scholarly journals Combined Block Adjustment for Optical Satellite Stereo Imagery Assisted by Spaceborne SAR and Laser Altimetry Data

2021 ◽  
Vol 13 (16) ◽  
pp. 3062
Author(s):  
Guo Zhang ◽  
Boyang Jiang ◽  
Taoyang Wang ◽  
Yuanxin Ye ◽  
Xin Li
Keyword(s):  
Large Scale ◽  
Satellite Image ◽  
Field Measurements ◽  
High Elevation ◽  
Global Scale ◽  
Stereo Image ◽  
Image Process ◽  
Control Points ◽  
Altimetry Data ◽  
Laser Altimetry

To ensure the accuracy of large-scale optical stereo image bundle block adjustment, it is necessary to provide well-distributed ground control points (GCPs) with high accuracy. However, it is difficult to acquire control points through field measurements outside the country. Considering the high planimetric accuracy of spaceborne synthetic aperture radar (SAR) images and the high elevation accuracy of satellite-based laser altimetry data, this paper proposes an adjustment method that combines both as control sources, which can be independent from GCPs. Firstly, the SAR digital orthophoto map (DOM)-based planar control points (PCPs) acquisition is realized by multimodal matching, then the laser altimetry data are filtered to obtain laser altimetry points (LAPs), and finally the optical stereo images’ combined adjustment is conducted. The experimental results of Ziyuan-3 (ZY-3) images prove that this method can achieve an accuracy of 7 m in plane and 3 m in elevation after adjustment without relying on GCPs, which lays the technical foundation for a global-scale satellite image process.

The Efficient Applicability of Highway Alignment Optimization Models

2012 ◽  
Vol 209-211 ◽  
pp. 818-821
Author(s):  
Xiao Yu Sun ◽  
Zhen Qing Wang ◽  
Hong Tao Xing ◽  
Yong Heng Tong
Keyword(s):  
Large Scale ◽  
Engineering Geology ◽  
Low Cost ◽  
Laser Scanner ◽  
Site Investigation ◽  
Pilot Project ◽  
Altimetry Data ◽  
Laser Altimetry ◽  
Highway Alignment Optimization ◽  
Highway Alignment

The total engineering geology approach is applied to a roadway pilot project in the tidal deposits of the Western Netherlands.Its benefit as compared to the conventional geotechnical site investigation is demonstrated.Combining laser scanner altimetry data that is readily available to low cost GEM-2 electromagnetic surveys, allows for the refinement of the local geological model. Small and large scale heterogeneities have been detected in this study. Their existence has been confirmed by a line of closely spaced CPTs. On the basis of laser altimetry and GEM-2 signature, the identified heterogeneities are classified. Only a limited set of heterogeneities representative of the different classes requires a further detailed investigation. Aspects of feasibility, accuracy, and cost-effectiveness have a need for further research.

scholarly journals STUDY OF LARGE-SCALE BLOCK ADJUSTMENT WITH LASER ALTIMETRY DATA GLAS OF ZY3 IMAGES OVER SHANDONG

2020 ◽  
Vol V-2-2020 ◽  
pp. 87-94
Author(s):  
T. Wang ◽  
X. Li
Keyword(s):  
Large Scale ◽  
High Reliability ◽  
Stereo Image ◽  
Waveform Analysis ◽  
Control Points ◽  
Image Correction ◽  
Network Adjustment ◽  
Global Mapping ◽  
The Mean ◽  
Surveying And Mapping

Abstract. In the global mapping work, there will be no control points or uneven distribution of control points. The traditional method of single scene image correction based on ground control points is not suitable for modern surveying and mapping, which has no available control points in a large range. New control data is urgently needed to make up for the influence of traditional control points on surveying and mapping. In this paper, aiming at improving the elevation accuracy of ZY-3 uncontrolled point surveying, a filtering principle based on the analysis based on waveform analysis and the stereo image pair based on tie points is proposed for the screening of GLAS laser elevation points. A new method using high-reliability laser elevation control points as the height constraint and the regional network adjustment of ZY-3 images without control points is studied. Through the experiment in Shandong Province, it is proved that the elevation accuracy of the adjustment can be improved obviously by introducing the selected laser points. The mean error of adjustment elevation is increased from −2.297 to 0.216m and the mean square error of elevation is increased from 3.193m to 2.007m, significantly improving the elevation positioning accuracy of adjustment.

