scholarly journals ANALIZA TAČNOSTI ASTER GDEM v3 DIGITALNOG MODELA TERENA

2021 ◽  
Vol 36 (08) ◽  
pp. 1440-1443
Author(s):  
Nemanja Vidić
Keyword(s):  
Aster Gdem

U radu je prikazana detaljna analiza parametara koji definišu kvalitet kreiranog GDEM-a. Nakon opsežne analize dobijenih rezultata, prikazani su i algoritmi kojima se mogu poboljšati vrednosti dobijenih parametara ASTER GDEM-a v3 kojima se definiše tačnost ovog globalnog modela.

Quality Assessment of Globally Available Digital Elevation Model (DEM) for Mountainous Region

2021 ◽  
Vol 5 (1) ◽  
pp. 11-21
Author(s):  
Sangay Gyeltshen ◽  
Krisha Kumar Subedi ◽  
Laylo Zaridinova Kamoliddinovna ◽  
Jigme Tenzin
Keyword(s):  
Digital Elevation Model ◽  
Vertical Displacement ◽  
Satellite System ◽  
Topographic Map ◽  
Alos Palsar ◽  
Aster Gdem ◽  
Digital Elevation ◽  
The Government ◽  
Elevation Model ◽  
The Individual

The study assessed the accuracies of globally available Digital Elevation Models (DEM’s) i.e., SRTM v3, ASTER GDEM v2 and ALOS PALSAR DEM with respect to Topo-DEM derived from topographic map of 5m contour interval. 100 ground control points of the elevation data were collected with the help of kinematic hand held GNSS (Global Navigation Satellite System), randomly distributed over the study area. The widely used RMSE statistic, NCC correlation and sub-pixel-based approach were applied to evaluate the erroneous, correlation, horizontal and vertical displacement in terms of pixels for the individual Digital Elevation Model. Following these evaluations, SRTM DEM was found to be highly accurate in terms of RMSE and displacement compared to other DEMs. This study is intended to provide the researchers, GIS specialists and the government agencies dealing with remote sensing and GIS, a basic clue on accuracy of the DEMs so that the best model can be selected for application on various purposes of the similar region.

scholarly journals AVALIAÇÃO DA ACURÁCIA POSICIONAL PLANIMÉTRICA EM MODELOS DIGITAIS DE SUPERFÍCIE COM O USO DE FEIÇÕES LINEARES

2016 ◽  
Vol 22 (1) ◽  
pp. 157-174 ◽  
Author(s):  
Afonso de Paula dos Santos ◽  
Nilcilene das Graças Medeiros ◽  
Gérson Rodrigues dos Santos ◽  
Dalto Domingos Rodrigues
Keyword(s):  
Aster Gdem ◽  
Alos Prism

Atualmente, tem-se aumentado a preocupação com a avaliação da acurácia posicional em dados espaciais, principalmente em dados com informações altimétricas. Contudo, vários trabalhos avaliam apenas a componente altimétrica, desconsiderando a acurácia posicional planimétrica. Assim, este trabalho tem como objetivo avaliar a acurácia posicional planimétrica dos principais MDSs disponíveis gratuitamente para o Brasil, como os modelos SRTM (banda C e X), Aster GDEM versão 2 e TOPODATA. Para a avaliação da acurácia posicional planimétrica dos MDSs, fez-se a extração de feições características do terreno como linhas de cumeadas e linhas de hidrografia numérica. Em seguida, de posse destas feições lineares, aplicou-se o método do Buffer Duplo para avaliar a acurácia posicional planimétrica de acordo com o padrão definido no Decreto-lei n° 89.817/ET-ADGV. Para a comparação destes modelos, utilizou-se como referência um MDS, na escala de 1:25.000, obtido do sensor ALOS/PRISM. Os resultados da avaliação posicional planimétrica apresentaram Classe C na escala 1:100.000 para os MDS SRTM-X e Aster GDEM; para os MDS TOPODATA e SRTM-C, as classificações obtidas foram Classe B e Classe C na escala de 1:250.000, respectivamente

scholarly journals Mapping of slopes for the operation of agricultural harvesters in Bandeirantes Municipality (PR)

