Validation of Pleiades Tri-Stereo DSM in Urban Areas

Panagiotakis, Emmanouil; Chrysoulakis, Nektarios; Charalampopoulou, Vasiliki; Poursanidis, Dimitris

doi:10.3390/ijgi7030118

Cited by 31 publications

(28 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As it was observed in the present work, the presence of shadows can affect the quality of the DEM from stereo-satellite imagery ( Figures 5 and 6). A similar problem was identified by [13] when validating the Pleiades tri-stereo digital surface model on an urban area. The fact that Pleiades, stereo and tri-stereo, only obtains images along a fixed trajectory, this limits the view angles of the ground surface (one backward looking, one forward looking, plus a third near-nadir image, in the tri-stereo configuration), making difficult an appropriate DEM estimation from features affected by shadows.…”

Section: The Use Of Pleiades To Survey and Monitor Coastal Areasmentioning

confidence: 62%

“…The first civil satellite constellation that acquired stereoscopic imagery and applied DEM reconstruction over large areas was the French SPOT mission (Satellite Pour l'Observation de la Terre) in 1986 [12]. Since then, several very high spatial resolution satellites with stereo capabilities were launched in response to an increased demand [13]. Among them, the Pleiades constellation (built by the French Space Agency (CNES), commercialized by AIRBUS Defence & Space), consists of two high spatial resolution optical spacecrafts: Pleiades -1A and -1B.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Deriving High Spatial-Resolution Coastal Topography From Sub-meter Satellite Stereo Imagery

et al. 2019

View full text Add to dashboard Cite

High spatial resolution coastal Digital Elevation Models (DEMs) are crucial to assess coastal vulnerability and hazards such as beach erosion, sedimentation, or inundation due to storm surges and sea level rise. This paper explores the possibility to use high spatial-resolution Pleiades (pixel size = 0.7 m) stereoscopic satellite imagery to retrieve a DEM on sandy coastline. A 40-km coastal stretch in the Southwest of France was selected as a pilot-site to compare topographic measurements obtained from Pleiades satellite imagery, Real Time Kinematic GPS (RTK-GPS) and airborne Light Detection and Ranging System (LiDAR). The derived 2-m Pleiades DEM shows an overall good agreement with concurrent methods (RTK-GPS and LiDAR; correlation coefficient of 0.9), with a vertical Root Mean Squared Error (RMS error) that ranges from 0.35 to 0.48 m, after absolute coregistration to the LiDAR dataset. The largest errors (RMS error > 0.5 m) occurred in the steep dune faces, particularly at shadowed areas. This work shows that DEMs derived from sub-meter satellite imagery capture local morphological features (e.g., berm or dune shape) on a sandy beach, over a large spatial domain.Among topographic survey methods of suitable quality, those based on Global Navigation Satellite Systems (GPS), such as Real Time Kinematic GPS (RTK-GPS), have been used extensively to map and monitor coastal morphology [2]. Beach topographic surveys using RTK-GPS method can be performed either by walking and carrying a GPS receiver, or driving a mobile unit (e.g., quad bike). In both cases, the vertical precision is approximately 0.05 to 0.1 m, depending on the terrain relief [2]. This method typically requires an intense human effort, which normally is optimized by reducing the number of measurements to a limited number of cross-shore sections of the beach. Nevertheless, this limited spatial coverage results in an incomplete representation of topographic spatial patterns and evolving features, especially in the case of complex topographies such as steep and unconsolidated slopes. In such cases, interpolation methods are typically required, introducing additional uncertainty into the DEM [3].Remote sensing techniques, such as airborne LiDAR (Light Detection and Ranging) and Unmanned Aerial Vehicle (UAV), emerge in this context as a solution to overcome the limited spatial coverage of the RTK-GPS method [4][5][6][7][8][9]. The use of airborne LiDAR to measure geomorphological changes in coastal areas is relatively new. This instrumentation acquires millions of x, y, z points per hour, with a horizontal spacing of typically 1 to 3 m. This high spatial resolution, together with the capacity to survey over large areas (from 10 1 to 10 5 m), allows overcoming traditional survey limitations found with RTK-GPS [2]. The vertical accuracy of LiDAR ranges from 0.05 m to 0.15 m [5], which is in the same order as RTK-GPS and appropriate for studying beach morphology. Nonetheless, LiDAR-based DEMs are costly [5,6], which limits the frequent (e.g., monthly or-post-...

