Precise Measurement Method for Ionospheric Total Electron Content Using Signals from GPS Satellites
COMMUNICATIONS RESEARCH LAB IBARAKI (JAPAN) KASHIWA SPACE RESEARCH CENTER
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Communications Research Laboratory CRL has developed a GPS codeless receiver called GTR-2 for measuring total electron content TEC along the line of sight to the GPS satellite by using the cross correlation amplitude of the received P-code signals carried by Ll1575.42MHz and 12 1227.6MHz. This equipment has the performance of uncertainty in the measurement of TEC of about 2 x 1016 electronsm2 when a 10 dBi gain antenna was used. To increase the measurement performance, CRL is planning an upper version of GTR-2 called GTR-3 which uses the phase information of the continuous signals obtained by making a cross correlation or multiplication of the received L1 and L2 P-code signals. BY using the difference of these measured phase values, we can estimate the ionospheric delay with the ambiguities of the periods of L1 L2 and L1 -L2 signals. As the periods of these signals are about 3 ns and 0.3 ns respectively, then this method has the possibility of TEC measurement with the uncertainty of 1 or 2 times of 1015 electronsm2 of TEC. Additionally to the precise measurement of TEC, this method has the ability of the precise measurement of the pseudo-range between the GPS satellite and the receiver for the precise positioning.
- Navigation and Guidance
- Nuclear Physics and Elementary Particle Physics