Dr. Sanjeev Gunawardena

Today Global Navigation Satellite Systems (GNSS), of which the US Global Positioning System (GPS) is a part, have become the world's de facto system-of-systems for positioning navigation and timing. The signals received from GNSS satellites are typically about a thousand times less than thermal noise. Therefore, they are vulnerable to all sorts of channel effects such as interference.

A GPS receiver works by correlating the received signal with a locally-generated replica. It must first synchronize itself with the signal in a process called acquisition. It then transitions over to a process known as tracking where it steers its replica to follow the dynamics of the signal. It then uses the replica to compute the necessary range measurements to the satellites. Tracking is done by using just three correlation points: Early, Prompt, and Late. Using the analogy of driving a car, this is like steering while looking at the road through a narrow tube. If a GPS receiver were to have more observability, this increased situational awareness would allow it to do a much better job of tracking the signal and not get easily thrown off by channel effects. Enabling this capability however comes at the cost of increased complexity and power consumption.

This talk will introduce the attendee to a super-resolution processing technique known as Chip-Shape processing. This enables unprecedented situational awareness with reasonable efficiency. The talk will give an overview of the algorithm and describe case studies where is it proving to be extremely useful for high-fidelity GNSS signal monitoring. Chip-Shape processing may have utility in other areas where the observability of minute signal characteristics is desired.

Dr. Sanjeev Gunawardena

Biography: