Star-Based Methods for Pleiades Hr Commissioning

Fourest, Sébastien; Kubik, Philippe; Lebègue, Laurent; Dechoz, Cécile; Lachérade, Sophie; Blanchet, Gwendoline

doi:10.5194/isprsarchives-xxxix-b1-531-2012

Cited by 27 publications

(11 citation statements)

References 6 publications

(1 reference statement)

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“…The Worldview-3/4 satellite launched in 2014/2016 achieved an image absolute positioning accuracy of 2.7 m (8.7 pixels, 0.31-m resolution) [12][13][14]. To eliminate the need for GCPs, Kubik et al, adopted the extremely agile maneuvers of the Pleiades satellite and developed an auto-calibration imaging mode that enables calibration of the camera-star sensor angle error without the use of GCPs [15][16][17][18]. Jiang similarly developed an autonomous calibration method based on agile-maneuver imaging and verified it by simulation [19,20].…”

Section: Introductionmentioning

confidence: 99%

Star-Based Calibration of the Installation Between the Camera and Star Sensor of the Luojia 1-01 Satellite

et al. 2019

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Ground control points (GCPs) are generally used to calibrate the installation between the camera and star sensor of a satellite in orbit and improve the geometric positioning accuracy of the satellite. However, the use of GCPs for high-frequency calibration is difficult, and it is particularly difficult to acquire accurate GCPs for the image of a nightlight satellite. In this study, we developed a camera-star sensor installation calibration method that eliminates the need for GCPs. In the proposed method, the camera and star sensor lenses are simultaneously pointed at the star, and the camera-star sensor installation is accurately calibrated by processing the star map obtained by the camera and star sensors. Reference data such as road network and Moon position data were used to verify the proposed method and evaluate its positioning accuracy. The results of the application of the method to the positioning of the Luojia 1-01 satellite indicated an accuracy within 800 m, which is comparable with that of the traditional method.

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Section: Introductionmentioning

confidence: 99%

Star-Based Calibration of the Installation Between the Camera and Star Sensor of the Luojia 1-01 Satellite

et al. 2019

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“…The swath width of Pléiades image data is 20 km on ground, that corresponds to 40,000 pixels in across track direction. Interestingly, the Pléiades open star cluster was the best place to steer the eponymous satellite in the calibration phase [31]. For additional information on the Pléiades sensors we refer to References [27,[32][33][34][35].…”

Section: The Pléiades Satellite Systemmentioning

confidence: 99%

Mapping with Pléiades—End-to-End Workflow

2019

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In this work, we introduce an end-to-end workflow for very high-resolution satellite-based mapping, building the basis for important 3D mapping products: (1) digital surface model, (2) digital terrain model, (3) normalized digital surface model and (4) ortho-rectified image mosaic. In particular, we describe all underlying principles for satellite-based 3D mapping and propose methods that extract these products from multi-view stereo satellite imagery. Our workflow is demonstrated for the Pléiades satellite constellation, however, the applied building blocks are more general and thus also applicable for different setups. Besides introducing the overall end-to-end workflow, we need also to tackle single building blocks: optimization of sensor models represented by rational polynomials, epipolar rectification, image matching, spatial point intersection, data fusion, digital terrain model derivation, ortho rectification and ortho mosaicing. For each of these steps, extensions to the state-of-the-art are proposed and discussed in detail. In addition, a novel approach for terrain model generation is introduced. The second aim of the study is a detailed assessment of the resulting output products. Thus, a variety of data sets showing different acquisition scenarios are gathered, allover comprising 24 Pléiades images. First, the accuracies of the 2D and 3D geo-location are analyzed. Second, surface and terrain models are evaluated, including a critical look on the underlying error metrics and discussing the differences of single stereo, tri-stereo and multi-view data sets. Overall, 3D accuracies in the range of 0.2 to 0.3 m in planimetry and 0.2 to 0.4 m in height are achieved w.r.t. ground control points. Retrieved surface models show normalized median absolute deviations around 0.9 m in comparison to reference LiDAR data. Multi-view stereo outperforms single stereo in terms of accuracy and completeness of the resulting surface models.then results in 3D coordinates (i.e., a 3D point cloud) that is resampled into an intermediate DSM. Second, those DSMs are fused and post-processed yielding the final DSM. Within this task, the characteristics of the underlying sensor system is exploited, like availability of image triplets in case of Pléiadesand including high-level processing techniques for the given input. The applicability of high-level processing options, like the semi-global matching (SGM) technique, is investigated, enhanced and resulting achievements are illustrated and validated. 3.In the third task, one DTM and one nDSM are generated solely based on the DSM produced in the previous task. The main steps are ground point filtering, detecting points in the given DSM which are located on bare earth, hole filling to interpolate non-ground information and post-processing mainly for outlier removal. In this way, we can (a) filter man-made structures and vegetation and (b) retrieve vegetation or building heights, finally yielding the DTM and nDSM models. While this is a well-established procedure for airborne light dete...

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“…A star that provides a sufficiently high signal-to-noise ratio (SNR) was selected to clearly distinguish it from the space background (Fourest et al 2012). First, we chose a star with pixel values in the dynamic range of the system without saturation.…”

Section: Star Cluster Selectionmentioning

confidence: 99%

On-orbit MTF estimation for the KOMPSAT-3 satellite using star images

Kang

Chung

Kim

2015

Remote Sensing Letters

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The KOMPSAT-3 (Korean Multi-Purpose Satellite-3) spacecraft was successfully launched on 18 May 2012, with the mission to provide high-resolution imagery for civilian and defence users. Star observation was performed for the purpose of various tests and evaluations such as modulation transfer function (MTF) measurement. This paper describes the method used to estimate KOMPSAT-3 on-orbit MTF performance using star images and presents the results obtained during the commissioning phase. The point spread function (PSF) model was built by estimating the position of the star at the subpixel level and applying a two-dimensional Gaussian curve fitting method. The line spread function (LSF) was derived from the PSF model, and the MTF and the full width at half maximum (FWHM) were estimated as a function of an azimuthal angle and were averaged out for the quantitative estimation. In our study, the MTF in panchromatic band was estimated to be stable at around 16% at the Nyquist frequency, which is a higher value than reported in previous work, and the FWHM was stable at around 1.69. Finally, we concluded that the MTF was maintained stably during star observation period, without any noticeable degradation in the aspect of temporal variation.

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Star-Based Methods for Pleiades Hr Commissioning

Cited by 27 publications

References 6 publications

Star-Based Calibration of the Installation Between the Camera and Star Sensor of the Luojia 1-01 Satellite

Star-Based Calibration of the Installation Between the Camera and Star Sensor of the Luojia 1-01 Satellite

Mapping with Pléiades—End-to-End Workflow

On-orbit MTF estimation for the KOMPSAT-3 satellite using star images

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