Geometric Accuracy Improvement Method for High-Resolution Optical Satellite Remote Sensing Imagery Combining Multi-Temporal SAR Imagery and GLAS Data

Abstract

With the widespread availability of satellite data, a single region can be described using multi-source and multi-temporal remote sensing data, such as high-resolution (HR) optical imagery, synthetic aperture radar (SAR) imagery, and space-borne laser altimetry data. These have become the main source of data for geopositioning. However, due to the limitation of the direct geometric accuracy of HR optical imagery and the effect of the small intersection angle of HR optical imagery in stereo pair orientation, the geometric accuracy of HR optical imagery cannot meet the requirements for geopositioning without ground control points (GCPs), especially in uninhabited areas, such as forests, plateaus, or deserts. Without satellite attitude error, SAR usually provides higher geometric accuracy than optical satellites. Space-borne laser altimetry technology can collect global laser footprints with high altitude accuracy. Therefore, this paper presents a geometric accuracy improvement method for HR optical satellite remote sensing imagery combining multi-temporal SAR Imagery and GLAS data without GCPs. Based on the imaging mechanism, the differences in the weight matrix determination of the HR optical imagery and SAR imagery were analyzed. The laser altimetry data with high altitude accuracy were selected and applied as height control point in combined geopositioning. To validate the combined geopositioning approach, GaoFen2 (GF2) optical imagery, GaoFen6 (GF6) optical imagery, GaoFen3 (GF3) SAR imagery, and the Geoscience Laser Altimeter System (GLAS) footprint were tested. The experimental results show that the proposed model can be effectively applied to combined geopositioning to improve the geometric accuracy of HR optical imagery. Moreover, we found that the distribution and weight matrix determination of SAR images and the distribution of GLAS footprints are the crucial factors influencing geometric accuracy. Combined geopositioning using multi-source remote sensing data can achieve a plane accuracy of 1.587 m and an altitude accuracy of 1.985 m, which is similar to the geometric accuracy of geopositioning of GF2 with GCPs.

Combined Adjustment Pipeline for Improved Global Geopositioning Accuracy of Optical Satellite Imagery With the Aid of SAR and GLAS

“…This accuracy is close to the nominal accuracy of heterogeneous reference data (GF-3: 3 m; ICESat2: 0.75 m), which demonstrates that our pipeline makes full use of > JSTARS-2022-00438 < multi-source data precision information. Finally, compared with existing pipelines, our pipeline achieves better accuracy and wider applicability; moreover, it benefits from no limit on the accuracy of the auxiliary DEM [13], [15]and does not require stereo SAR images [9], [10], [11]. The proposed pipeline offers the potential for application in global highprecision geo-positioning.…”

“…In terms of applicability, there was only one SAR image in survey area A, and although there were two SAR images in survey areas B and C, stereo image pairs were not formed. As such, stereo SAR and optical combination methods [9], [10], [11] could not be used. Regardless, the method proposed here worked well in all experimental regions, and offers global applicability.…”

“…(2) Combination adjustment of optical satellites and stereo SAR images. Jiao et al [9], [10] and Zhu et al [11] obtained tie points between optical data and SAR through cross-modal matching. The virtual control points were generated by the space intersection (triangulation) of these tie points on the stereo SAR images.…”

Investigation of Perturbations Arising from Temperature Shock with a Symmetrical Arrangement of Flexible Elements of a Small Spacecraft

“…Thus, it is necessary to meet the orientation requirements for remote sensing of the Earth [29][30][31]. These requirements are becoming increasingly high over time due to the increase in remote sensing resolution [32,33].…”

Exploiting High Geopositioning Accuracy of SAR Data to Obtain Accurate Geometric Orientation of Optical Satellite Images

“…However, the classical orientation methods of satellite images are inefficient and have significant limitations in steep terrains. Comprehensive utilization of multi-type sensor data can be a promising solution to achieve a rapid and high-precision geometric orientation of satellite images, promoting fast and accurate global surveying and mapping [21].…”