scholarly journals New discoveries on astronomical orientation of Inca site in Ollantaytambo, Peru

2015 ◽  
Vol 14 (2) ◽  
pp. 37-46
Author(s):  
Karolína Hanzalová ◽  
Jaroslav Klokočník ◽  
Jan Kostelecký
Keyword(s):  
Digital Elevation Model ◽  
Satellite Images ◽  
Observation Point ◽  
Google Earth ◽  
The Sun ◽  
Winter Solstice ◽  
Machu Picchu ◽  
Digital Elevation ◽  
Elevation Model ◽  
The Temple

<p>This paper deals with astronomical orientation of Incas objects in Ollantaytambo, which is located about 35 km southeast from Machu Picchu, about 40 km northwest from Cusco, and lies in the Urubamba valley. Everybody writing about Ollantaytambo, shoud read Protzen. (1)  He devoted his monograph to description and interpretation of that locality. Book of Salazar and Salazar (2) deals, among others, with the orientation of objects in Ollantaytambo with respect to the cardinal direction. Zawaski and Malville (3) documented astronomical context of major monuments of nine sites in Peru, including Ollantaytambo. We tested astronomical orientation in these places and confirm or disprove hypothesis about purpose of Incas objects. For assessment orientation of objects we used our measurements and also satellite images on Google Earth and digital elevation model from ASTER. The satellite images were used to estimate the astronomical-solar-solstice orientation, together with terrestrial images from Salazar and Salazar (2). The digital elevation model is useful in the mountains, where we need the actual horizon for a calculation of sunset and sunrise on specific days (solstices), which were for Incas people very important. We tested which astronomical phenomenon is connected with objects in Ollantaytambo. First, we focused on Temple of the Sun, also known the Wall of six monoliths.  We tested winter solstice sunrise and the rides of the Pleiades for the epochs 2000, 1500 and 1000 A.D. According with our results the Temple isn´t connected neither with winter solstice sunrise nor with the Pleiades. Then we tested also winter solstice sunset. We tried to use the line from an observation point near ruins of the Temple of Sun, to west-north, in direction to sunset. The astronomical azimuth from this point was about 5° less then we need. From this results we found, that is possible to find another observation point. By Salazar and Salazar (2) we found observation point at the corner (east rectangle) of the pyramid by <em>Pacaritanpu,</em> down by the riverside. There is a line connecting the east rectangular “platform” at the river, going along the Inca road up to vicinity of the Temple of the Sun and then in the direction to the Inca face. Using a digital elevation model we found the astronomical azimuth, which is needed for confirm astronomical orientation of the Temple. So, finally we are able to demonstrate a possibility of the solar-solstice orientation in Ollantaytambo.</p>

scholarly journals New knowledge in determining the astronomical orientation of Incas object in Ollantaytambo, Peru

2014 ◽  
Vol XL-5 ◽  
pp. 273-276 ◽  
Author(s):  
K. Hanzalová ◽  
J. Klokočník ◽  
J. Kostelecký
Keyword(s):  
Digital Elevation Model ◽  
Satellite Images ◽  
Observation Point ◽  
Google Earth ◽  
The Sun ◽  
Winter Solstice ◽  
Machu Picchu ◽  
Digital Elevation ◽  
Elevation Model ◽  
The Temple

This paper deals about astronomical orientation of Incas objects in Ollantaytambo, which is located about 35 km southeast from Machu Picchu, about 40 km northwest from Cusco, and lies in the Urubamba valley. Everybody writing about Ollantaytambo, shoud read Protzen (1993). He devoted his monograph to description and interpretation of that locality. Book of Salazar and Salazar (2005) deals, among others, with the orientation of objects in Ollantaytambo with respect to the cardinal direction. Zawaski and Malville (2007) documented astronomical context of major monuments of nine sites in Peru, including Ollantaytambo. We tested astronomical orientation in these places and confirm or disprove hypothesis about purpose of Incas objects. For assessment orientation of objects we used our measurements and also satellite images on Google Earth and digital elevation model from ASTER. The satellite images used to approximate estimation of astronomical orientation. The digital elevation model is useful in the mountains, where we need the really horizon for a calculation of sunset and sunrise on specific days (solstices), which were for Incas people very important. By Incas is very famous that they worshiped the Sun. According to him they determined when to plant and when to harvest the crop. In this paper we focused on Temple of the Sun, also known the Wall of six monoliths. We tested which astronomical phenomenon is connected with this Temple. First, we tested winter solstice sunrise and the rides of the Pleiades for the epochs 2000, 1500 and 1000 A.D. According with our results the Temple isn't connected neither with winter solstice sunrise nor with the Pleiades. Then we tested also winter solstice sunset. We tried to use the line from an observation point near ruins of the Temple of Sun, to west-north, in direction to sunset. The astronomical azimuth from this point was about 5&deg; less then we need. From this results we found, that is possible to find another observation point. By Salazar and Salazar (2005) we found observation point at the corner (east rectangle) of the pyramid by <i>Pacaritanpu</i>, down by the riverside. There is a line connecting the east rectangular "platform" at the river, going along the Inca road up to vicinity of the Temple of the Sun and then in the direction to the Inca face. Using a digital elevation model we found the astronomical azimuth, which is needed for confirm astronomical orientation of the Temple. So, finally we are able to demonstrate a possibility of the solar-solstice orientation in Ollantaytambo.

