RTCA’s Special Committee SC-159, Navigation Equipment Using the Global Navigation Satellite System (GNSS), and the Tactical Operations Committee (TOC) provided a review and comments on Ligado’s proposal for use of the GPS adjacent band for non-space, commercial applications. The proposal seeks to determine a site-by-site peak power output that ensures GPS reception for aircraft using certified avionics when they are 250 feet or more laterally from, or 30 feet or more above, a Ligado transmitter antenna. The Ligado proposal refers to the cylinders bounded 250 feet around and 30 feet above its antenna as a standoff cylinder
. SC-159 provided a technical review while the TOC provide an operational impact assessment.
SC-159’s Working Group 6 (WG-6), which focuses on GPS Interference, conducted the technical review. Comments from WG-6 were compiled and considered. Ligado, who participates with standing members on both SC-159 and WG-6, provided subject matter expertise, and in many cases, addressed WG-6 comments. On comments where consensus was not reached, the differing opinions were documented. The SC-159 report was approved during a virtual plenary on December 13, 2016, and the response was also presented to the Program Management Committee on December 15, 2016.
In parallel, the Tactical Operations Committee’s evaluation of the Ligado Proposal focused on the operational impact of the proposed standoff cylinders where access to GPS signals would not be guaranteed. A Task Group under the TOC held a series of discussions, also including Ligado as Subject Matter Experts. On December 13, 2016, the TOC approved a report which compiled operator’s comments and concerns regarding the proposal. The comments emphasized the impact of these cylinders on certain flight operations, particularly helicopters and unmanned vehicles. The TOC also commended Ligado for their engagement with the FAA and industry.
The SC-159 and TOC reviews are posted for the public on the RTCA website. Click HERE
for the TOC response. Click HERE
for the response from SC-159.