http://hdl.handle.net/10150/578494 Fri, 05 Jun 2026 21:14:58 GMT 2026-06-05T21:14:58Z http://hdl.handle.net/10150/666533 International Telemetering Conference Proceedings, Volume 35 (1999) International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada Fri, 01 Oct 1999 00:00:00 GMT http://hdl.handle.net/10150/666533 1999-10-01T00:00:00Z http://hdl.handle.net/10150/608760 DOPPLER BANDWIDTH CHARACTERIZATION OF ARTM CHANNEL SOUNDING DATA Landon, David Data from ARTM channel sounding test flights is examined to characterize the dynamic channel behavior of aeronautical telemetry channels. The dynamic behavior is characterized using the Doppler power spectrum. The width of the Doppler power spectrum is the Doppler bandwidth of the channel which indicates the required bandwidth of adaptive detection techniques such as adaptive equalization, adaptive modulation, adaptive channel selection and adaptive error control coding. Data collected from ARTM Flight 11 suggest a Doppler bandwidth exceeding 6.7 Hz for the channel, but greater accuracy and resolution will only be possible with more data. International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada Fri, 01 Oct 1999 00:00:00 GMT http://hdl.handle.net/10150/608760 1999-10-01T00:00:00Z http://hdl.handle.net/10150/608747 ADVANCED RANGE TELEMETRY DYNAMIC MEASUREMENT LISTS Luten, Robert H.; Diekmann, Vernon A typical telemetry system for aircraft flight-testing transmits one or several data streams to the ground for real-time display and analysis, and also records the same stream onboard for later playback. During test operations, only a fraction of the available data is used at any given time for real-time display or analysis. More efficient use of the RF channel could be realized if only the data needed for the current test point is transmitted, rather than the entirety of the data. Intelligent selection of a subset of the data stream can provide large reductions in the required telemetry downlink bandwidth. As one of the Advanced Range Telemetry (ARTM) On-Board Data Management (OBDM) initiatives, a prototype on-board data selection subsystem is being developed and demonstrated. The demonstration utilizes COTS telemetry workstations to the maximum extent possible and includes “plug-in” data requestor, selection, and server components to implement the added DML functionality. A significant objective of the OBDM/DML project will be to validate RF channel models to help minimize the amount of flight-testing necessary to validate the DML concept. This paper will discuss the OBDM/DML architecture, integration of several custom components with the COTS portions of the ARTM “test bench”, and the current status of the OBDM/DML development and test program. International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada Fri, 01 Oct 1999 00:00:00 GMT http://hdl.handle.net/10150/608747 1999-10-01T00:00:00Z http://hdl.handle.net/10150/608746 ARTM CHANNEL SOUNDING RESULTS – AN INVESTIGATION OF FREQUENCY SELECTIVE FADING ON AERONAUTICAL TELEMETRY CHANNELS Rice, Michael; de Gaston, David; Davis, Adam; German, Gus; Bettwieser, Christian Initial results of wideband channel sounding experiments sponsored by the Advanced Range Telemetry (ARTM) program are presented. Data collected at Edwards EAFB during the Winter 1998-1999, are analyzed in the frequency domain to estimate the number, strength, and delays of the significant multipath reflections observed during the experiments. We observe that the channel is adequately modeled using two or three multipath reflections. The multipath fade events are correlated with recorded bit error rates and transmitter location to provide a comprehensive overview of the channel characteristics. Summaries from two test flights are included where it is seen that the 2- and 3-ray channel models provide excellent models for the data. In general, the 3-ray model captures the essential features of the multipath interference. In this model the first multipath is a strong specular reflection with relative amplitude greater than 0.5 and relative delay in the 30 to 70 ns range. The second multipath is a much weaker reflection with relative amplitude less than 0.5 and relative delay in the 175 to 325 ns range. International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada Fri, 01 Oct 1999 00:00:00 GMT http://hdl.handle.net/10150/608746 1999-10-01T00:00:00Z