The surveillance and verification test is a two-part test designed to determine the overall go or no-go status of the missile. The test is performed at the ammunition supply point (ASP) using the GMSTS. The surveillance and verification test is performed annually on approximately 20 percent of the missiles stored in the ASPs. It is also performed upon receipt of the M/LPAs at the ASPs and after the M/LPAs have been returned to the ASPs from the using units. The verification test ensures that the missile's electronics are functioning properly. The surveillance test verifies the inertial guidance unit (IGU) calibration. The two tests may be run independently or in conjunction with each other.
Pretest Operations
Prior to testing, the test personnel should review the M/LPA records for any previous deficiencies, verify the information on the M/LPA calibration label, and perform a self-test of the GMSTS.
Test Area Requirements. Prior to performing the surveillance and verification test, the M/LPA must be leveled to within ± four degrees in elevation and
Figure 7-14. GMSTS Power Supply Assembly.
roll. A compass-oriented reference line must also be established to within four degrees of true north. This reference line is used to orient the M/LPA to the north prior to testing. The latitude and longitude in degrees,
GMSTS Hookup. The GMSTS may be configured with either an AC or a DC external power source (figure 7-15). With an AC input, the DC power cable (71P1) is connected to J2 on the power supply assembly. CX-71P2 is connected to J6 on the test unit, and CX-71P3 is connected to J1 on the test unit.
The missile power cable (CX-70P1) connects to J7 on the test unit, with CX-70P2 connecting to J2 on the M/LPA. The SETCOM cable (CX-50P1) connects to J2 on the test unit, and CX-50P2 connects to J1 on the SETCOM. The AC primary power cable (CX-72P2) connects to J1 on the power supply assembly, and CX-72P1 connects to the external 110 VAC, 60 Hz power source. If a 220 VAC, 50 Hz power source is to be used, the AC power adapter (CA-76) connects to CX-72P1.
With a DC power input, the same hook-up configuration applies, except that the DC power cable (CX-71P1) connects to the external DC power source. Cable adapter CA-75 is used to adapt cable assembly CX-71P1 to a NATO slave receptacle configuration.
Test Procedures
The surveillance and verification test consists of the GMSTS initialization, the missile power-up sequence, the missile IBIT function, the load and purge function, and the surveillance test.
GMSTS Initialization. Upon completion of the GMSTS self-test, the surveillance and verification test is initiated when the operator selects the ATACMS test option through the SETCOM. Once the test is initiated, the operator enters the calendar date, the time of day and the part number and serial number of the M/LPA. The main M/LPA test program then verifies the M/LPA part number and serial number with the applications program version. If the part number and serial number match the applications program version, the main M/LPA test program then loads the applications program from bubble memory to operating RAM for execution. The applications program prompts the operator to connect the GMSTS to the M/LPA and then executes the following GMSTS-to-M/LPA interface checks.
The GMSTS verifies that the CX-70 cable is connected to M/LPA connector J2 (pins 50 and 51). If this connection cannot be verified, power application to the missile is inhibited.
The GMSTS checks the safe continuity loop (J2 pins 53 and 55) of the missile. If an open circuit is detected, the SETCOM will display MISSILE FAILURE to the operator.
The GMSTS checks the SAFE/ARM loop (J2 pins 53 and 54) of the missile. If a short circuit is detected, the SETCOM will display MISSILE FAILURE to the operator.
Missile Power-Up Sequence. The GMSTS connects four of the six external power channels to the missile.
These four power channels provide +24 VDC operating power to the on-board electronics. Upon the application of power, the missile electronics perform a power-up BIT consisting of a memory read/write and verify test, a resident program memory error check, and an interprocessor communication test.
A memory read/write and verify test is performed on each byte address in RAM of the guidance and navigation computer (GANC), the inertial sensor assembly computer (ISAC), and the control system electronics unit (CSEU) within the missile. This tests the processors' ability to write into and read out of the RAM modules.
A load verification is performed on the resident program memory area (EEPROM) of each processor. This is performed by summing horizontal and vertical totals (checksums) and adding these totals to complemented checksums obtained when the software load module was manufactured. The sum of the totals is then sent to the GMSTS. If the sum equals zero, a go status is indicated.
An interprocessor communication test is performed to check the communication interfaces between the three on-board processors.
At the completion of the power-up BIT, the GMSTS establishes communications with the missile by requesting the part number and serial number of the IGU and the CSEU within the missile. The missile configuration ID and software operational program version are then compared to that within the GMSTS. If the software versions do not match, the GMSTS loads the latest software version from the test unit to the missile.
Missile Internal Built in Test Function. The missile IBIT consists of the BIT functions of the IGU and the CSEU and a missile status report.
Prior to initiating the missile's IBIT function, the GMSTS applies two additional +24 VDC power channels to the missile. The additional power channels provide operating power to the CAS for operation of the control fin actuators.
The IBIT function is a comprehensive self-test of the missile's electronics assemblies. During the IBIT, a computer self-check is performed on the three on-board computers (the GANC, the ISAC, and the CSEU).
Artificial signals are applied to the accelerometers, and the results are checked. Artificial signals are also applied to the gyro pulse accumulator module, and the results are checked. Calibration processing checks, gyro and accelerometer temperature checks, power supply output checks, analog/digital (A/D) reference voltage checks, and a fin motion test are performed.
The missile status report indicates the status of various subassemblies within the missile. If a failure exists, the operator is prompted of a MISSILE FAILURE, and power is removed from the missile.
