Defend Work on Climate
http://www.nytimes.com/2010/03/03/science/earth/03climate.html?scp=1&sq=Climate&st=cse
Practicing Science: Based on an honor code
A chain of understanding only as good as its weakest link
You have to be there to be a participant in science Science is about your personal priorities
4
Last
Zone 10-S Global UTM Grid
UTM Easting
Do not start up a GPS until you are outdoors with a clear view of the Sky in all directions.
Be patient until a sufficient number of satellites (4) are giving readings With a signal to noise ratio > 32.
Never hit the cancel button
3 useful GPS collection modes: Static mean correctable Minimum distance
Every time- useful in starting up GPS
Note: Center is 60 degrees not 90
Most accurate mode to locate points of interest- stop at each point … Hit Restart wait at least >10 seconds hit Accept, then go to next spot
Not-checked
Static mode-when you stop walking Locate yourself, get a point on a contact Plot strike and dip
Dynamic mapping (while you walk)
Minimum Distance
We can map contacts just by walking them
How GPS data is collected in GeoMapper Setting Time interval
Modes of operation and their advantages
Static(when you stop) anddynamicmodes (while you walk)
Using IT Technology to Determine Uncertainties in GPS data: Precision: Repeatabilityof measurements
Accuracy:Correctnessin relation to anaccepted standard Accuracy: Correctnessin relation to an accepted standard What does “Randomversus Systematicerror mean ? Geodetic Measurements
Survey monuments
PIDS (Permanent Identifier)
NGS Points Listed at Stadium PID HT1891 Northing: 4,191,785.289 Easting: 566,004.288 Elev. 144.87 meters How do we know this ?ow do we ow t s ?
NGS DataBase
The NGS Data Sheet
1 National Geodetic Survey, Retrieval Date = FEBRUARY 27, 2004 HT1891 *********************************************************************** HT1891 DESIGNATION - STADIUM A
HT1891 PID - HT1891 HT1891 STATE/COUNTY- CA/ALAMEDA HT1891 USGS QUAD - OAKLAND EAST (1997)
HT1891 ___________________________________________________________________ HT1891* NAD 83(1992)- 37 52 16.16975(N) 122 14 58.33062(W) ADJUSTED HT1891* NAVD 88 - 144.87 (+/-2cm) 475.3 (feet) VERTCON HT1891 ___________________________________________________________________ HT1891 EPOCH DATE - 1991.35
HT1891 LAPLACE CORR- 3.66 (seconds) DEFLEC99 HT1891 GEOID HEIGHT- -32.22 (meters) GEOID03 HT1891
HT1891 HORZ ORDER - FIRST
HT1891 VERT ORDER - FIRST CLASS I (See Below) HT1891
HT1891; North East Units Scale Factor Converg. HT1891;UTM 10 - 4,191,785.289 566,004.288 MT 0.99965366 +0 27 38.6
Accuracy: relative to a known GPS measurements remaining in the same location
geo-spatial standard
Systematic errors:
Displaced from the standard
Definition of the Meteras 1/107 the distance between the
equator and the north pole- about the time of the French Revolution 1791- an effort to standardize units of measure- wrt “nature” Astronomers: Jean-Baptiste Delambre and Pierre Mechan
Earlier measurement by Eratosthenes ( 276-195BC) of circumference
f th th t ithi f % f t d t i h d
Latitude is 37 degrees, 52 minutes, 16 secs or 37.87 decimal degrees. Fraction of latitude north of the equator = 37.87/ 90 degrees=0.4208 Predict the Northing in UTM coordinates:
Mean radius of the “spherical” earth = 6 37 x 106meters of the earth to within a few % of current data using shadow
length in Alexandria during summer solstice
Mean radius of the spherical earth 6.37 x 10 meters Circumference = 2r=4.0x106meters= 40,000,036 m Equator to Pole = Circumference/4 = 1.0 0x107meters
Radio Waves
19 cm
AOR-W POR
Remember:
Wait until the hard drive indicator stops before doing anything Turn off back lighting out doors to save battery life
Turn off bell sounds to save battery
Take care of the computer, GPS, pen and spare battery now in your charge- no room for a “shaggy dog story”
While traveling, Put PC’s in box case or in your own personal care in your lap
When leaving lab, make sure zippers are
closed after changing batteries so they don’t fall out
th d
on the ground
Save your work using red Save Button Use red Exit button to exit GeoMapper
Lockers: Each night:
Hang computer with screen towards the right on the hook on the right side of your locker
Partially unzip the case and plug in the power cord and check display to make sure it is in fact on charge
Plug extra battery onto the charger nearby on the desk top
Put your padlock through the hole from the right side Make sure that the locker door is closed securely
Liability Acceptance and Honor Code Agreement For Use of Pen Computers
Care of pen computer: Using portable pen computers in the lab and the field require that they be treated with respect and handled accordingly at all times even when driving to and from the field They are fragile all times even when driving to and from the field. They are fragile
instruments. They cannot be just put in the back of the truck, but should be carried by each student or put in the box provided being careful that no damage occurs to the screens. Once a computer is assigned to a
student team it is under their care until it is signed back in at the end of the course. Lockers are provided for each computer and a key is assigned to each student. After returning from the field, a used battery assigned to each student. After returning from the field, a used battery must be returned to the battery charger docking station and the computer
hung on the right side of the locker and its charging cord plugged in so the main battery is charged ready for the next use. To plug in the cord, the black field case is unzipped partially.
Be careful to zip up the case
so the computer does not fall out when leaving for the field. Be careful when you take the computer from the locker not to drop the computer. Besides the mapping file with your name on it and assigned to you below, No other files or programs can be put on this computer.
Student mapping files are propriety to the students making them and to Stude t app g es a e p op ety to t e stude ts a g t e a d to the instructor and should not be open by any other student. All existing map files, quizzes, and past report are off limits to all EPS 101/271 students. All sources of information must be acknowledged in your reference list of your report. The PC tablets computers are to be used only for this class as designated by the instructor. Room 345 is to be used only with the Professor’s permission.
I accept financial liability to cover the costs of repairs of the pen
computer assigned to me either because of negligence or accidents while under my care and agree to all conditions above. A lost computer is $ 2435, Battery is $ 178, case $ 128, stylus $ 30 and a GPS unit is $ 78. Damaged computers can cost as much as $ 350 to repair and will mean mapping on paper while the tablet is being repaired.
I accept financial responsibility for the pen computer and promise to obey the use codes above Computer Open berkhills map and Save As:
# Signature # 1 Student # 2 Map file name be2010flfl
2 ____________________ ______________________ ______________________________ 3 ____________________ ______________________ ______________________________ 4 ____________________ ______________________ ______________________________ 5 ____________________ ______________________ ______________________________ 6 ____________________ ______________________ ______________________________ 7 ____________________ ______________________ ______________________________ I do not accept financial responsibility and will use only the map board
Name:
_____________________ _____________________ _____________________
Prepare the base map each team will use:
Go to lockers and bring pen tablet back to this room Teams of 2 people- share one PC tablet (10 PC’s in all) Each tablet will be with a green mapping vest
Do this together in unison Open GeoMapper
Go to EPS 101 directory Green Start Mapping button Wait until you see the GeoMapper icon interface Blue Select Base Button
Vector box, select “berk” file OK then Yes twice
File Save As: be10flf.pts
where f = first initial; l =1st letter of last name More …..
Mapping in the Siesta Valley Formation using DM Systems
Purpose:
Use of GPS to map lacustrine beds lacustrine beds
Meet up at Strawberry Canyon
Take pen tablet Extra battery