GPS World, September 2017

TAKING POSITION 8 GPS WORLD WWW GPSWORLD COM SEPTEMBER 2017 Q How can the safety security and full utility of GNSS applications be ensured while evolving to the best and most efficient use of limited and extremely valuable electromagnetic spectrum A 1 Agree that No electromagnetic spectrum use will be approved now or in the future that impacts GNSS PNT users a common mission statement essential to establishing trust 2 Determine how best to migrate todays GNSS PNT users to be more resilient to both interference and planned future adjacent band services 3 Provide detailed architectures network layouts and implementation plans for rollout of new adjacent band services compliant with 1 and supportive of 2 A We cannot ignore fielded legacy systems but neither can we chain ourselves to old technology and hinder progress Spectrum usage cannot be solved by less regulation but it can be with innovative regulatory ideas adhering to minimalist principles For example would a cash for clunkers program work to eliminate weak receivers from the field to enable more efficient spectrum use This is one of those situations where government involvement can spur an innovative solution MITCH NARINS PRINCIPAL CONSULTANT STRATEGIC SYNERGIES LLC JOHN FISCHER VP ADVANCED R D OROLIA SPECTRACOM BY Tracy Cozzens MANAGING EDITOR I had my special ISOcertified glasses ready Living in Oregon I wasnt about to miss the once in a lifetime chance to see a total eclipse of the sun On Aug 21 my family drove a few miles north to get into the path of totality which for us lasted about a minute It was definitely worth the field trip Besides regular folk like me experts in numerous fields turned their eyes and their instruments to the eclipse The National Center for Atmospheric Research took to the air with a Gulfstream V fitted out with sensors and equipment for atmospheric research The flight gathered data about the sun that cant be collected from the ground With better instruments than ever before for the first time scientists had the chance to observe the corona in the infrared spectrum which may provide insight into the suns magnetic fields Back on terra firma atmospheric scientists closely monitored changes in temperature and other weather e f fects The temperature dropped as much as 7 degrees in Crossville Tennessee reports the National Weather Service Scientists at zoos and aquariums across the country closely watched animal behavior during totality Species exhibiting unusual behavior included elephants hippos crocodiles and penguins As for GPS experts from the NASA Jet Propulsion Laboratory NASA HQ Earth Science Division and the University of New Brunswick kept a close eye on the event collecting data from GPS receivers and other ionospheric monitoring tools to better understand exactly how the ionosphere reacts to a total eclipse of the sun The scientists found a decrease in the number of free electrons in the part of the Earths ionosphere along the eclipse path where sunlight was temporarily blocked by the moon TEC total electron content time series from two continuously operating GPS monitoring stations near the path of totality show a small dip of about 2 TECU TEC units or so around 18 00 UTC on Aug 21 coincident with the timing of the eclipse The eclipse also affected WAAS real time correction data from geostationary satellites While study of the data continues its clear that GPS easily withstood the eclipse Go to gpsworld com 2017eclipse to learn more GPS Not Eclipsed by Solar Event