Abstract
This paper validates the potentials of Worldview-3 satellite images in large scale topographic mapping, by choosing Worldview-3 along-track stereo-images of Yi Mountain area in Shandong province China for DEM extraction and accuracy evaluation. Firstly, eighteen accurate and evenly-distributed GPS points are collected in field and used as GCPs/check points, the image points of which are accurately measured, and also tie points are extracted from image matching; then, the RFM-based block adjustment to compensate the systematic error in image orientation is carried out and the geo-positioning accuracy is calculated and analysed; next, for the two stereo-pairs of the block, DSMs are separately constructed and mosaicked as an entirety, and also the corresponding DEM is subsequently generated; finally, compared with the selected check points from high-precision airborne LiDAR point cloud covering the same test area, the accuracy of the generated DEM with 2-meter grid spacing is evaluated by the maximum (max.), minimum (min.), mean and standard deviation (std.) values of elevation biases. It is demonstrated that, for Worldview-3 stereo-images used in our research, the planimetric accuracy without GCPs is about 2.16 m (mean error) and 0.55 (std. error), which is superior to the nominal value, while the vertical accuracy is about -1.61 m (mean error) and 0.49 m (std. error); with a small amount of GCPs located in the center and four corners of the test area, the systematic error can be well compensated. The std. value of elevation biases between the generated DEM and the 7256 LiDAR check points are about 0.62 m. If considering the potential uncertainties in the image point measurement, stereo matching and also elevation editing, the accuracy of generating DEM from Worldview-3 stereo-images should be more desirable. Judging from the results, Worldview-3 has the potential for 1:5000 or even larger scale mapping application.
Highlights
In recent years, the commercial optical satellites with sub-meter high resolution have been developing fast
This study aims at exploring the characteristics of the WV-3 in acquiring wide-coverage stereo-images, and validating the potentials of WV-3 in high accuracy elevation extraction for large scale topographic mapping, by using WV-3 along-track stereo-images of a mountainous area in Shandong province China, where the airborne LiDAR point cloud is used to verify the quality of the DEM generated
Quantitative accuracy evaluation of generated DEM is performed based on an overall bias calculation method: get the planimetric coordinates and elevation value of check points from the LiDAR point cloud data; and according to the planimetric coordinates, find the elevation values of corresponding points on generated DEM; and make subtraction calculation to get elevation biases of all check points one by one, after which the max., min., mean and std. values of biases can be derived
Summary
The commercial optical satellites with sub-meter high resolution have been developing fast. The performance indexes such as geo-referencing accuracy, mapping capability etc. Operating at an altitude of 617 km with an inclination of 97.2°for a maximum orbital period of 97 minutes, WV-3 provides 0.31 m panchromatic resolution, 1.24 m multispectral resolution, 3.7 m short-wave infrared resolution, and 30 m CAVIS resolution. It is the industry’s first multipayload, super-spectral, high-resolution commercial satellite, and provides significant improvements in image resolution and geo-positioning accuracy. This capacity opens the way to various acquisition scenarios matching different applications, e.g. automatically extracting 3-D information over significant land areas from the multiple-view (at least triple) stereo-images, collecting the multiple-strip image of a wide coverage in a single pass, and acquiring stereo-images for 3-D extraction purposes of a wide coverage by stitched stereo imaging in a single pass
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: ISPRS - 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.
