Low power, light weight, anti-jamming GPS antenna

A method for estimating a covariance matrix of a received RF signal including a global navigation satellite system portion and an interference portion, the method comprising:

• (A) providing, by a microcontroller, first digital control commands to control numerically controlled attenuators associated with a plurality of paths to attenuate the received RF signal;
• (B) providing, by the microcontroller, second digital control commands to control numerically controlled phase shifters to set a phase shift of the numerically controlled phase shifters wherein the numerically controlled phase shifters are included in the plurality of paths associated with the numerically controlled attenuators;
• (C) estimating diagonal elements of a covariance matrix of the received RF signal from multiple antennae by setting a first attenuation of a first path of interest of the plurality of paths to minimum and a second attenuation of all other paths of the plurality of paths to maximum;
• (D) receiving, by the microcontroller from an analog power detector, a first power measurement;
• and
• (E) estimating nondiagonal elements of the covariance matrix of the received RF signal by the steps of:
• (i) setting attenuation of two paths of the plurality of paths associated with a covariance matrix element of interest to minimum attenuation and setting all other paths of the plurality of paths to maximum attenuation;
• (ii) setting a respective phase shift of the two paths associated with the covariance matrix element of interest to zero degrees;
• (iii) receiving, by the microcontroller from the analog power detector, a second power measurement;
• (iv) setting phase shift of one of the two paths associated with the covariance matrix element of interest to 90 degrees while keeping attenuation constant;
• (v) receiving, by the microcontroller from the analog power detector, a third power measurement, and
• (vi) calculating, using the first, second, and third power measurements, the nondiagonal elements of the covariance matrix.