scholarly journals Fusion Analysis of Optical Satellite Images and Digital Elevation Model for Quantifying Volume in Debris Flow Disaster

2019 ◽  
Vol 11 (9) ◽  
pp. 1096 ◽  
Author(s):  
Hiroyuki Miura
Keyword(s):  
Debris Flow ◽  
Digital Elevation Model ◽  
Large Scale ◽  
Satellite Images ◽  
Erosion Depth ◽  
Digital Elevation ◽  
Elevation Model ◽  
Fusion Analysis ◽  
Optical Satellite Images ◽  
Debris Flow Disaster

Rapid identification of affected areas and volumes in a large-scale debris flow disaster is important for early-stage recovery and debris management planning. This study introduces a methodology for fusion analysis of optical satellite images and digital elevation model (DEM) for simplified quantification of volumes in a debris flow event. The LiDAR data, the pre- and post-event Sentinel-2 images and the pre-event DEM in Hiroshima, Japan affected by the debris flow disaster on July 2018 are analyzed in this study. Erosion depth by the debris flows is empirically modeled from the pre- and post-event LiDAR-derived DEMs. Erosion areas are detected from the change detection of the satellite images and the DEM-based debris flow propagation analysis by providing predefined sources. The volumes and their pattern are estimated from the detected erosion areas by multiplying the empirical erosion depth. The result of the volume estimations show good agreement with the LiDAR-derived volumes.

scholarly journals Monitoring Deformasi Gunung Merapi Menggunakan Citra Sentinel-1A Dengan Menggunakan Metode DInSAR (Studi Kasus: Gunung Merapi, Jawa Tengah)

2020 ◽  
Vol 4 (1) ◽  
pp. 14-23
Author(s):  
Rian Nurtyawan ◽  
Lady Suci Utami
Keyword(s):  
Digital Elevation Model ◽  
Volcanic Activity ◽  
Satellite Images ◽  
Disaster Mitigation ◽  
Deformation Method ◽  
Differential Interferometry ◽  
Digital Elevation ◽  
Image Pairs ◽  
Elevation Model ◽  
Deformation Map

ABSTRAKIndonesia mempunyai 127 gunung api aktif yang tersebar dari Sabang sampai Merauke. Oleh karena itu, perlu adanya pemantauan aktivitas gunung api yang dapat digunakan untuk acuan mitigasi bencana. Pada penelitian ini menggunakan metode deformasi, metode deformasi merupakan perubahan bentuk, posisi, dan dimensi dari suatu benda. Tujuan dari pemantauan deformasi ini untuk mengetahui perubahan gunung api yang disebabkan oleh aktivitas gunung api. Pemantauan aktivitas gunung api metode deformasi dilakukan dengan menggunakan citra Sentinel-1A yang diolah dengan teknologi Differential Interferometry SAR (DInSAR). Dalam penelitian ini dilakukan pengolahan dengan teknologi DInSAR metode two-pass dari empat buah citra satelit sentinel-1A 10 Januari 2018, 27 Februari 2018, 10 Mei 2018 dan 22 Januari 2019 serta data Digital Elevation Model (DEM) SRTM dengan ketelitian 30 meter .Hasil dari penelitian ini yaitu peta deformasi pra 1 erupsi yang diolah dari pasangan citra 10 Januari 2018 dengan citra 27 Februari 2018 yang menghasilkan deflasi sebesar -0,12 meter, dan peta deformasi pra 2 erupsi yang diolah dari pasangan citra 27 Februari 2018 dan 10 Mei 2018 menghasilkan deflasi sebesar -0,27 meter serta peta pasca erupsi yang diolah dari pasangan citra 10 Mei 3018 dan 22 Januari 2019 menghasilkan deflasi sebesar -0,194 meter.Kata kunci: Deformasi, Gunung Merapi, Sentinel-1A, DInSAR. ABSTRACT Indonesia has 127 active volcanoes spread over from Sabang to Merauke. Therefore, it is necessary to monitor volcanic activity that can be used as a reference for disaster mitigation. In this study, deformation method was used to reflect a change in the shape, position, and dimensions of an object. The purpose of monitoring this deformation is to find out volcanic changes caused by volcanic activity. Monitoring the volcanic activity of the deformation method is carried out using Sentinel-1A images processed with Differential Interferometry SAR (DInSAR) technology. In this research, two-pass method of DInSAR technology was processed using four sentinel-1A satellite images on January 10, 2018, February 27, 2018, May 10, 2018 and January 22, 2019 and SRTM Digital Elevation Model (DEM) data with 30 meters accuracy. This research processed pre-eruption deformation map from the 10 January 2018 imagery pair with the 27 February 2018 image which resulted in a deflation of 0.12 meters. Pre- eruption 2 deformation map was processed from the 27 February 2018 and 10 May 2018 image pairs and resulted in a deflation of 0.27 meters while post-eruption map processed from the 10 May 3018 and 22 January 2019 image pairs resulted in deflation of 0.194 meters.Keywords: Deformation, Merapi Mountain, Sentinel-1A, DinSAR.

