scholarly journals THE LATEST DTM USING INSAR FOR DYNAMICS DETECTION OF SEMANGKO FAULT-INDONESIA

2021 ◽  
Vol 47 (3) ◽  
pp. 118-130
Author(s):  
Atriyon Julzarika ◽  
Trias Aditya ◽  
Subaryono Subaryono ◽  
Harintaka Harintaka

The latest Digital Terrain Model (DTM) is seen as an upgradable DTM that is fitted to the latest combination of DTM master and its displacement. The latest DTM can be used to overcome the problem of static DTM weaknesses in displaying the latest topographic changes. DTM masters are obtained from InSAR and Digital Surface Model (DSM) ALOS PALSAR conversions. Meanwhile, the displacement is obtained from Sentinel-1 images, which can be updated every 6–12 days or at least every month. ALOS PALSAR data were the images acquired in 2008 and 2017, while Sentinel-1 data used were images acquired in 2018 and 2020. This study aims to reveal the importance of an upgradable DTM so called latest DTM which is combination of DTM master and its displacement in order to show the latest condition of study area. The case study is the dynamics analyze of the Semangko fault specifically in the Sianok and Sumani segments situated in Indonesia. The vertical accuracy assessment was done to evaluate the DSM to DTM conversion with a tolerance of 1.96σ. The result obtained is the latest DTM. It is derived from the integration of the DTM master with displacement. The latest DTM can be used to detect the dynamics of Semangko fault. The study area has vertical deformation at a value of –50 cm to 30 cm. The Semangko fault area is dominated by –25 to 5 cm deformation. In general, this region has decreased. The decline in this region ranges from 7.5 cm to 10 cm per year. The latest DTM vertical accuracy is 2.158 m (95% confidence level) with a scale of 1: 10,000 to 1: 20,000.

Author(s):  
Lukas Graf ◽  
Mariano Moreno-de las Heras ◽  
Maurici Ruiz ◽  
Josep Fortesa ◽  
Aleix Calsamiglia ◽  
...  

Digital Terrain Models (DTMs) are currently a fundamental source of information in Earth Sciences. However, DTM-based studies can contain remarkable biases if limitations and inaccuracies of these models are disregarded. In this work, four freely available datasets such as SRTM C-SAR DEM, ASTER GDEM V2 and two airborne LiDAR derived DTMs (at 5 and 1 m spatial resolution, respectively) were analysed in a comparative study in three geomorphologically contrasted catchments located in Mediterranean geoecosystems under intensive human land use influence. Vertical accuracy as well as the influence of each dataset characteristics on hydrological and geomorphological modelling applicability were assessed by using classic geometric and morphometric parameters and the more recently proposed index of sediment connectivity. Overall vertical accuracy – expressed as Root Mean Squared Error (RMSE) and Normalized Median Deviation (NMAD) – revealed the highest accuracy in the cases of the 1 m (RMSE = 1.55 m; NMAD = 0.44 m) and 5 m LiDAR DTMs (RMSE = 1.73 m; NMAD = 0.84 m). Vertical accuracy of SRTM was lower (RMSE = 6.98 m; NMAD = 5.27 m) but considerably higher than in the case of ASTER (RMSE = 16.10 m; NMAD = 11.23 m). All datasets were affected by systematic distortions. As a consequence, propagation of these errors caused negative impacts on flow routing, stream network and catchment delineation and, to a lower extent, on the distribution of slope values. These limitations should be carefully considered when applying DTMs for hydrogeomorphological modelling.