scholarly journals Satellite Stereo Image Processing for 3D Topographic Mapping

2019 ◽  
Vol 1 ◽  
pp. 1-1
Author(s):  
Jaehong Oh ◽  
Changno Lee
Keyword(s):  
High Resolution ◽  
Satellite Data ◽  
Large Scale ◽  
Satellite Image ◽  
Epipolar Geometry ◽  
Stereo Image ◽  
Topographic Mapping ◽  
Positional Accuracy ◽  
Stereo Data ◽  
Rational Polynomial

<p><strong>Abstract.</strong> The large scale topographic map generation is mostly carried out using the aerial images while the high resolution satellite data are gaining popularity because of its large swath width that enables the efficient and economic mapping even over inaccessible areas. To use the satellite data for the 3D topographic mapping, the data should be acquired in the stereo mode and they requires to be aligned for the epipolar geometry. The accurate epipolar image resampling aligns stereo images to enable a stereo display on the computer monitor where human operators can easily identify and extract 3D features, such as points of interest, contours, building layers, and roads. The pushbroom type camera, which is used by most high-resolution satellites, has quite different epipolar geometry than the frame type of aerial or terrestrial cameras. Therefore, the piecewise approach should be used instead of the fundamental matrix approach that is the standard method for the frame type cameras. Regarding the sensor model, most high-resolution satellite data use RPCs (Rational Polynomial Coefficients) of RFM (Rational Function Model) while the frame type camera use the collinearity equation. But RPCs from the satellite image providers have not been accurate enough such that GCPs (Ground Control Points) are often required for improving the RPCs accuracy. The GCPs acquisition is not an easy task over the inaccessible areas and the positional accuracy of the old geospatial data such as orthoimages and traditional maps is relatively low. Fortunately, the positional accuracy of RPCs increases than the past such as up to several meters. The major problem to achieve high accuracy of stereo geometry is to ensure that the consistency between the stereo data is less than one-pixel level. Therefore, in this study, we first utilized the relative orientation method to improve the precision between the stereo data without using any GCP. The tie points are extracted using the robust stereo matching and they are used to generate quasi-GCPs by the space intersection based on the RPCs. The quasi-GCPs are projected back to the stereo data to model and remove the inconsistency in the image space. The improved RPCs were used to accurately align the stereo data for map production.</p>

scholarly journals Surface Level Ozone and its Adverse Effects on Crops and Forests: A Need for an Interdisciplinary Understanding

2001 ◽  
Vol 1 ◽  
pp. 148-149
Author(s):  
Sagar V. Krupa
Keyword(s):  
Adverse Effects ◽  
Large Scale ◽  
Field Measurements ◽  
Ground Level ◽  
Global Scale ◽  
Tree Seedlings ◽  
Loss Assessment ◽  
Surface Level ◽  
Photochemical Oxidant ◽  
The U.S

Surface level ozone (O3) is clearly a global scale problem with regard to its adverse effects on crops, forests and native, terrestrial plant ecosystems. Photochemists and meteorologists are continuing to define the chemistry and physics of the prevalence of O3at the ground level. Similarly, plant scientists in the U.S. and Europe have examined the effects of O3on crops and tree seedlings or saplings through large-scale studies. Examples include the U.S. National Crop Loss Assessment Network (NCLAN), the U.S. EPA’s (Environmental Protection Agency’s) San Bernardino National Forest Photochemical Oxidant Study, European Open-top Chambers Programme (EOTCP), and several ongoing EU (European Union) projects. In addition, there have been studies on mature tree responses through field measurements and by simulation modeling.

scholarly journals High-Precision Digital Surface Model Extraction from Satellite Stereo Images Fused with ICESat-2 Data

2021 ◽  
Vol 14 (1) ◽  
pp. 142
Author(s):  
Jiang Ye ◽  
Yuxuan Qiang ◽  
Rui Zhang ◽  
Xinguo Liu ◽  
Yixin Deng ◽  
...  
Keyword(s):  
Surface Model ◽  
Stereo Pair ◽  
Control Points ◽  
Altimetry Data ◽  
Stereo Images ◽  
Laser Altimetry ◽  
Ice Cloud ◽  
Ground Control Points ◽  
Surface Models ◽  
Abnormal Points

