Question

Kalman filter estimates ____

(a) time of arrival

(b) time difference of arrival

(c) propagation delay

(d) location

I have been asked this question in my homework.

My doubt is from Available Technologies for Cognitive Radio in chapter Cognitive Radio Basics of Cognitive Radio

Answer 1

Right option is (c) propagation delay

To elaborate: Kalman filter provides high resolution estimation of propagation delay from each satellite irrespective of their position. Kalman filter uses input from ground monitoring stations, space weather information, etc. The GPS receivers can estimate time with approximately 340 nanoseconds of jitter.