The Global Positioning System (GPS) and Timing Branch at White Sands Missile Range (WSMR) operates GPS sensor equipment that collects Time Space Position Information (TSPI) for various Test platforms, both ground and airborne. The Branch is also responsible for operating and maintaining the Range Timing equipment that is GPS timing based.
The GPS sensors that are utilized include:
The ARDS System was developed by the Tri-Service Range Applications Joint Program Office (RAJPO) during the 1980's and early 1990's. The ARDS is a Multi-player/Mobile system which uses remote GPS relay sites to extend the range coverage of the systems under test. The ARDS system architecture consists of three unique segments: The Datalink Ground System (DLGS) Control Segment, the Master/Remote Ground Station (MRGS) datalink relay Segment, and the Participant Instrumentation Segment.
The ARDS Participant Instrumentation comes in two configurations, the AIM-9 Pod Configuration (AN/ARQ-52 (V) GPS Pod) and the Plate Configuration. The ARDS pods are primarily designed for aircraft instrumentation, mounted below the wings where the aircraft arsenal is normally carried. The AIM-9 Pod Configuration accommodates mounting on "fast movers" (F-14s, F-15s, F-16s, F-18s, GR1 Tornados, AV8Bs) and drone targets like QF-4s and F-4s. The Pod configuration also accommodates military helicopters (AH-1 Cobras and AH-64 Apaches). Plate Configurations support ground vehicles (tanks, humvees, ect.), helicopters, T-38's and are adaptable for other customized uses.
The main subsystems within the ARDS pods and plates are the on-board inertial measurement unit (IMU), a 10-channel (P/Y)-code compatible GPS receiver, a Datalink Transceiver (DLT) L-Band radio, a flash card recorder, an advanced Digital Interface Unit (ADIU) computer, and various power conditioning modules. Down linking of host vehicle 1553-type data is also possible using the optional Range Encryption Module (REM). The ARDS pods can be used in Real Time Casualty Assessment (RTCA) scenarios due to the fact that they can sense and record trigger pulls plus downlink weapon systems information from the host vehicle 1533 data bus.
Participant to Participant relaying capabilities allow the system to downlink or relay target information from those targets not within line-of-sight of a datalink relay station, thus enabling an extension of datalink coverage beyond that offered by the datalink relay stations alone. To date a single ARDS Control System has been used successfully to track up to 60 independent Participants as demonstrated during JCIET 2002.
The TSPI downlink and on-board recording data rate of the ARDS is variable at 0.1, 0.5, 1,2,5 and 10 Hz intervals. System accuracy is plus or minus 3 meters in x, y, and z (dynamic) and less than plus or minus 1 meter (static). The TSPI provided includes a Participant ID number along with navigation state data consisting of GPS time, position, velocity, acceleration, attitude, and attitude rates. The TSPI solution is based upon coupled GPS/IMU measurements using either precise encrypted (P/Y)-code or coarse acquisition (C/A)-code. The data output is in WGS-84, earth centered-earth fixed (ECEF) format.
The GPS Small Box configuration, also known as the ARDS Lite, supports: ground vehicles (tanks, humvees, ect.) and most military helicopters (including HIP and HIND). The configuration is also an adaptable small package for drone, cruise missiles and drone targets like the MQM-107 and BQM-74. Like the ARDS, the ARDS lite also provided TSPI utilizing the coarse acquisition (C/A) code of the GPS; with accuracies identical to that of the ARDS.