Dynamic Time Warping (DTW) based GNSS Interference Detection Algorithm for Edge Devices
Wilbur Myrick, ENSCO, Inc Daniel Goff, ENSCO, Inc Stanley Radzevicius, ENSCO, Inc
Edge computing combines low power consumption with high compute capability for edge devices needing robust processing and recognition capability. This paper explores developing a Dynamic Time Warping (DTW) GNSS interference detection algorithm designed to operate on an ultra-low power, high-performance multicore microcontroller for edge devices. This multicore microcontroller for edge devices combines a GNSS receiver with a digital signal processing (DSP) engine that allows researchers to develop, integrate, and test advanced GNSS interference detection algorithms for edge devices. A land vehicle is used as a mobile data collection platform to support the development of the DTW based GNSS interference detection algorithm. Research results of the DTW based GNSS interference detection algorithm leveraging GNSS signal strength (C/No) measurements are discussed.
In 2018, Sony introduced the GNSS based Spresense SoC to support the market need of power efficient IoT tracking devices. These IoT devices could be used to provide inexpensive GNSS interference monitoring capabilities in areas of interference potentially caused by illegal jammers if there is access to the raw measurements generated by the GNSS chipset. We obtained a development board associated with this Spresense microcontroller module and developed software to access the raw GNSS measurements to explore the feasibility of implementing a Dynamic Time Warping (DTW) based interference detection algorithm to explore leveraging the Spresense SoC module as a low-cost GNSS interference monitoring device. The objective of this research is to explore the performance and feasibility of implementing a DTW based GNSS interference detection algorithm based on this low-cost multiprocessor microcontroller. We explore the feasibility of leveraging the DTW algorithm and present results for detecting GNSS interference events.
We demonstrate a DTW based GNSS interference detection algorithm versus Euclidean norm algorithm in a mobile collection environment leveraging the Sony Spresense microcontroller. Our research illustrates how an Edge IoT microcontroller with a built-in GNSS receiver can be utilized as a portable GNSS interference collection system to monitor potential interfering sources in the GNSS band. Future research will determine the feasibility of implementing the DTW algorithm on the Sony Spresense microcontroller leveraging its DSP architecture. This would fully demonstrate a low size, weight, and power (SWaP) GNSS interference detection and monitoring capability for edge devices.