Performance analysis of landmark extraction by flight altitude for effective terrain relative navigation on Mars
- Paper number
IAC-24,A3,IP,68,x84950
- Author
Dr. Jae-In Kim, Korea Aerospace Research Institute (KARI), Korea, Republic of
- Coauthor
Mr. Sang-Wook KANG, Korea Aerospace Research Institute (KARI), Korea, Republic of
- Year
2024
- Abstract
To accurately land a Mars lander at a target point, the position of a descending lander should be determined in real-time. However, unlike on Earth, on Mars, global navigation satellite system (GNSS) assistance is not available, and real-time tracking from Earth antennas cannot be expected due to long distances. Terrain relative navigation is one of the ways to solve these problems, which has recently been considered an essential technology for planetary landers. Terrain relative navigation is a technology that estimates the position and attitude of a lander by comparing pre-constructed reference data with inertial measurement unit (IMU) data and camera image data collected during descent. Therefore, the key point of this technology is to obtain correct corresponding points (i.e. landmarks) between descent images and the reference image map. In this paper, we comprehensively analyze landmark extraction performance that varies depending on flight altitude. As landmark extraction methods, a frequency domain-based method and an image domain-based method are compared. Since the landmark extraction performance decreases as the difference in spatial resolution between a descent image and the reference image map increases, the allowable spatial resolution difference that ensures effective landmark extraction is also analyzed. For the experiments, IMU datasets are generated using a simulated trajectory, and descent image datasets are accordingly generated using a ray tracing technique from the high-resolution image map and digital elevation model. The experimental results of this paper present an appropriate landmark extraction method and reference image map specifications according to flight altitude. Through these results, it would be possible to design an optimized terrain relative navigation for each flight altitude, and as the operational altitude range of terrain relative navigation is expanded, more stable and accurate landing would be possible.
- Abstract document
- Manuscript document
(absent)