“The effects of LightSquared deployment would be far-reaching and potentially devastating to aviation,” the FAA wrote to the President’s Space-Based Positioning, Navigation and Timing (PNT) group in a report that was recently leaked to the media.
The GPS industry’s failure to comply with the Department of Defense’s receiver filtering standards is the root cause of potential interference issues involving LightSquared’s proposed broadband wireless network, the company has told the FCC.
Low-powered incoming GPS signals are allocated 1559-1610 MHz in the L-Band radio spectrum. The neighboring spectrum–from 1525-1559 Mhz–is allocated to other, equally low-powered, incoming satellite signals, such as Sky Terra’s. GPS receivers are open to signals above the blue line shown, but filter out signals below it, and require modification to accept Glonass.
Accord Technology’s NexNav mini GPS Waas Class Beta-1 sensor has been recognized by the FAA as meeting requirements outlined in Advisory Circular 20-165. The 20-165 requirements cover accuracy and other parameters that GPS sensors will need to meet standards for ADS-B operations. The FAA will require mandatory equipage with ADS-B out systems beginning in 2020.
LightSquared is running an advertising campaign in Washington, D.C., that includes prominent multiple advertisements along the platforms of downtown stations of the city’s Metro system serving Capitol Hill, FAA headquarters and other key government offices. Photo at left was taken this morning by an AIN staffer at L'Enfant Plaza Metro station.
With fresh evidence that LightSquared’s proposed wireless broadband network will cause widespread interference to GPS signal reception, principals of the industry Coalition to Save Our GPS went on the offensive today in a media conference call.
The ongoing controversy about whether LightSquared’s proposed network of 40,000 powerful ground-based stations transmitting high-speed Internet across the nation would interfere with adjacent GPS frequencies became more intense last month.
Following extensive reports of GPS interference, LightSquared announced last week that it would vacate its L-Band frequency adjacent to GPS and move to one further away to greatly reduce, but not eliminate, interference with satnav signals.
In May, Eurocopter’s proof-of-concept compound, the X3, reached 232 ktas, a speed it sustained during five minutes at 8,500 feet. It also demonstrated a rate of climb greater than 5,000 fpm. The crew flew pitch-up attitudes in the 30- to 50-degree range. Roll angles were taken to 80 degrees of bank.
A study released by the Save Our GPS Coalition warns of “serious repercussions for the U.S. economy” if LightSquared is allowed to broadcast 4G broadband signals that cause interference with GPS. According to the study, more than 3.3 million U.S.