Keeping up with aircraft flying over the Gulf of Mexico is difficult if
not impossible in some instances. Now, that may change, with the help
of NASA and the Department of Transportation (DOT), which are testing a
new in-flight tracking system that is smaller, less costly and more
flexible than anything seen to date.

The Advanced Air Transportation Technologies (AATT) project led by
NASA’s Ames Research Center, Moffett Field, CA, and the DOT’s Volpe
National Transportation Systems Center, Cambridge, MA, are putting the
new system through its paces in Louisiana, offshore from Intercoastal
City. The current testing is designed to evaluate the operational
benefits of the system for fleet management in the Gulf.

The in-flight tracking system uses multiple small ground stations to
triangulate on an aircraft’s transponder signal, accurately determining
its position. “Radar coverage, particularly at low altitudes, is non-
existent over most of the Gulf of Mexico. The in-flight tracking system
will provide operators with precise aircraft position data. The data
from the tests will be evaluated by operators as a possible flight
tracking system,” said Mike Landis, AATT project manager at Ames.

The tracking system addresses many of the drawbacks of beacon radar
systems currently used for air traffic control. The system’s smaller
size, enhanced flexibility and reduced cost permit ground stations to
be placed in areas that are not feasible for beacon radar. This
includes remote areas, open water and sites with mountainous terrain.
These characteristics make the system particularly suitable for
tracking low-flying aircraft that cannot be monitored adequately by
standard radar systems.

“These tests will provide the Federal Aviation Administration (FAA)
with data they can use in determining how the new system compares with
radar,” Landis said. “We believe the new system may have significant
cost, size and flexibility advantages over currently available
systems,” he added.

The FAA and aviation users are evaluating the deployment of Automatic
Dependent Surveillance-Broadcast (ADS-B) which is based on all aircraft
transmitting their position reports (based on the Global Positioning
System) to surveillance systems in the area.

The tracking system is based on equipment originally developed by the
Sensis Corporation, DeWitt, NY, for the FAA’s Airport Surface Detection
Equipment, Mode X (ASDE-X) program. The role of the DOT is to manage
deployment of the system and conduct a technical assessment for NASA.