2017 ◽  
Vol 38 (1) ◽  
pp. 97
Author(s):  
Gustavo Rodrigues Gimenes ◽  
Rone Batista Oliveira ◽  
Alessandra Fagioli da Silva ◽  
Luiz Carlos Reis ◽  
Teresinha Esteves da Silveira Reis
Keyword(s):  
Ground Surface ◽  
Digital Terrain Model ◽  
Large Area ◽  
Terrain Model ◽  
Spatial Point ◽  
Aster Gdem ◽  
Digital Terrain ◽  
Contour Lines ◽  
High Resolution Images ◽  
Point Data

The slope of terrain represents a risk factor for mechanized harvesting, leading to impediments or restrictions on agricultural operations, or even to machines toppling over in the field. Recently, the Digital Terrain Model (DTM) has become widely adopted as one of the most viable techniques for obtaining slope and elevation. Therefore, this study aims to assess methods of acquiring DTMs to calculate the slope, and to determine the areas that are suitable and unsuitable for the operation of harvesters in the municipality of Bandeirantes (PR). Four methods were selected to produce DTMs for the construction of slope zoning maps applicable for harvester operations. The image sources included SRTM, ASTER GDEM, digitizing contour lines and kriging of spatial point data. After generating DTMs by the four different methods, the area suitable for the operation of harvesters was obtained based on the limits of operational slopes for harvesters in the literature. The high-resolution images, such as those obtained by scanning the contour lines and ASTER GDEM gave the best representation of the ground surface. Regardless of the method used to obtain the operational slopes, the municipality has a large area that is suitable for mechanized harvesting.

scholarly journals EVALUASI HASIL INTEGRASI BERBAGAI KETELITIAN DATA MODEL ELEVASI DIGITAL

GEOMATIKA ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 39
Author(s):  
Fanny Zafira Mukti ◽  
Harintaka Harintaka ◽  
Djurdjani Djurdjani
Keyword(s):  
Synthetic Aperture Radar ◽  
Data Model ◽  
Thermal Emission ◽  
Light Detection And Ranging ◽  
Synthetic Aperture ◽  
Interferometric Synthetic Aperture Radar ◽  
Light Detection ◽  
Aster Gdem ◽  
Radio Detection ◽  
Global Data

<p>Data DEM yang dapat diakses dan digunakan dengan gratis antara lain adalah <em>Shuttle Radar Topography</em> <em>Mission </em>(SRTM) dan <em>Advanced Spaceborne Thermal Emission and Reflection Radiometer </em>Global DEM (ASTER GDEM). Kedua data tersebut mencakup seluruh wilayah di Indonesia, namun ketelitian dan resolusinya rendah, serta masih mengandung kesalahan tinggi. Selain data DEM global, data DEM dapat diperoleh dari hasil perekaman sensor <em>Radio Detection and Ranging </em>(RADAR), <em>Light Detection and Ranging</em> (LIDAR), maupun hasil <em>stereoplotting</em> foto udara dan citra satelit. Masing-masing data tersebut memiliki karakteristik seperti terdapatnya <em>pit</em> dan <em>spire</em>, diskontinuitas pada daerah sambungan dan ketelitian data yang bervariasi. Keberagaman karakteristik pada masing-masing sumber data tersebut dapat menyebabkan inkonsistensi nilai ketinggian antar sumber data. Pada penelitian ini dilakukan pembuatan DEM dengan data DTM Rupa Bumi Indonesia (RBI) skala 1:50.000 dan data DTM <em>Interferometric Synthetic Aperture Radar </em>(IFSAR) di Pulau Kalimantan yang dapat mengatasi inkonsistensi ketinggian tersebut. Metode yang digunakan adalah integrasi dan fusi DEM pada mozaik data-data ketinggian. Pada daerah yang bertampalan, dilakukan dua skenario mozaik yaitu mozaik tanpa bobot dan mozaik berbobot. Uji akurasi vertikal dilakukan dengan menggunakan standar Peraturan Kepala BIG Nomor 15 Tahun 2014 tentang Pedoman Teknis Ketelitian Peta Dasar. Penelitian ini menghasilkan mozaik data DTM yang <em>seamless</em> dan <em>smooth</em> menggunakan metode mozaik berbobot dengan akurasi vertikal sebesar 2,065 meter. Hasil mozaik tanpa bobot masih memiliki beberapa daerah yang tidak <em>seamless</em> dan <em>smooth </em>dengan akurasi vertikal sebesar 2,257 meter. Berdasarkan Tabel Ketelitian Geometri Peta RBI dalam PerKa BIG Nomer 15 Tahun 2014, kedua hasil mozaik tersebut masuk dalam skala 1:10.000.</p><p>Kata kunci: model elevasi digital, mozaik, integrasi, fusi DEM</p>

