GPS World, April 2016

SYSTEM SYSTEMS OF LightSquared Testing the Sequel Use of a defined change in the noise floor 1 dB provides a readily identifiable and predictable metric that all interested parties can take into account now and in the future IRNSS Nears Completion GLONASS Special K APRIL 2016 WWW GPSWORLD COM GPS WORLD 11 T he U S Department of Transportation DoT announced in March that testing for the Adjacent Band Compat i bi l i ty ABC Assessment will start in April Conducted at the U S Army Research Laboratory White Sands Missile Range the tests seek to determine power limits for spectrum bands near the GPS L1 signal Later tests will focus on potential interference with the L5 signal and frequencies of other satellite navigation constellations In 2012 after tests at that time demonstrated that the proposed LightSquared network of groundbased transmitters would interfere with GPS the Federal Communications Commis s i on FCC d e n i ed LightSquareds petit ion while authorizing further tests never conducted until now Testing will take place across a 200 megahertz band spanning 157542 MHz GPS L1 An interference tolerance mask is defined as the point at which the interference test signal power level causes a one decibel degradation in the signal to noise ratio GPS and GNSS receivers designed for aviation noncertified cellular general location navigation precision timing network and space based application will be run through the high powered gauntlet The Depar tment request s voluntary participation in this study by any interested GPS GNSS device manufacturers or other parties whose products incorporate GPS GNSS devices the DOT said Ligado the renamed LightSquared company from 2012 came to separate legal settlements with GPS companies Garmin Trimble and John Deere in 2015 the terms have not been disclosed Use of a defined change in the noise floor 1 dB wrote a Deere attorney to the FCC provides a readily identifiable and predictable metric that all interested parties can take into account now and in the future T he sixth satellite in the Indian Regional Navigation Satellite System IRNSS launched on March 10 and all subsequent orbital steps proceeded according to plan IRNSS 1F was injected to an elliptical orbit very close to its intended final orbit The Indian Space Research Organizations ISROs Master Control Facility MCF at Hassan Karnataka took over the control of the satellite Maneuvers will position the satellite in geostationary orbit at 325 degrees East longitude IRNSS 1F is the sixth of the seven satellites constituting the space segment of the Indian regional system All five previosly launched satellites are functioning satisfactorily from their designated orbital positions A complete constellation of seven is planned for the second half of this year The first IRNSS position fix announced by ISRO providing longitude latitude and altitude took place in April 2015 Since then position fixes using stand alone IRNSS receivers have obtained accuracies of better than 15 meters for a minimum of 18 hours in a day over India The regional SBAS broadcasts navigation signals in the L5 and S band frequencies and computes user position solutions for a restricted service and a standard positioning service A new generation Russian GLONASS K satellite began regular broadcasts on Feb 15 The K model line transmits five navigation signals in the GLONASS L1 L2 and L3 bands and carries a COSPAS SARSAT payload for international search and rescue K satellites will gradually replace t h e GLONASS M generation bringing with them new CDMA civil signals compatible with GPS and Galileo Eleven new K satellites will take to space starting in 2018 using European and Chinese components as well as those being developed under an accelerated Russian import substitution program