During the missile status report, the GMSTS verifies that the missile indicates it is NOT READY FOR LAUNCH, that the missile is NOT ON INTERNAL POWER, that the warhead SAFE/ARM/FIRE device is NOT ARMED, that the solid rocket motor (SRM) ARM/FIRE device is NOT ARMED, that the SRM is SAFE, that there is no internal communication failure, that the warhead SAFE ENABLE COMMAND IS NOT SENT, and that the CSEU indicates it is NOT IN FLIGHT MODE.
Upon completion of the IBIT, the results of this test along with the results of the 10 previous tests are stored in the missile's memory and then transmitted and logged into the test unit's memory. Also at this time, the two additional power channels that were used to power the CAS are removed from the missile.
Load and Purge Function. The load and purge function tests the IGU's ability to load and purge data in the classified data memory locations. Simulated classified data are sent to the missile, where they are downloaded and verified in the appropriate memory locations. Once downloaded, the data are purged at the operator's request.
If a failure occurs, the operator is prompted via the SETCOM.
Surveillance Test. With the test area requirements met and the M/LPA positioned so that the left side of the LP/C straddles the north compass-oriented reference line, the operator enters the initial conditions on the SETCOM keyboard. The initial conditions consist of the calendar date, the time of day, and the latitude, longitude, and altitude of the test site.
The GMSTS then performs an orientation verification to ensure that the M/LPA is level to within ± four degrees.
If the elevation or roll orientation is not correct, the operator is prompted of the incorrect orientation and
The initial conditions are sent to the missile, and the IGU enters the first of two surveillance calibration (S-CAL) modes. The operator is then prompted S-CAL 1 IN PROGRESS, APPROXIMATELY “#” MINUTES REMAINING.
The calibration gimbal in the IGU unlocks and rotates the inertial sensor assembly 360 degrees in twelve 30-degree increments. The test runs without operator intervention. If a failure is detected, the operator is prompted of the failure and the GMSTS initiates the missile power-down sequence. During the rotation, three new velocity parameters, three new altitude parameters, three new gyro biases, three new accelerometer biases, and three new accelerometer scale factors are determined.
Upon completion of S-CAL 1, the operator is prompted S-CAL 1 MODE COMPLETE, and the GMSTS commands the IGU to the rotation mode. During the rotation mode, the IGU begins supplying attitude data to the GMSTS. These data are decoded to display the azimuth orientation of the M/LPA to the operator on the SETCOM.
The operator is then prompted to rotate the M/LPA due east to within ± four degrees. During the rotation, the GMSTS maintains missile ground power to the missile and activates a 10-minute M/LPA rotation countdown timer. If the timer expires prior to the M/LPA being repositioned, all further testing is terminated.
Once the M/LPA is positioned east, the GMSTS performs an orientation verification to ensure that the M/LPA is level to within ± four degrees. If the elevation or roll orientation is not correct, the operator is-prompted of the incorrect orientation and instructed to level the M/LPA to within ± four degrees.
The GMSTS then transmits the initial conditions to the IGU, and the IGU enters the S-CAL 2 mode of operation.
The operator is prompted S-CAL 2 IN PROGRESS, APPROXIMATELY “#” MINUTES REMAINING. The calibration gimbal unlocks and rotates the inertial sensor assembly 360 degrees in twelve 30-degree increments to determine a second set of data.
Upon completion of S-CAL 2, the operator is prompted S-CAL 2 MODE COMPLETE. The GMSTS then requests the latest calibration results, along with up to 10 previous calibration results stored in the missile's memory. The new data are compared with the previous calibration results. A trend analysis is performed on the new data to determine their acceptability. If the data are acceptable, an ACCEPT S-CAL DATA command is sent to the missile, and the new data are added to the calibration parameter storage area in IGU memory along with the test date and time. If the data are rejected, the operator is prompted CAL DATA REJECTED and the missile is powered down.
Missile Maintenance
Maintenance on the ATACMS missile is performed only at the depot level. If the missile fails any part of the surveillance and verification test, it is routed back to the depot for repair. Maintenance on the missile will also include a depot-level calibration of the IGU. This is presently scheduled once every three years; however, due to the long-term stability of the ring laser gyros and the limited operating time expected, the interval is expected to be extended to once every ten years.
REVIEW EXERCISES Circle the letter of the correct answer to each question.
1. How many auxiliary processors that perform computational tasks does the electronics unit on the M270 launcher contain?
a. Two.
b. Three.
c. Four.
d. Five.
2. How often is the surveillance and verification test performed on the Missile/Launch Pod Assembly of the Deep Attack Missile System?
a. Monthly.
b. Quarterly.
c. Semiannually.
d. Annually.
3. What level of maintenance is authorized on the ATACMS missile?
a. Organizational.
b. Direct support.
c. General support.
d. Depot.
4. What is the purpose of relay K5 in the power distribution box on the M270 launcher?
a. It ensures that relay K3 in the EB is deenergized prior to energizing of the LDS.
b. It provides power to the FCS batteries.
c. It provides power from the FCS to the on-board weapons.
d. It directs output power to J6 and J7.
5. How many assemblies make up the guided missile system test set test unit?
a. Three.
b. Four.
c. Five.
d. Six.
6. How many alphanumeric characters are displayed on the set communicator?
a. 55.
b. 72.
c. 96.
d. 128.
Recheck your answers to the Review Exercises. When you are satisfied that you have answered every question to the best of your ability, check your answers against the Exercise Solutions. If you missed two or more questions, you should retake the entire lesson, paying particular attention to the areas in which your answers were incorrect.