ATP-3-09-12 Field Artillery Counterfire and Weapons Locating Radar Operations Download
Page 116 of 150
Appendix J J-2 ATP 3-09.12 26 October 2021 TRAILER POWER DISTRIBUTION UNIT J-4. The trailer power distribution unit is a 400 hertz, 60 kilowatt generator, mounted on a M200A1 trailer. The prime mover tows the trailer. Based on the cable lengths the OCG can be placed 40 meters from the ATG. The PDG can be placed up to 30 meters from the ATG given the combined lengths of the prime power and ATG power cable. SITE REQUIREMENTS J-5. The technical aspects and characteristics of the AN/TPQ-36 determine the requirements for site selection. The section chief selects the actual WLR site from the general area for positioning established by the FAB, DIVARTY, or BN operations officer. These positions are recommended by the counterfire officer during the MDMP. The technical considerations for site selection and emplacement include: Slope. Area in front of the antenna. Screening crest. Masking. Aspect angle. Electronic line of sight. Track volume. Proximity of other WLRs. Cable lengths. SLOPE J-6. Slope is an important consideration for the proper positioning of the AN/TPQ-36. Safety is a consideration when positioning the ATG. The slope of the terrain cannot exceed 7 degrees (120 mils) to ensure proper leveling of the ATG. The ATG will not operate properly without leveling. Some slope is advantageous and enhances AN/TPQ-36 functioning. Slope also provides drainage to the site that can help prevent components from becoming stuck during periods of heavy or continuous rainfall. AREA IN FRONT OF THE WEAPONS LOCATING RADAR J-7. The area in front of the ATG should be clear of foliage that extends above the bottom of the antenna. AN/TPQ-36 signals can be attenuated by more than 1 decibel per meter if operating within heavy foliage. A few meters of foliage can severely reduce the detection effectiveness. A clear area in front of the ATG minimizes attenuation of the radar beam. This area should extend 200-300 meters in front of the ATG. The ideal site will have a clear area in front of the ATG that has a gentle downward slope for approximately 200- 300 meters and then gradually rises up to the screening crest. The downward slope reduces multipath errors. Multipath errors are created when the computer controlled signal processor transmits or receive signals traveling by more than one path during detection. SCREENING CREST J-8. A screening crest increases the survivability of the AN/TPQ-36 by serving as a defense against enemy observation (visual and infrared), direct fire, and electronic countermeasures. The screening crest also helps attenuate sound. Ideally, the screening crest should be in friendly territory and located approximately 1000 meters in front of the ATG, perpendicular to the AN/TPQ-36 azimuth to center sector. When possible utilize a dual screening crest. The first screening crest should be approximately 250 meters and the second screening crest at 1000 meters from the AN/TPQ-36 site. J-9. The vertical angle to the screening crest should be between 15-30 mils for the AN/TPQ-36. The optimum vertical angle is 10 mils. The difference between the highest and lowest points on the screening crest should not exceed 30 mils for the AN/TPQ-36. A difference of more than 30 mils reduces the ability of the AN/TPQ-36 to produce enough track volume to compute a POO or POI. The vertical angle between the ATG and the top of the screening crest is called a mask angle.