Mathematical Modeling and Accuracy Testing of WorldView-2 Level-1B Stereo Pairs without Ground Control Points

Jiang Ye,Xu Lin,Tao Xu

doi:10.3390/rs9070737

Abstract

With very high resolution satellite (VHRS) imagery of 0.5 m, WorldView-2 (WV02) satellite images have been widely used in the field of surveying and mapping. However, for the specific WV02 satellite image geometric orientation model, there is a lack of detailed research and explanation. This paper elaborates the construction process of the WV02 satellite rigorous sensor model (RSM), which considers the velocity aberration, the optical path delay and the atmospheric refraction. We create a new physical inverse model based on a double-iterative method. Through this inverse method, we establish the virtual control grid in the object space to calculate the rational function model (RFM) coefficients. In the RFM coefficient calculation process, we apply the correcting characteristic value method (CCVM) and least squares (LS) method to compare the two experiments’ accuracies. We apply two stereo pairs of WV02 Level 1B products in Qinghai, China to verify the algorithm and test image positioning accuracy. Under the no-control conditions, the monolithic horizontal mean square error (RMSE) of the rational polynomial coefficient (RPC) is 3.8 m. This result is 13.7% higher than the original RPC positioning accuracy provided by commercial vendors. The stereo pair horizontal positioning accuracy of both the physical and RPC models is 5.0 m circular error 90% (CE90). This result is in accordance with the WV02 satellite images nominal positioning accuracy. This paper provides a new method to improve the positioning accuracy of the WV02 satellite image RPC model without GCPs.

Highlights

Rapid technological development of very high resolution satellites (VHRS) has increased commercial high-resolution optical satellite imagery resolution from 1 m to 0.3 m, showing enormous value in the field of surveying and mapping
In the process of constructing the WV02 satellite image using the rigorous sensor model (RSM) model, we considered the influence of velocity aberration, optical path delay and atmospheric refraction in the satellite imaging process, and established a new physical inverse model
The inverse model differs from the existing model by two iterations in each of the object and image spaces

Summary

Introduction

Rapid technological development of very high resolution satellites (VHRS) has increased commercial high-resolution optical satellite imagery resolution from 1 m to 0.3 m, showing enormous value in the field of surveying and mapping. Using a VHRS image, one can quickly obtain fundamental geographic information, such as digital elevation models (DEM), digital orthophoto maps (DOM), and digital line graphics (DLG), which have become some of the primary results of data collection. Before using the image for various applications, we must first build the correct geometric model based on the imaging principle of the satellite sensor. Optical VHRS often use linear charge-coupled device (CCD) push-broom sensors to obtain images. Satellite linear array push-broom imaging differs from aerial images, with special characteristics, such as high flight altitude, a photographically narrow beam, and a small viewing angle [1]. There are two types of satellite geometric positioning models: the rigorous sensor model (RSM), called the physical or camera model, and the rational function model (RFM)

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