Method and system for determining the phase and amplitude of a radio occultation signal
First Claim
1. A method for measuring phase and amplitude of a radio occultation signal, where the radio occultation signal is transmitted from a satellite-based transmitter to a receiver through an atmosphere, the method comprising the steps of:
- receiving the radio occultation signal;
down converting the received radio occultation signal based on at least one of a phase and frequency model to generate a down converted radio occultation signal;
low pass filtering said down converted radio occultation signal;
sampling in-phase and quadrature components of said down converted and filtered radio occultation signal; and
determining the phase and amplitude of the radio occultation signal based on said sampled in-phase and quadrature components.
1 Assignment
0 Petitions
Accused Products
Abstract
The present system for determining the phase and amplitude of a radio occultation signal modifies the traditional Open Loop tracking process to maximize the signal-to-noise ratio, minimize the sampling rate, and also preserve the structure of the radio occultation signals. A radio occultation system includes a transmitter system, a receiver system, and a post-processing system. The receiver system receives the radio signal that is transmitted by the transmitter system through the earth'"'"'s atmosphere, where it is occulted, and down converts the received radio occultation signal to generate a down converted signal based on a phase model that uses a refractivity climatology. The receiver system then low pass filters the down converted signal and samples the in-phase and quadrature components of the down converted and low pass filtered signal. The post-processing system receives the in-phase and quadrature components of the down converted and low pass filtered signal, determines the mean residual frequency, and performs additional down conversion of the sampled signal to eliminate aliasing. The post-processing system then re-samples the down converted signal at a higher sampling rate and calculates the accumulated phase and amplitude from the re-sampled signal.
-
Citations
22 Claims
-
1. A method for measuring phase and amplitude of a radio occultation signal, where the radio occultation signal is transmitted from a satellite-based transmitter to a receiver through an atmosphere, the method comprising the steps of:
-
receiving the radio occultation signal;
down converting the received radio occultation signal based on at least one of a phase and frequency model to generate a down converted radio occultation signal;
low pass filtering said down converted radio occultation signal;
sampling in-phase and quadrature components of said down converted and filtered radio occultation signal; and
determining the phase and amplitude of the radio occultation signal based on said sampled in-phase and quadrature components. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
-
-
12. A radio occultation system for measuring a phase and amplitude of a radio occultation signal, where the radio occultation signal is transmitted from a satellite-based transmitter to a receiver through an atmosphere, the radio occultation system comprising:
-
a receiver system comprising;
means for receiving the radio occultation signal;
means for down converting the radio occultation signal based on at least one of a phase and frequency model to generate a down converted radio occultation signal;
means for low pass filtering said down converted radio occultation signal;
means for sampling in-phase and quadrature components said down converted and filtered radio occultation signal; and
a post-processing system, responsive to said sampled in-phase and quadrature components of the radio occultation signal, for determining the accumulated phase and amplitude of the radio occultation signal.
-
Specification