Accurate and Efficient Terrain Referenced Navigation Using Multiple Measurements by Flash LiDAR

Abstract

In this paper, the modified measurement equation of EKF based terrain referenced navigation (TRN) is proposed to apply the flash LiDAR measurement and the number of measurements is recommend to achieve maximum performance efficiently. The TRN estimates the vehicle position by comparing terrain information measured by radar altimeter (RA) with digital elevation map (DEM) values. Recently, various range sensors have been applied to improve TRN performance, especially light detection and ranging (LiDAR) sensor. The LiDAR is a highly precise range sensor and the flash LiDAR can measure a number of multiple range measurement simultaneously. Therefore it is expected that more accurate TRN performance can be obtained if the flash LiDAR is applied to the TRN. However, because the flash LiDAR measures slant range unlike the RA, the conventional TRN algorithm should be modified. In addition, using all measurements of the flash LiDAR is very inefficient because the estimate accuracy is almost saturated as the number of measurement increases so it is important to select the proper number of measurements. In this paper, the modified measurement equation of EKF based TRN algorithm is derived to use the slant range measurements from the flash LiDAR. Also, the effect of the number of measurements to the TRN performance is explained analytically and the number of measurement is proposed by simulation results. From the research, it is expected that accurate and efficient TRN using the flash LiDAR will be possible.