Spectrum Savings from High Performance Network Recording and Playback Onboard the Test Article

Abstract

The Test Resource Management Center's (TRMC) Spectrum Efficient Technologies (SET) S&T program is sponsoring development of the Enhanced Query Data Recorder (EQDR), a network flight recorder that is intended to meet the future needs of the networked telemetry environment. EQDR is designed to support the "fetch" of recorded test data during a test without interrupting the ongoing recording of data from the test article vehicle network. The key benefits of the network data recorder as implemented in EQDR are increased flexibility and efficiency of test in an environment with increasing demands on spectrum available for telemetered data. EQDR enables retrieval of individual recorded parameters on an as-needed basis. Having the flexibility to send data only when it is required rather than throughout the duration of the test significantly increases the efficiency with which limited spectrum resources are used. EQDR enables parametric-level data retrieval, based not only on time interval and data source, but also on the content of the recorded data messages. EQDR enables selective, efficient retrieval of individual parameters using indexes derived from the actual values of recorded data. This paper describes the design of EQDR and the benefits of selective data storage and retrieval in the application of networked telemetry. In addition it describes the performance of the EQDR in terms of data recording and data retrieval rates when implemented on single board computers designed for use in the aeronautical test environment with size, weight, and power constraints.