scholarly journals Evaluation of the Accuracy of Digital Elevation Model Produced from Different Open Source Data

2019 ◽  
Vol 25 (8) ◽  
pp. 100-112
Author(s):  
Raghad Hadi Hasan
Keyword(s):  
Open Source ◽  
Digital Elevation Model ◽  
Thermal Emission ◽  
Shuttle Radar Topography Mission ◽  
Google Earth ◽  
Reference Points ◽  
Aster Gdem ◽  
Digital Elevation ◽  
Elevation Model ◽  
High Level

This study aims to estimate the accuracy of digital elevation models (DEM) which are created with exploitation of open source Google Earth data and comparing with the widely available DEM datasets, Shuttle Radar Topography Mission (SRTM), version 3, and Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM), version 2. The GPS technique is used in this study to produce digital elevation raster with a high level of accuracy, as reference raster, compared to the DEM datasets. Baghdad University, Al Jadriya campus, is selected as a study area. Besides, 151 reference points were created within the study area to evaluate the results based on the values of RMS.Furthermore, the Geographic Information System (GIS) was utilized to analyze, imagine and interpolate data in this study. The result of the statistical analysis revealed that RMSE of DEM related to the differences between the reference points and Google Earth, SRTM DEM and ASTER GDEM are 6.9, 5.5 and 4.8, respectively. What is more, a finding of this study shows convergence the level of accuracy for all open sources used in this study.  

scholarly journals Geração de Modelo Digital de Elevação utilizando dados do SRTM como subsídio ao planejamento e gestão territorial do município de Lucena(PB)/Generation of Digital Elevation Model using SRTM data as grant to territorial planning and management (...)

2015 ◽  
Vol 26 (45) ◽  
pp. 151
Author(s):  
Erika Rodrigues Dias
Keyword(s):  
Digital Elevation Model ◽  
Three Dimensional ◽  
Shuttle Radar Topography Mission ◽  
Google Earth ◽  
Detailed Knowledge ◽  
Radar Images ◽  
Territorial Planning ◽  
Planning And Management ◽  
Digital Elevation ◽  
Elevation Model

<p>Uma das grandes preocupações da atualidade encontra-se no uso racional das terras, conciliando aspectos sociais, econômicos e ambientais tornando necessário o planejamento territorial através de um conhecimento detalhado da superfície territorial. Dessa forma, é de fundamental importância a representação do terreno. Assim, este trabalho teve por objetivo gerar um modelo digital de elevação – MDE, utilizando imagens de radar SRTM com a finalidade de servir como subsídio à gestão e planejamento territorial. Os materiais utilizados nesse trabalho foram imagens de radar da missão Shuttle Radar Topography Mission – SRTM, imagens obtidas do Google Earth e softwares específicos. Como resultados foram gerados diversos produtos cartográficos que possibilitaram o reconhecimento territorial do município como os mapas de hipsometria e clinografia da área em estudo e a representação tridimensional do relevo visando servir como subsídio à gestão territorial e planejamento do meio físico.</p><p><strong>Palavras-Chave</strong>: Modelo Digital de Elevação, SRTM, Geotecnologias.</p><p><strong>Abstract</strong></p><p>A major concern of today is in the rational use of land, combining social, economic and environmental aspects making it necessary to territorial planning with a detailed knowledge of land area. Thus, it is fundamental to representation of the terrain. Thus, this study aimed to generate a digital elevation model - MDE using SRTM radar images in order to serve as a resource management and territorial planning. The materials used in this work were the mission radar images Shuttle Radar Topography Mission - SRTM, images obtained from Google Earth and specific software. The results were generated several cartographic products enabled the territorial recognition of the city as hypsometry maps and clinografia of the study area and the three-dimensional relief representation to serve as subsidy for territorial planning and management of the physical environment.<strong> </strong></p><p><strong> Keywords</strong>:Digital Elevation Model, SRTM, Geotechnology.</p><p> </p><p> </p>

scholarly journals A 30 m terrace mapping in China using Landsat 8 imagery and digital elevation model based on the Google Earth Engine

