UAV Transponder May Hold Promise
By Mac McClellan, Editor-at-Large, EAA 747337
August 11, 2011 – Sagetech, a maker of electronics for unpiloted air vehicles (UAV), has built what is believed to be the world’s smallest transponder. The XP transponder from Sagetech is about the size of a business card and weighs just 105 grams. The tiny unit even contains an altitude encoder. And the company is nearing production of an XP transponder with Mode S extended squitter (ES) that could potentially meet the rules for ADS-B out.
The electronic worlds of UAV and regular airplanes are beginning to merge with even industry giants like Rockwell Collins working in the UAV field. Many UAVs are very small and low on power, so there is a premium on compact and efficient avionics to operate them. That is what is driving Sagetech to create the tiny transponders. And that same technology could be a breakthrough for light general aviation airplanes.
Sagetech has not yet announced prices for individual XP transponder purchases, and they do not yet have the certification that would allow the transponder to be installed in a manned airplane, but the company does promise a low price.
The ES function of the XP Mode S transponder is what holds promise for possible ADS-B approval. The ES portion of the transponder transmission can contain the position and velocity data needed to satisfy ADS-B out rules.
However, ADS-B is a complete system that combines the transponder with an approvable position source - almost certainly a WAAS-enabled GPS - and the FAA will only approve an entire system for a particular airplane. So far no equipment has full ADS-B out approval so it’s too early to say exactly what will comply with the rules, but having a transponder with ES is a crucial step on the path to meeting the ADS-B out requirement for 2020.
For more information on Sagetech and its incredibly small XP transponders, click here.