ATP-3-09-12 Field Artillery Counterfire and Weapons Locating Radar Operations Download
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AN/TPQ-53 Weapons Locating Radar System Characteristics and Employment 26 October 2021 ATP 3-09.12 H-15 H-50. The 90 Degree long range optimized mode is derived from the 90 degree normal mode. This mode has been modified in order to locate 240mm rockets at 60km. This mode provides improved performance over 90° mode from 12-60km while retaining some very short range capability in to 500 meters. H-51. The 90 Degree 107mm rocket mode was designed to enable performance against long range 107mm rockets out to 50km. It is derived from the 90 degree normal mode with all but the long range search fences removed, and all detections inside of 25km suppressed. This mode is intended to be operated over a 1067 mil (60 degree) sector when the threat is specifically very long range 107mm (light) rockets. H-52. The 360 degree search mode allows coverage of 360 degrees or 6400 mils by rotating the antenna array at a rate of 30 RPMs. Through beam steering, a beam stack at both 30 degrees to the left and right of the main beam stack enables electronic scanning of the entire search sector covering 21 degrees of elevation three times in each mechanical rotation. H-53. The 360 degree weather mode was designed to provide 360 degrees performance from 3-20km while operating in heavy rain clutter. This mode improves Doppler resolution to reduce the effects of clutter, but to offset this improvement; it reduces the search elevation coverage of the 360 degree normal mode. To counteract the reduction in search elevation coverage, this mode adds the ability to dynamically place beams on tracks of interest, maintaining performance while in rain clutter in a 6400 mil (360 degree) mode. TARGET CLASSIFICATION H-54. The AN/TPQ-53 classifies acquisitions as three distinct target types: mortar, artillery, or rocket. The AN/TPQ-53 does not differentiate subtypes for these target types and defaults to unknown. The target classifications generated by the AN/TPQ-53 for transmission to AFATDS are mortar, artillery, and rocket unknowns. Of significant importance in target type classification for the AN/TPQ-53 system is the low datum plane. Estimates of target dynamics at launch are the primary discriminators used in the system software to determine the target type classification. This launch state is based on extrapolation of the target track to the low datum plane. As such, the low datum plane must match the true low point of the sector of operations as closely as possible. Significant mismatch in the low datum plane and the true gun height may cause the AN/TPQ-53 to misclassify the target, inducing accuracy errors, or possibly even failure to locate as the track may no longer appear to be a target of interest. PROBABILITY OF LOCATION H-55. The AN/TPQ-53 was designed to achieve at least 85% probability of location for all targets at the ranges listed in tables H-2 and H-3. Optimal operational mode selection based on priority threat intelligence ensures targets are located with the highest probability. AN/TPQ-53 FRIENDLY FIRE H-56. The AN/TPQ-53 does not have a dedicated friendly fire mode. Friendly fire missions can be executed while the system simultaneously performs its hostile weapon locating mission. The AN/TPQ-53 has the ability to perform friendly fire missions in both 90 degree modes and 360 degree modes. H-57. In the 90 degree mode, unlike the AN/TPQ-36 system, the AN/TPQ-53 can track weapons for friendly fire registration while simultaneously tracking hostile targets. The AN/TPQ-53 can register at all impact ranges between 3km and 40km. The AN/TPQ-53 can perform friendly fire registration in both 90 and 360 degree modes. H-58. When executing a friendly fire mission in 90 degree mode, the WLR sets up a horizontal "window" through which the projectile must pass. The window is referred to as the friendly fire search fence as shown in figure H-9. The narrowed search fence provides the best probability of detecting and tracking friendly rounds fired. The WLR tracks projectiles until it has enough data to predict the POI.