scholarly journals Sensibility analysis of VORIS lava-flow simulations: application to Nyamulagira volcano, Democratic Republic of Congo

2015 ◽  
Vol 3 (3) ◽  
pp. 1835-1860
Author(s):  
A. M. Syavulisembo ◽  
H.-B. Havenith ◽  
B. Smets ◽  
N. d'Oreye ◽  
J. Marti
Keyword(s):  
Lava Flow ◽  
Democratic Republic ◽  
Democratic Republic Of Congo ◽  
Lava Flows ◽  
Past Century ◽  
Republic Of Congo ◽  
Political Issues ◽  
Aster Gdem ◽  
Volcano Observatory ◽  
Digital Elevation

Abstract. Assessment and management of volcanic risk are important scientific, economic, and political issues, especially in densely populated areas threatened by volcanoes. The Virunga area in the Democratic Republic of Congo, with over 1 million inhabitants, has to cope permanently with the threat posed by the active Nyamulagira and Nyiragongo volcanoes. During the past century, Nyamulagira erupted at intervals of 1–4 years – mostly in the form of lava flows – at least 30 times. Its summit and flank eruptions lasted for periods of a few days up to more than two years, and produced lava flows sometimes reaching distances of over 20 km from the volcano, thereby affecting very large areas and having a serious impact on the region of Virunga. In order to identify a useful tool for lava flow hazard assessment at the Goma Volcano Observatory (GVO), we tested VORIS 2.0.1 (Felpeto et al., 2007), a freely available software (http://www.gvb-csic.es) based on a probabilistic model that considers topography as the main parameter controlling lava flow propagation. We tested different Digital Elevation Models (DEM) – SRTM1, SRTM3, and ASTER GDEM – to analyze the sensibility of the input parameters of VORIS 2.0.1 in simulation of recent historical lava-flow for which the pre-eruption topography is known. The results obtained show that VORIS 2.0.1 is a quick, easy-to-use tool for simulating lava-flow eruptions and replicates to a high degree of accuracy the eruptions tested. In practice, these results will be used by GVO to calibrate VORIS model for lava flow path forecasting during new eruptions, hence contributing to a better volcanic crisis management.

scholarly journals Análisis de componentes biofísicos del balance de radiación neta, usando teledetección, en la cuenca hidrográfica de Sorocaba con bosque atlántico intervenido, Brasil

2021 ◽  
Author(s):  
Argemiro José Moreno Arteaga ◽  
Manoel Mariano Neto da Silva ◽  
Gabriel Vidal Mota ◽  
Salmi Lizzeth Tapia Aguirre ◽  
Bernardo Barbosa da Silva
Keyword(s):  
Landsat 8 ◽  
Aster Gdem ◽  
América Del Sur

