An Algorithm for Detection of Electromagnetic Interference in High Frequency Radar Range-Doppler Images Caused by LEDs

This paper focuses on the impacts that noise generated by the light emitting diodes (LED) have on high-frequency surface wave (HFSW) radars. Initially, the measurements of the electromagnetic interference caused by the LED lights were conducted in an anechoic chamber, in order to eliminate the influences of other interference sources. It was determined that the most significant interference in the HF range is generated between 6 and 12 MHz. Next, the HFSW radar measurements in real field conditions were conducted at an operating frequency of 6.7 MHz. The LED influence on the HFSW radar was analyzed using the range-Doppler (RD) images. A novel algorithm based on the image segmentation and image processing methods for the automatic detection of the LED noise in the HFSW radar RD image is proposed. The proposed algorithm was experimentally validated using the data obtained from the HFSW radar sites located in the Gulf of Guinea. It was concluded that the proposed algorithm is capable of identifying and eliminating the noise originating from the LEDs with a probability of 91%.