2020 ◽  
Author(s):  
Trida Ridho Fariz ◽  
Nur Rokhayati

Salah satu data penginderaan jauh yang penting adalah DEM (Digital Elevation Model). Data DEM memberikan informasi ketinggian suatu permukaan bumi dimana dikelompokkan menjadi 2 yaitu DSM (Digital Surface Model) yang menyajikan informasi ketinggian permukaan tutupan lahan dan DTM (Digital Terrain Model) yang menyajikan informasi ketinggian tanah. Pemetaan banjir rob secara umum menggunakan data DTM. Tetapi untuk mendapatkan data DTM sangatlah sulit. Salah satu data DEM yang tersedia secara gratis adalah data DEM terkoreksi hasil ekstraksi dari ALOS PALSAR yang memiliki resolusi spasial 12,5 meter, tidak terlalu bagus untuk digunakan sebagai data untuk pemetaan genangan banjir rob mengingat itu hanyalah DSM. Sedangkan menggunakan data titik ketinggian yang di interpolasi tidak terlalu merepresentatifkan kondisi ketinggian medan suatu wilayah kecuali jika jumlah titiknya banyak. Penelitian ini menggunakan metode slope based filtering untuk mengkonversi data DEM dari ALOS PALSAR menjadi DTM.Hasil dari metode ini dilakukan uji statistik berupa korelasi dengan data titik ketinggian dan mempunyai nilai korelasi yang sangat tinggi yaitu sebesar 0,80 dan nilai RMSE sebesar 1,402. Selanjutnya dibuat pemodalan spasial genangan banjir rob dari DTM. Hasil pemodelan spasial genanngan banjir rob kemudin diuji akurasi dengan uji statistik korelasi dan penghitungan RMSE dengan data hasil survey lapangan. Hasil pemodelan memiliki korelasi sebesar 0,78 dengan nilai RMSE tinggi genangan banjir rob sebesar 0,763. Yang berarti bahwa rata-rata selisih nilai ketinggian genangan banjir rob dari peta dan dilapangan adalah sebesar 0,763m. Wilayah genangan banjir rob meliputi Desa Jeruksari, Desa Tegaldowo, Desa Mulyorejo dan Desa Karangjompo.


2020 ◽  
Vol 8 (3) ◽  
pp. 207-223
Author(s):  
Rafael Walter Albuquerque ◽  
Marcelo Oliveira Costa ◽  
Manuel Eduardo Ferreira ◽  
Gabriel Cardoso Carrero ◽  
Carlos Henrique Grohmann

Throughout the world, restoration of degraded areas (RDA) is not only a global but also a local challenge. In this context, the Brazilian government committed itself to restore 12 million hectares of forests by 2030. RDA monitoring customarily depends on extensive fieldwork to collect data on all individuals planted. As remotely piloted aircrafts (RPAs) can reduce costs and time of fieldwork activities, studying this technology is therefore timely given. A crucial metric for RDA is the number of trees established in the area. Methods using RPAs on automatic tree counting showed good accuracy using algorithms based on the canopy height model (CHM), which is the difference between a digital surface model (DSM) and a digital terrain model (DTM). However, obtaining a DTM demands an extra computational processing step and may require field control points or manually delimiting objects on the surface. The study presented here proposes and evaluates a semi-automated methodology for counting trees directly on DSM in RDAs in the Amazon using RPA coupled with a red–green–blue standard photographic sensor. The DSM method obtained good overall accuracy and F-score indexes, superior to the CHM method for all study areas even when overall accuracy was low for both methods.


2011 ◽  
Vol 3 (5) ◽  
pp. 845-858 ◽  
Author(s):  
Kande R.M.U. Bandara ◽  
Lal Samarakoon ◽  
Rajendra P. Shrestha ◽  
Yoshikazu Kamiya

2019 ◽  
Vol 7 (1) ◽  
pp. 1-20
Author(s):  
Fotis Giagkas ◽  
Petros Patias ◽  
Charalampos Georgiadis

The purpose of this study is the photogrammetric survey of a forested area using unmanned aerial vehicles (UAV), and the estimation of the digital terrain model (DTM) of the area, based on the photogrammetrically produced digital surface model (DSM). Furthermore, through the classification of the height difference between a DSM and a DTM, a vegetation height model is estimated, and a vegetation type map is produced. Finally, the generated DTM was used in a hydrological analysis study to determine its suitability compared to the usage of the DSM. The selected study area was the forest of Seih-Sou (Thessaloniki). The DTM extraction methodology applies classification and filtering of point clouds, and aims to produce a surface model including only terrain points (DTM). The method yielded a DTM that functioned satisfactorily as a basis for the hydrological analysis. Also, by classifying the DSM–DTM difference, a vegetation height model was generated. For the photogrammetric survey, 495 aerial images were used, taken by a UAV from a height of ∼200 m. A total of 44 ground control points were measured with an accuracy of 5 cm. The accuracy of the aerial triangulation was approximately 13 cm. The produced dense point cloud, counted 146 593 725 points.