Los ecosistemas forestales, como el bosque atlántico en América del sur, han sido removidos para dar lugar a actividades agropecuarias y asentamiento humanos. Tal situación estaría ocasionando cambios en la absorción de la energía solar en la superficie terrestre, lo que modifica el consumo de radiación neta, que, a su vez, puede influir en la temperatura del aire. Por consiguiente, esta investigación tuvo como objetivo evaluar las alteraciones de la radiación neta en la cuenca hidrográfica de Sorocaba, para analizar cómo el cambio de bosque atlántico por áreas agropecuarias y construcciones antrópicas impacta en la radiación neta y la repercusión que podría estar ocasionando en la regulación del clima local. Para esto fue determinado el balance de radiación en la cuenca y sus componentes biofísicos (NDVI, temperatura superficial, albedo y radiación emitida), por medio del modelo SEBAL, utilizando imágenes OLI/TIRS–Landsat 8 y ASTER(GDEM). Los resultados revelaron que las zonas construidas, seguidas por las agropecuarias, en comparación con la de bosque atlántico, presentan valores de albedo y temperatura superficial superiores, y, consecuentemente, mayores flujos de calor emitido a la atmósfera en forma de radiación infrarroja. Por consiguiente, se generó menores consumo de radiación neta, cuya media para las áreas boscosas, agrícolas, con pastos, suelos desnudos y construidas fue de 712,40Wm-2, 669,40Wm-2, 629,90Wm-2, 616,60Wm-2 y 524,40Wm-2, respectivamente. Así, la deforestación en la cuenca ocasionó que disminuyera la radiación neta y se emita más calor a la atmósfera, lo que favorece el efecto invernadero (principal causante del calentamiento global), en detrimento de poder regular la temperatura del aire.

scholarly journals Aplicación de percepción remota para la detección de cambios en la cobertura boscosa de la reserva ecológica Mache-Chindul

2016 ◽  
pp. 76
Author(s):  
José Muñoz Marcillo ◽  
Elías Cuasquer Fuel ◽  
Oscar Moncayo Carreño ◽  
Diana Delgado Campuzano
Keyword(s):  
Aster Gdem ◽  
Palabras Clave ◽  
Landsat 7 ◽  
Sistemas De Informacion

La Reserva Ecológica Mache-Chindul (REMACH) es una importante área estatal de vegetación natural de la costa norte de Ecuador. Esta investigación tiene como objetivo determinar cambios de la cobertura boscosa entre los años 1998 y 2004 para cuantificar la deforestación, caracterizando paralelamente sus rasgos topográficos de altitud y pendiente. Para este efecto,  aplicando el álgebra de  mapas, análisis de  superficie y geoprocesos de  plataformas como  el procesador de  imágenes y de los Sistemas de Información  Geográfica, se realizó la clasificación supervisada a tres imágenes de satélite Landsat7 ETM de 30 m y el geoanálisis del modelo  de elevación digital global ASTER GDEM con igual resolución espacial. Los resultados determinaron que en la primera parte del período de análisis existió una marcada deforestación, proceso que disminuyó  al final del período, observándose que  en las superficies con menor  pendiente tuvo lugar la reconversión agrícola, en tanto  que  en las áreas de mayor pendiente se dio la reconversión pecuaria. Finalmente se contrastaron los resultados obtenidos, por medio  de  datos de  fuentes globales de  acceso gratuito  en  comparación con  los de fuentes convencionales, comprobando un importante ajuste entre  ambas.  Palabras clave: ASTER GDEM, Landsat 7 ETM, MAXLIKE, REMACH, SIG

scholarly journals ESTIMATION OF DAMAGED AREAS DUE TO THE 2010 CHILE EARTHQUAKE AND TSUNAMI USING SAR IMAGERY OF ALOS/PALSAR

2016 ◽  
Vol III-8 ◽  
pp. 35-42
Author(s):  
Pertiwi Jaya Ni Made ◽  
Fusanori Miura ◽  
A. Besse Rimba
Keyword(s):  
Large Scale ◽  
Aerial Photographs ◽  
Alos Palsar ◽  
Aster Gdem ◽  
Tsunami Damage ◽  
Before And After ◽  
Chile Earthquake ◽  
Multi Temporal ◽  
Sar Imagery ◽  
Inundation Map