The lack of ground control points (GCPs) affects the elevation accuracy of digital surface models (DSMs) generated by optical satellite stereo images and limits the application of high-resolution DSMs. It is a feasible idea to use ICESat-2 (Ice, Cloud, and land Elevation Satellite-2) laser altimetry data to improve the elevation accuracy of optical stereo images, but it is necessary to accurately match the two types of data. This paper proposes a DSM registration strategy based on terrain similarity (BOTS), which integrates ICESat-2 laser altimetry data without GCPs and improves the DSM elevation accuracy generation from optical satellite stereo pairs. Under different terrain conditions, Worldview-2, SV-1, GF-7, and ZY-3 stereo pairs were used to verify the effectiveness of this method. The experimental results show that the BOTS method proposed in this paper is more robust when there are a large number of abnormal points in the ICESat-2 data or there is a large elevation gap between DSMs. After fusion of ICESat-2 data, the DSM elevation accuracy extracted from the satellite stereo pair is improved by 73~92%, and the root mean square error (RMSE) of Worldview-2 DSM reaches 0.71 m.

scholarly journals A High-Precision Registration Technology Based on Bundle Adjustment in Structured Light Scanning System

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jianying Yuan ◽  
Qiong Wang ◽  
Xiaoliang Jiang ◽  
Bailin Li
Keyword(s):  
High Precision ◽  
Large Scale ◽  
Structured Light ◽  
Bundle Adjustment ◽  
Scanning System ◽  
Control Points ◽  
Registration Method ◽  
Global Control ◽  
3D Data ◽  
Structured Light Scanning

The multiview 3D data registration precision will decrease with the increasing number of registrations when measuring a large scale object using structured light scanning. In this paper, we propose a high-precision registration method based on multiple view geometry theory in order to solve this problem. First, a multiview network is constructed during the scanning process. The bundle adjustment method from digital close range photogrammetry is used to optimize the multiview network to obtain high-precision global control points. After that, the 3D data under each local coordinate of each scan are registered with the global control points. The method overcomes the error accumulation in the traditional registration process and reduces the time consumption of the following 3D data global optimization. The multiview 3D scan registration precision and efficiency are increased. Experiments verify the effectiveness of the proposed algorithm.

scholarly journals Remote Sensing Methods for the Biophysical Characterization of Protected Areas Globally: Challenges and Opportunities

2021 ◽  
Vol 10 (6) ◽  
pp. 384
Author(s):  
Javier Martínez-López ◽  
Bastian Bertzky ◽  
Simon Willcock ◽  
Marine Robuchon ◽  
María Almagro ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Protected Areas ◽  
Large Scale ◽  
Anthropogenic Activities ◽  
Global Scale ◽  
Area Network ◽  
Biophysical Characterization ◽  
Challenges And Opportunities ◽  
Scale Characterization

Protected areas (PAs) are a key strategy to reverse global biodiversity declines, but they are under increasing pressure from anthropogenic activities and concomitant effects. Thus, the heterogeneous landscapes within PAs, containing a number of different habitats and ecosystem types, are in various degrees of disturbance. Characterizing habitats and ecosystems within the global protected area network requires large-scale monitoring over long time scales. This study reviews methods for the biophysical characterization of terrestrial PAs at a global scale by means of remote sensing (RS) and provides further recommendations. To this end, we first discuss the importance of taking into account the structural and functional attributes, as well as integrating a broad spectrum of variables, to account for the different ecosystem and habitat types within PAs, considering examples at local and regional scales. We then discuss potential variables, challenges and limitations of existing global environmental stratifications, as well as the biophysical characterization of PAs, and finally offer some recommendations. Computational and interoperability issues are also discussed, as well as the potential of cloud-based platforms linked to earth observations to support large-scale characterization of PAs. Using RS to characterize PAs globally is a crucial approach to help ensure sustainable development, but it requires further work before such studies are able to inform large-scale conservation actions. This study proposes 14 recommendations in order to improve existing initiatives to biophysically characterize PAs at a global scale.

