Accession Number : ADA256916


Title :   Real-Time Ionospheric Monitoring System Using the GPS


Descriptive Note : Technical rept.


Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB


Personal Author(s) : Coster, A J ; Gaposchkin, E M ; Thornton, L E


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a256916.pdf


Report Date : Aug 1992


Pagination or Media Count : 31


Abstract : In satellite tracking using ground-based radars, an estimate of the total electron content (TEC) along the path to the satellite is required to measure accurately the range of the satellite. This estimate is necessary because the radar wave travels at a slower speed as it propagates through the ionosphere. The range error Delta R that is introduced is dependent on the radar frequency f and on the TEC along the propagation path, and can be expressed by where Ne is the local electron density and R is the radar range. The TEC can vary significantly with the time of day, geomagnetic activity, and look direction. A real-time synoptic ionospheric monitoring system has been developed using data acquired from a T14100 Global Positioning System (GPS) receiver for use at the Millstone Hill satellite-tracking radar. The T14100 GPS receiver can track up to four GPS satellites at any one time. Each GPS satellite transmits signals at two different L-band frequencies: Ll (1575.42 MHz) and L2 (1227.6 MHz). ne TEC along the path to each satellite can be determined by combining both frequencies using the pseudorange and the integrated phase data. At Millstone, the TEC is measured every 3 s for each GPS satellite in view.


Descriptors :   *IONOSPHERE , *ELECTRON DENSITY , *GLOBAL POSITIONING SYSTEM , *RADAR TRACKING , FREQUENCY , PATHS , RADAR , RECEIVERS , ARTIFICIAL SATELLITES , TRACKS , L BAND , GROUND BASED , ERRORS , SIGNALS , ELECTRONS , TRACKING , DENSITY , MONITORING , REAL TIME


Subject Categories : Atmospheric Physics
      Navigation and Guidance
      Active & Passive Radar Detection & Equipment


Distribution Statement : APPROVED FOR PUBLIC RELEASE