2011 ◽  
Vol 90-93 ◽  
pp. 2818-2821
Author(s):  
Dong Ling Ma ◽  
Jian Cui ◽  
Ning Ding

INPHO is foreign professional digital photogrammetry software, including aerial triangulation encryption, digital terrain model matching, the digital orthophoto rectification and image mosaic series modules. This paper, taking DMC image as a case study, according to production practice, states the method of making Digital Orthophoto Map (DOM) using all relevant modules of INPHO, and further points out several notes in the process of making DOM. Practice shows that making DOM using INPHO series software and paying attention to the mentioned precautions can speed up production rate, improve production efficiency, while its mode of operation is also greatly simplified compared with the normal mode of operation. It is a good way of making DOM.


2016 ◽  
Vol 19 (2) ◽  
pp. 28-31
Author(s):  
Jozef Sedláček ◽  
Ondřej Šesták ◽  
Miroslava Sliacka

Abstract The paper investigates suitability of digital surface model for visibility analysis in GIS. In experiment there were analysed viewsheds from 14 observer points calculated on digital surface model, digital terrain model and its comparison to field survey. Data sources for the investigated models were LiDAR digital terrain model and LiDAR digital surface model with vegetation distributed by the Czech Administration for Land Surveying and Cadastre. The overlay method was used for comparing accuracy of models and the reference model was LiDAR digital surface model. Average equalities in comparison with LiDAR digital terrain model, ZABAGED model and field survey were 15.5 %, 17.3% and 20.9%, respectively.


Author(s):  
F. Fassi ◽  
L. Perfetti

<p><strong>Abstract.</strong> The paper presents the case study of the complete 3D survey of the area of the Fort of Pietole in Borgo Virgilio using the Leica Pegasus Backpack wearable Mobile Mapping System (MMS). Surveying the site is challenging because of its complex topology on the one hand (with notably narrow passages) and because of the presence of vegetation on the other. The framework within which this research takes place is the Fort of Pietole survey project that aims at the extraction of the Digital Terrain Model (DTM) of the area and the georeferencing of the fort defensive structures. The requirement of the project is the 3D reconstruction of the whole area at an accuracy that stands between a big scale environmental survey and a small-scale architectonic survey (1&amp;thinsp;:&amp;thinsp;500).</p> <p>The project is the opportunity to discuss the state of the art of wearable MMS, and to test the versatility and accuracy outcomes of the Pegasus Backpack under varying and challenging condition (indoor-outdoor, even-uneven pavement, satellite covered-denied areas) with the ambitious goal to use only the backpack MMS to record all the data from the DTM to the indoor narrow structures.</p>


2018 ◽  
Author(s):  
Jens Ingensand ◽  
Jean Christophe Foltête ◽  
Stéphane Cretegny ◽  
Nicolas Blanc ◽  
Sarah Composto

This paper describes a method that uses georeferenced landscape pictures extracted from open picture collections for the determination of the population's interest in spatial features. The automated method takes into account the coordinates of the camera position as well as the azimuth angle, the focal length and the crop factor in order to calculate a field of view using a digital terrain model (DTM). This field of view can thereafter be used for the determination of interest in spatial features. In a case study involving more than 3'000 georeferenced pictures we investigate the potential of the method.


2021 ◽  
Vol 50 (1) ◽  
pp. 75-89
Author(s):  
Mark Abolins ◽  
Albert Ogden

A novel method to map and quantitatively describe very gentle folds (limb dip <5°) at cratonic cave sites was evaluated at Snail Shell and Nanna caves, central Tennessee, USA. Elevations from the global SRTM digital terrain model (DTM) were assigned to points on late Ordovician geologic contacts, and the elevations of the points were used to interpolate 28 m cell size natural neighbor digital elevation models (DEM’s) of the contacts. The global Forest Canopy Height Dataset was subtracted from the global 28 m cell size AW3D30 digital surface model (DSM) to create a DTM, and that DTM was applied in the same way. Comparison of mean and modal strikes of the interpolated surfaces with mean and modal cave passage trend shows that many passages are sub-parallel to the trend of an anticline. WithiSn 500 m of the caves, the SRTM- and AW3D30-based interpolated surfaces have mean strikes within 8° of the mean strike of an interpolated reference surface created with a high resolution (~0.76 m cell size and 10 cm RMSE) Tennessee, USA LiDAR DTM. This evaluation shows that the SRTM- and AW3D30-based method has the potential to reveal a relationship between the trend of a fold, on one hand, and cave passages, on the other, at sites where a geologic contact varies in elevation by >35 m within an area of <12.4 km2 and the mean dip of bedding is >0.9°.


Sign in / Sign up

Export Citation Format

Share Document