ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / For the final evaluation of a GPS attitude determination algorithm, it was determined its true performance in terms of its accuracy, reliability and dynamic response. To accomplish that, a flight test campaign was carried out to validate the attitude determination algorithm. In this phase, the measured aircraft attitude was compared to a reference attitude, to allow the determination of the errors. The system was built using non-dedicated THALES Z-FX airborne GPS receivers and a complete Flight Tests Instrumentation (FTI) System. Each GPS receiver operates synchronized with its internal time base. The FTI measurements are synchronized to an IRIG-B time base. All time bases have their own random walk characteristic. To avoid C/A code ambiguity, when its internal time base approaches ±1ms error from the GPS time, its clock is then corrected causing time and phase observables discontinuities. A multiple time base synchronization process was developed to correlate GPS and FTI data. The results are presented and the residual errors were considered acceptable. These data allowed the determination of the performance and accuracy of the GPS attitude determination algorithm. The tests profiles are fully compliant with the Federal Aviation Administration (FAA) Advisory Circular (AC) 25-7A.

ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV / A field programmable gate array (FPGA) is used to decode Inter-Range Instrumentation Group (IRIG) time code for a PC-based Time-Space-Position Information (TSPI) acquisition. The FPGA architecture can latch time via an external event trigger or a programmable periodic internal event. By syncing time with an external IRIG Group Type B (IRIG-B) signal and using an 8 megahertz (MHz) internal clock, captured time has 125 nanosecond (ns) precision. A Range Instrumentation Control System (RICS) application utilizing the FPGA design to capture IRIG time is presented and test results show matching time accuracy when compared to commercial IRIG time capture hardware components.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Airborne instrumentation used during flight tests is being installed and maintained in a unique way by operational bomber testers from the Air Force’s 53d Wing. The ability of the flight test community to test on operational aircraft has always been somewhat curtailed by the need for advanced forms of instrumentation. Operational fighter flight test squadrons have aircraft assigned to them, which they modify on as needed basis, much the same as developmental testers. However, bomber operational test units must use operational aircraft to accomplish their mission as there are no bombers in the Air Force’s Air Combat Command (ACC) specifically set aside for operational tests. During test missions, these units borrow aircraft from operational bomb wings, and then return them to service with the bomb wing after testing is complete. Yet, the requirement for instrumentation on these test missions is not much different than that of developmental testers. The weapon system engineer’s typically require Mil-Std-1553, video, telemetry, and Global Positioning System (GPS) Time-Space-Position-Information airborne receiver recordings. In addition, this data must be synchronized with an IRIG-B time code source, and recorded with the same precision as the data gathered during development test and evaluation (DT&E). As a result, several techniques have been developed, and instrumentation systems designed for these operational test units to incorporate instrumentation on operational aircraft. Several factors hamper the usual modification process in place at bases such as Edwards AFB and Eglin AFB. Primary among these is the requirement to maintain the aircraft in an operational configuration, and still meet all of the modification design safety criteria placed on the design team by the aircraft’s single manager. Secondary to the list of restrictions is modification time. Aircraft resources are stretched quite thin when one considers all of the bomb wing’s operational commitments. When they must release an aircraft for test missions, the testers must insure that schedule impacts are minimal. Therefore, these systems must install and de-install within one to two days and be completely portable. Placing holes in existing structures or adding new permanent structure is unacceptable. In addition, these aircraft must be capable of returning to combat ready status at any time. This paper centers on the B-52 bomber, and the active aircraft temporary modifications under control of the 49th Test Squadron (49 TESTS) at Barksdale AFB in Louisiana. The B-52 presents unique design challenges all its own, in addition to the general restrictions already mentioned. This paper will present the options that the 49 TESTS has successfully used to overcome the aforementioned restrictions, and provide an appropriate level of specialized instrumentation for its data collection requirements.