Determining ionospheric time delays for global positioning system (GPS) receivers using multiple carrier frequencies

摘要

A method for determining atmospheric time delays Involves receiving at least two signals of different carrier frequencies 110a & 110b with an antenna 105, then amplifying each of the signals with a respective amplifier 150a & 150b to produce amplified signals 160a & 160b, digitizing each of the amplified signals with a respective analog to digital converter (ADC) 170a & 170b to produce digital signals 180a & 180b, then correlating each of the digital signals with a code using a respective correlator 190a & 190b to determine the time group delay differential between the signals, then calculating, with at least one processor, the time group delay coefficient of the signals by using the time group delay differential. The time group delay coefficient is then used to correct for the atmospheric time delays in the signals. The system may further comprises diplexing, filtering and down converting of the received signals.