A large-scale earthquake and tsunami affect thousands of people and cause serious damages worldwide every year. Quick observation of the disaster damage is extremely important for planning effective rescue operations. In the past, acquiring damage information was limited to only field surveys or using aerial photographs. In the last decade, space-borne images were used in many disaster researches, such as tsunami damage detection. In this study, SAR data of ALOS/PALSAR satellite images were used to estimate tsunami damage in the form of inundation areas in Talcahuano, the area near the epicentre of the 2010 Chile earthquake. The image processing consisted of three stages, i.e. pre-processing, analysis processing, and post-processing. It was conducted using multi-temporal images before and after the disaster. In the analysis processing, inundation areas were extracted through the masking processing. It consisted of water masking using a high-resolution optical image of ALOS/AVNIR-2 and elevation masking which built upon the inundation height using DEM image of ASTER-GDEM. The area result was 8.77 Km&lt;sup&gt;2&lt;/sup&gt;. It showed a good result and corresponded to the inundation map of Talcahuano. Future study in another area is needed in order to strengthen the estimation processing method.

scholarly journals ANALISIS PENGINDERAAN JAUH DAN PEMODELAN 3D FAULT FRACTURE DENSITY (FFD) DALAM PENENTUAN ZONA PERMEABILITAS PERMUKAAN DI WILAYAH PANAS BUMI GUNUNG TAMPOMAS, JAWA BARAT

2021 ◽  
Vol 16 (2) ◽  
pp. 99-118
Author(s):  
Abizar Adi ◽  
Agus Didit Haryanto ◽  
Johanes Hutabarat ◽  
Dewi Gentana
Keyword(s):  
Fracture Density ◽  
Aster Gdem

Wilayah Gunung Tampomas yang terletak di Kecamatan Buahdua, Kecamatan Conggeang, dan Kecamatan Tanjungkerta, Kabupaten Sumedang, Jawa Barat dipilih sebagai daerah penelitian karena diperkirakan memiliki potensi panas bumi dengan hadirnya manifestasi panas bumi berupa mata air panas di sekitarnya. Kemunculan manifestasi berhubungan dengan zona permeabilitas yang dikontrol oleh struktur geologi. Kelurusan punggungan dan lembah diamati dan dianalisis menggunakan citra penginderaan jauh ASTER GDEM dan peta Rupa Bumi Indonesia (RBI), skala 1:25.000. Tujuan penelitian untuk mengetahui hubungan antara permeabilitas dengan kemunculan manifestasi panas bumi di daerah penelitian. Metode penelitian dengan melakukan analisis penginderaan jauh dan Fault Fracture Density (FFD) menggunakan pemodelan 3D micromine software. Hasil analisis penginderaan jauh dengan azimut penyinaran dari 0˚, 45˚, 90˚, 135˚ dan altitude 45˚ memperlihatkan pola utama kelurusan punggungan–lembah yang diinterpretasikan sebagai patahan memiliki arah relatif barat laut-tenggara dan timur laut-barat daya. Indikasi struktur geologi di lapangan diperlihatkan oleh morfologi bentuk punggungan lembah, di beberapa tempat memiliki tebing curam membentuk gawir sesar dan faset segitiga. Hasil analisis FFD di daerah penelitian memiliki tingkat permeabilitas yang bervariasi dengan nilai FFD rendah (0,00–3,00 km-1), sedang (3,00-6,00 km-1) dan tinggi (6,00–9,33 km-1). Manifestasi panas bumi muncul pada zona permeabilitas yang memiliki nilai FFD sedang hingga tinggi yang ditandai oleh warna jingga dan merah. Dari pemodelan 3D micromine software terhadap zona permeabilitas dan ploting mata air panas di permukaan terlihat secara jelas kemunculan mata air panas ke permukaan difasilitasi oleh patahan yang berkembang di daerah penelitian.

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