ON-BOARD GCPS MATCHING WITH IMPROVED TRIPLET LOSS FUNCTION

Abstract

Intelligent remote sensing satellite system is an important direction to solve the problem of intelligent processing on-board. It can realize the real-time on-board intelligent processing of important targets. The accuracy of geometric positioning information is the basis for subsequent intelligent processing. Therefore, this paper corrects the positioning information by GCPs (Ground Control Points) matching on-board. Considering the limited storage and computing performance of satellites, this paper designs a lightweight GCPs deep feature extraction convolutional neural network based on MobileNetV2 as feature extraction model, and trains this network with an improved triplet loss function. The Songshan calibration field images constructed by Wuhan University was used as the GCPs image, and 30,399 image patches were extracted and embedded as GCPs feature library. The size of the GCPs library is a size of 15.3M, and size of the lightweight depth feature extraction model is 9.83M, which can be pre-stored on the satellite for positioning with GCPs matching on-board. In addition, this paper tested feature extraction performance on an embedded device Nvidia Jeston Xavier which simulates the performance of the device on the satellite. At Xavier 30W max power consumption model, a single frame takes 0.005 seconds, and under Xavier 15W power consumption model, a single frame takes 0.009 seconds. At 10W power consumption model, a single frame takes 0.018 seconds, which can meet the performance requirements on the satellite. In addition, the experiments in this paper show that the positioning accuracy is within 30 meters. The work done in this paper will be experimented on the Luojia-3-01 intelligent remote sensing satellite.