show abstract

Section: The Use Of Pleiades To Survey and Monitor Coastal Areasmentioning

confidence: 62%

mentioning

confidence: 99%

Deriving High Spatial-Resolution Coastal Topography From Sub-meter Satellite Stereo Imagery

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The two studies achieved RMSEz of 0.75 and 2.4 m, respectively. Panagiotakis et al (2018) achieved an RMSEz of 1.17 m compared to differential GPS measurements in Athens. Bachofer (2017) used the height information derived from a Pléiades triplet to extract building volume information for the Central Business district of Kigali, Rwanda.…”

Section: Introductionmentioning

confidence: 92%

“…Pléiades image triplets have proven their ability in deriving submeter scale elevation and elevation changes (Bagnardi, González, & Hooper, 2016;Zhou, Parsons, Elliott et al, 2015). The tri-stereoscopic configuration allows to retrieve more detailed Digital Surface Models (DSM) in rough terrain or urban areas (Panagiotakis, Chrysoulakis, Charalampopoulou, & Poursanidis, 2018). Poli, Remondino, Angiuli, and Agugiaro (2015) and Perko et al (2014) evaluated the DSM processing of Pléidades imagery in the urban context of Trento and Innsbruck.…”

Section: Introductionmentioning

confidence: 99%

DSM-based identification of changes in highly dynamic urban agglomerations

Warth

Braun

Bödinger

et al. 2019

European Journal of Remote Sensing

View full text Add to dashboard Cite

Rapidly urbanizing areas are challenged by a lack of information on urban growth in many parts of the earth. As the speed of building construction often exceeds traditional surveying methods, remote sensing can serve as a valuable input for the monitoring of urbanization processes. This study investigates changes in DaNang, Vietnam, between 2015 and 2017 identified based on photogrammetric analysis of surface elevations retrieved from Pléiades very high-resolution imagery. In contrast to traditional post-classification change detection approaches, we propose a time-efficient method solely based on digital surface model differencing to identify newly constructed buildings as well as demolitions. It is therefore easy to apply and suitable for the continuation of outdated base data available to local authorities. High importance is addressed to the vertical matching of both surface models to avoid misdetections. After differencing these surface elevations, thresholds based on field measurements are applied to identify areas of change. A total of 10,800 changes were detected between 2015 and 2017, of which 8,531 were to newly constructed buildings. The study proves that changes in rapidly urbanizing agglomerations can be reliably identified by a simple and transparent approach by using elevation changes and expert-based knowledge on floor numbers and building heights. ARTICLE HISTORY

show abstract

“…Note that the presented workflow was already successfully applied by other research groups, for instance, in References [4,110,[134][135][136]. Especially, the DTM generation was applied in References [102,[137][138][139][140][141][142][143]].…”

mentioning

confidence: 99%

Mapping with Pléiades—End-to-End Workflow

2019

View full text Add to dashboard Cite

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...

show abstract

Validation of Pleiades Tri-Stereo DSM in Urban Areas

Cited by 31 publications

References 24 publications

Deriving High Spatial-Resolution Coastal Topography From Sub-meter Satellite Stereo Imagery

Deriving High Spatial-Resolution Coastal Topography From Sub-meter Satellite Stereo Imagery

DSM-based identification of changes in highly dynamic urban agglomerations

Mapping with Pléiades—End-to-End Workflow

Contact Info

Product

Resources

About