scholarly journals LARGE SCALE CITY MAPPING USING SATELLITE IMAGERY / KOSMINIŲ NUOTRAUKŲ IŠ GOOGLE EARTH, TAIKOMŲ MIESTAMS KARTOGRAFUOTI STAMBIUOJU MASTELIU, REKTIFIKAVIMAS / РЕКТИФИКАЦИЯ КОСМИЧЕСКИХ СНИМКОВ ИЗ GOOGLE EARTH ДЛЯ КРУПНОМАСШТАБНОГО КАРТОГРАФИРОВАНИЯ ГОРОДОВ

2012 ◽  
Vol 37 (4) ◽  
pp. 168-171 ◽  
Author(s):  
Birutė Ruzgienė ◽  
Qian Yi Xiang ◽  
Silvija Gečytė
Keyword(s):  
Satellite Imagery ◽  
Large Scale ◽  
Modern Technology ◽  
Google Earth ◽  
Aerial Images ◽  
Control Points ◽  
Image Rectification ◽  
Image Deformation ◽  
Map Construction ◽  
Short Period

The rectification of high resolution digital aerial images or satellite imagery employed for large scale city mapping is modern technology that needs well distributed and accurately defined control points. Digital satellite imagery, obtained using widely known software Google Earth, can be applied for accurate city map construction. The method of five control points is suggested for imagery rectification introducing the algorithm offered by Prof. Ruan Wei (tong ji University, Shanghai). Image rectification software created on the basis of the above suggested algorithm can correct image deformation with required accuracy, is reliable and keeps advantages in flexibility. Experimental research on testing the applied technology has been executed using GeoEye imagery with Google Earth builder over the city of Vilnius. Orthophoto maps at the scales of 1:1000 and 1:500 are generated referring to the methodology of five control points. Reference data and rectification results are checked comparing with those received from processing digital aerial images using a digital photogrammetry approach. The image rectification process applying the investigated method takes a short period of time (about 4-5 minutes) and uses only five control points. The accuracy of the created models satisfies requirements for large scale mapping. Santrauka Didelės skiriamosios gebos skaitmeninių nuotraukų ir kosminių nuotraukų rektifikavimas miestams kartografuoti stambiuoju masteliu yra nauja technologija. Tai atliekant būtini tikslūs ir aiškiai matomi kontroliniai taškai. Skaitmeninės kosminės nuotraukos, gautos taikant plačiai žinomą programinį paketą Google Earth, gali būti naudojamos miestams kartografuoti dideliu tikslumu. Siūloma nuotraukas rektifikuoti Penkių kontrolinių taskų metodu pagal prof. Ruan Wei (Tong Ji universitetas, Šanchajus) algoritmą. Moksliniam eksperimentui pasirinkta Vilniaus GeoEye nuotrauka iš Google Earth. 1:1000 ir 1:500 mastelio ortofotografiniai žemėlapiai sudaromi Penkių kontrolinių taškų metodu. Rektifikavimo duomenys lyginami su skaitmeninių nuotraukų apdorojimo rezultatais, gautais skaitmeninės fotogrametrijos metodu. Nuotraukų rektifikavimas Penkių kontrolinių taskų metodu atitinka kartografavimo stambiuoju masteliu reikalavimus, sumažėja laiko sąnaudos. Резюме Ректификация цифровых и космических снимков высокой резолюции для крупномасштабного картографирования является новой технологией, требующей точных и четких контрольных точек. Цифровые космические снимки, полученные с использованием широкоизвестного программного пакета Google Earth, могут применяться для точного картографирования городов. Для ректификации снимков предложен метод пяти контрольных точек с применением алгоритма проф. Ruan Wei (Университет Tong Ji, Шанхай). Для научного эксперимента использован снимок города Вильнюса GeoEye из Google Earth. Ортофотографические карты в масштабе 1:1000 и 1:500 генерируются с применением метода пяти контрольных точек. Полученные результаты и данные ректификации сравниваются с результатами цифровых снимков, полученных с применением метода цифровой фотограмметрии. Ректификация снимков с применением метода пяти контрольных точек уменьшает временные расходы и удовлетворяет требования, предъявляемые к крупномасштабному картографированию.

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