CPC G01S 13/89 (2013.01) [G01S 13/003 (2013.01); G01S 19/22 (2013.01)] | 20 Claims |
1. A system for tracking a carrier-to-noise ratio (C/N0) and a phase correction (Δϕ) of a reflected radio frequency (RF) carrier signal, comprising:
one or more processors that
receive a digital direct line-of-sight (DLOS) intermediate frequency (IF) signal of a DLOS component of an RF carrier signal transmitted by a transmitter located above the surface of the earth and a digital reflected IF signal of a reflected component of the carrier signal that is reflected from a specular point (SP) on the surface of the earth,
generate modeled reference signal parameters using the digital DLOS IF signal and known locations of one or more receiving antennas, the transmitter, and the SP,
generate a reference signal based on the modeled reference signal parameters and feedback of a previously estimated Δϕ,
correlate the reference signal with the digital reflected IF signal to produce in-phase (I) and quadrature-phase (Q) correlation results, and
calculate an estimated C/N0 and an estimated Δϕ for the digital reflected IF signal from the correlation results.
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