iPCM Telemetry System

Abstract

The execution of experimental Flight Test Campaign (FTC) provides all information required for the aircraft development, operation and certification. Typically the execution of a FTC encompasses three major systems as follows: Flight Test Instrumentation System (FTI) that is basically a measurement system; Real-Time Telemetry Link (RTL); and Ground Telemetry System (GTS). At the early days, for the development of small aircrafts (i.e. Fighter), the primary source for FTI data was provided by the RTL due to inherent limitations of the open reel airborne data recorders (i.e. media and size), operating under high-dynamics condition. Nowadays with the introduction of solid-state data recording devices, data integrity and reliability is no longer an issue. At the ITC 2010 Blue Ribbon Panel, Mr. Thomas Beard, the executive Director of the Air Force Flight Test Center in Edwards Air Force Base emphasized the need to reduce refly and to improve FTC efficiency. Such statement imposes a new paradigm in Telemetry, which is to improve RTL integrity and reliability level equivalent to the solid-state data recording devices. Therefore the Telemetry community will be able to execute test point validation for refly reduction and quasi realtime data reduction analysis for efficiency improvement. The major solutions that address such issue are Spatial Diversity (SD) architectures and the iNet. The SD solution requires multiple antenna system (which is very expensive) that could still produce ineffective results at high-dynamics test points (e.g. Spin). At the beginning the iNet consortium proposed the usage of TCP protocol for data transmission. Problems associated with TCP limitations such as data latency and overhead lead to the usage of UDP protocol that does not guarantee the packet delivery. To properly address these issues the IPEV R&D group proposes the iPCM Telemetry architecture to be used as RTL. The iPCM uses hybrid architecture for data transmission taking the advantage of legacy digital transmitters combined with iNet-based transceivers to retrieve missing data. The development and the evaluation of iPCM architecture will be executed as a PhD Thesis in ITA University. The expected performance and benefits of iPCM are presented and discussed.