Abstract
Abstract. The photogrammetric processing of large area planetary remote sensing images is still a very challenging work. In addition to the lack of ground control data and poor tie points extraction, the insufficient knowledge of the initial geopositioning accuracy of the planetary images also increases the difficulty of processing. This paper presents an automatic evaluation method of the initial geopositioning accuracy for large area planetary remote sensing images. The accuracy evaluation method was conducted through image matching on approximate orthophotos derived using coarse resolution digital elevation model (DEM). To improve the orthophotos generation efficiency of linear pushbroom images, a fast ground-to-image transformation algorithm and multi-threaded parallel computing are adopted. The classical normalized cross correlation (NCC) and pyramid matching schemes are used to perform image matching between overlapping orthophotos. Because the conjugate points on orthophotos contain geographic coordinates, we can derive the statistics information (e.g., maximum errors, mean errors and standard deviation) about the geopositioning accuracy of the planetary images. Although it’s actually an evaluation result of relative accuracy, the quantitative geopositioning accuracy information of stereopairs can be used to (1) specify the search window size and the starting position of conjugate points for tie points extraction; (2) set the weight value of bundle adjustment; and (3) identify images with abnormal geopositioning accuracy. Tens of Mars Express (MEX) High Resolution Stereo Camera (HRSC) images were used to conduct the test. The experimental results demonstrate that the proposed method shows high computational efficiency and automation degree. The automatic evaluation of the initial geopositioning accuracy of the planetary images is helpful to produce large area planetary mapping products.
Highlights
Large area planetary mapping products such as seamless mosaicked Digital Orthophoto Map (DOM) and Digital Elevation Model (DEM) can be used to select landing sites and assess landing safety, which is the basic geographic information data for planetary science (Kirk et al, 2008; Wu et al, 2014; Di et al, 2019)
Take Mars mapping for example, the fusion processing of planetary images returned by Mars Express (MEX) High Resolution Stereo Camera (HRSC), MRO CTX as well as the upcoming China’s first Mars exploration mission (i.e., Tianwen-1) can generate Mars global DOM with a spatial resolution of 10 m/pixel and Mars global DEM with a spatial resolution of better than 50 m/pixel
In order to realize the automatic processing of massive planetary images, it is necessary to clearly know the initial geopositioning accuracy of these images before adjustment
Summary
Large area planetary mapping products such as seamless mosaicked Digital Orthophoto Map (DOM) and Digital Elevation Model (DEM) can be used to select landing sites and assess landing safety, which is the basic geographic information data for planetary science (Kirk et al, 2008; Wu et al, 2014; Di et al, 2019). The recent space exploration missions have returned massive planetary remote sensing images, most of them have not been strictly processed geometrically. The released Mars Express (MEX) High Resolution Stereo Camera (HRSC) Level 4 products were derived by single strip bundle adjustment, such that there are several or dozens of pixels offsets between adjacent strips (Gwinner et al, 2016). The fusion processing of planetary images acquired by different space agencies can derive planetary mapping products with higher resolution and higher accuracy. Take Mars mapping for example, the fusion processing of planetary images returned by MEX HRSC, MRO CTX as well as the upcoming China’s first Mars exploration mission (i.e., Tianwen-1) can generate Mars global DOM with a spatial resolution of 10 m/pixel and Mars global DEM with a spatial resolution of better than 50 m/pixel. It is very meaningful to develop the photogrammetric processing techniques to solve the key problems in geometric processing of large area planetary images (Kirk et al, 2017; Geng et al, 2019)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
