Ground system adds more bandwidth to cluttered skies

Published May 11, 2010
By Kenji Thuloweit
95th Air Base Wing Public Affairs

EDWARDS AIR FORCE BASE, Calif. -- The installation of a first-of-its-kind aeronautical telemetry ground system here is making way for improved aircraft communication in skies already jumbled by frequencies from cell phones and satellite television.

This technology, which expands communications capability between aircraft and ground-based people and equipment, was installed at the U.S. Air Force Test Pilot School.

"Due to technological advances and the increase in civilian use of various frequencies, some of which happen to be the same frequencies we use, there has been a need to expand our range of frequencies for flight testing," said John Ward, Test Management Group and Telemetry Systems Integration and Support program manager.

Telemetry is a technology that allows remote measurement and reporting of information and how data from an aircraft is transferred to engineers on the ground to assess the aircraft's performance.

The TSIS program, in collaboration with the Test Pilot School, has installed the new aeronautical telemetry ground system, which is capable of acquiring airborne telemetry data in the L-, S- and now C-band frequency ranges. The system replaces an older ground telemetry system, which was capable of receiving telemetry only in the L and S ranges.

"Air-to-ground telemetry has always been conducted in the 1435-1525 megahertz (L-band) and 2200-2395 megahertz (S-band) frequency ranges," said Mr. Ward. "However, as we test aircraft with greater technology advancements, more telemetry bandwidth use is inevitable and this new tri-band telemetry capability will expand the range of available telemetry frequencies into the 4 gigahertz and 5 gigahertz ranges (C-band)."

The additional frequencies added will benefit both the surrounding community and the different squadrons on base by relaxing the encroachment of frequencies used by civilians and other squadrons.

"You may have emergency response companies and cell phone companies all desiring to use more and more frequencies, and that could cause congestion in the frequencies we use here for flight tests," Mr. Ward said. "Part of our goal is to help accommodate the increase by adding more frequencies that will allow us to conduct flight tests while at the same time allowing civilians to continue using our frequencies."

Mr. Ward says this new tri-band telemetry capability with the C-band receiver is likely the first of its kind in the world. The C-band installation occurred much earlier than expected because of a unique collaboration between the TSIS program office, TPS leadership, the 412th Test Wing and the contracting office. The TPS' flexibility in scheduling, small number of aircraft to equip and working relationship with the different offices were big factors in setting up the system ahead of schedule.

The new C-band at the TPS will help the school a great deal because, with numerous test squadrons at Edwards, the fight for frequencies can be challenging.

"Being the first to get ground level C-band is a plus because we're always competing for bandwidth with the rest of the base and we have one of the lowest priorities," said Steve Connor, TPS Lead Telemetry and Data Acquisition engineer. "To be able to go full C-band is going to work out perfectly for TPS."

Some acceptance testing still remains for the TPS ground systems. Early testing has been very encouraging and full initial operating capability is expected by July. The TSIS program is a five-year improvement and modernization program to upgrade the entire Air Force Flight Test Center ground and airborne telemetry capability.