Reverse-ephemeris method for determining position, attitude, and time
First Claim
1. A method to calculate position of a platform comprising the steps of:
- using a detection and ranging system coupled to the platform to transmit a signal to a space object having a known ephemeris;
receiving, at the detection and ranging system, a reflected signal from the space object, wherein the reflected signal is the transmitted signal reflected off of the space object;
determining a range of the platform from the space object using a time delay between transmission of the signal and receipt of the reflected signal;
determining a range-rate using a Doppler frequency shift between the transmission of the signal and the receipt of the reflected signal;
calculating a position fix of the platform using the determined range, the determined range-rate, an altitude of the platform, and the known ephemeris of the space object.
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Abstract
A method to calculate position of a platform using a detection and ranging system coupled to the platform to transmit a signal to space object having a known ephemeris. The detection and ranging system receives the reflected signal from the space object. Taking the range of the platform from the space object using a time delay between transmission of the signal and receipt of the reflected signal and the range-rate using a Doppler frequency shift between the transmission of the signal and the receipt of the reflected signal makes it possible to calculate a position fix of the platform using the determined range, the determined range-rate, an altitude of the platform, and the known ephemeris of the space object.
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Citations
6 Claims
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1. A method to calculate position of a platform comprising the steps of:
using a detection and ranging system coupled to the platform to transmit a signal to a space object having a known ephemeris; receiving, at the detection and ranging system, a reflected signal from the space object, wherein the reflected signal is the transmitted signal reflected off of the space object; determining a range of the platform from the space object using a time delay between transmission of the signal and receipt of the reflected signal; determining a range-rate using a Doppler frequency shift between the transmission of the signal and the receipt of the reflected signal; calculating a position fix of the platform using the determined range, the determined range-rate, an altitude of the platform, and the known ephemeris of the space object. - View Dependent Claims (2, 3, 4, 5, 6)
Specification