초록 ▼

Method and apparatus are disclosed for accurately determining position from GPS satellites and received on a ship using C/A code group delay observable TAU, 308 fo implicit carrier phase observable PHI, L1 band implicit fo carrier residual phase observable PSIL1, and L2 band implicit fo carrier resi

Method and apparatus are disclosed for accurately determining position from GPS satellites and received on a ship using C/A code group delay observable TAU, 308 fo implicit carrier phase observable PHI, L1 band implicit fo carrier residual phase observable PSIL1, and L2 band implicit fo carrier residual phase observable PSIL2. A precise measurement of the group-phase delay range to each satellite is made based upon the L1 center frequency carrier phase. A correction for ionospheric effects is determined by simultaneous observation of the group delays of the wide bandwidth P code modulations in both the L1 and L2 bands. These group delays are determined by measuring the phases of carrier waves implicit in the spread-spectrum signals received in both bands. These carriers are reconstructed from both the L1 and L2 band signals from each satellite without using knowledge of the P code. The unknown biases in the L1 center frequency carrier phase range measurements are determined from simultaneous, pseudorange measurements, with time averaging. The instantaneous position of the ship may then be determined from the ranges so determined, with both the bias and the ion-spheric effects having been eliminated.

대표청구항 ▼

A method of determining range data from a composite of code modulated, overlapping spread spectrum signals received on a moving platform from a plurality of GPS satellites, comprising the steps of: developing estimates of the phase and delay of selected signals inherent in the composite; using the e

A method of determining range data from a composite of code modulated, overlapping spread spectrum signals received on a moving platform from a plurality of GPS satellites, comprising the steps of: developing estimates of the phase and delay of selected signals inherent in the composite; using the estimates to measure the phase and delay of the selected signals; updating the estimates in response to the measurements to derive phase and delay observations; and time averaging the observations to derive instantaneous platform range data.