2021 ◽  
Vol 13 (5) ◽  
pp. 2437-2456
Author(s):  
Bowen Cao ◽  
Le Yu ◽  
Victoria Naipal ◽  
Philippe Ciais ◽  
Wei Li ◽  
...  
Keyword(s):  
Digital Elevation Model ◽  
Google Earth ◽  
Landsat 8 ◽  
Spectral Features ◽  
Error Matrix ◽  
Cropland Area ◽  
Digital Elevation ◽  
Multi Temporal ◽  
Google Earth Engine ◽  
Elevation Model

Abstract. The construction of terraces is a key soil conservation practice on agricultural land in China providing multiple valuable ecosystem services. Accurate spatial information on terraces is needed for both management and research. In this study, the first 30 m resolution terracing map of the entire territory of China is produced by a supervised pixel-based classification using multisource and multi-temporal data based on the Google Earth Engine (GEE) platform. We extracted time-series spectral features and topographic features from Landsat 8 images and the Shuttle Radar Topography Mission digital elevation model (SRTM DEM) data, classifying cropland area (cultivated land of Globeland30) into terraced and non-terraced types through a random forest classifier. The overall accuracy and kappa coefficient were evaluated by 10 875 test samples and achieved values of 94 % and 0.72, respectively. For terrace class, the producer's accuracy (PA) was 79.945 %, and the user's accuracy (UA) was 71.149 %. The classification performed best in the Loess Plateau and southwestern China, where terraces are most numerous. Some northeastern, eastern-central, and southern areas had relatively high uncertainty. Typical errors in the mapping results are from the sloping cropland (non-terrace cropland with a slope of ≥ 5∘), low-slope terraces, and non-crop vegetation. Terraces are widely distributed in China, and the total terraced area was estimated to be 53.55 Mha (i.e., 26.43 % of China's cropland area) by pixel counting (PC) method and 58.46 ± 2.99 Mha (i.e., 28.85 % ± 1.48 % of China's cropland area) by error-matrix-based model-assisted estimation (EM) method. Elevation and slope were identified as the main features in the terrace/non-terrace classification, and multi-temporal spectral features (such as percentiles of NDVI, TIRS2, and BSI) were also essential. Terraces are more challenging to identify than other land use types because of the intra-class feature heterogeneity, interclass feature similarity, and fragmented patches, which should be the focus of future research. Our terrace mapping algorithm can be used to map large-scale terraces in other regions globally, and our terrace map will serve as a landmark for studies on multiple ecosystem service assessments including erosion control, carbon sequestration, and biodiversity conservation. The China terrace map is available to the public at https://doi.org/10.5281/zenodo.3895585 (Cao et al., 2020).

scholarly journals The Changes of Runoff with DEM Resolution Variations

2020 ◽  
Vol 8 (6) ◽  
pp. 2531-2538
Keyword(s):  
Land Use ◽  
Digital Elevation Model ◽  
Field Measurement ◽  
Surface Runoff ◽  
Satellite Images ◽  
Rational Method ◽  
The Past ◽  
Digital Elevation ◽  
Elevation Model ◽  
Upstream Catchment

Currently there has been a research gap in providing sufficient and reliable data for the estimation of surface runoff from ungauged catchment in Batang Kuranji watershed, City of Padang, West Sumatera, Indonesia. The need for such data arose from the fact that land cover changes occur rapidly in the past 20 years, and flash flood and river degradation have been experienced at an alarming scale. However, due to lack of discharge data from upstream catchment, modelling catchment response to the effect of land use changes is hampered. Field measurement is difficult due to accessibility to river tributaries in the upstream catchment. Therefore, the use of digital satellite images and digital elevation model is studied with various DEM (Digital Elevation Model) resolutions for the first time in this catchment. This catchment is situated from 95 to 1858 m above sea level with an annual rainfall of 3440 mm. This watershed is classified as steep with a watershed that has a slope of more than 40% reaching 37.01% of the entire Kuranji watershed area. This study used 30 m and 8 m DEM. Secondary data were gathered from satellite images such as MODIS (MODerate resolution Imaging Spectroradiometer) Land Use. Precipitation data were gathered from three rain gauging stations in or nearby the catchment. Stream geometry data were obtained from the Provincial Office for River Management. Annual discharge and 100-year discharge are calculated using rainfall data for the past 20 years. Runoff discharge was calculated using rational method and SCS (Soil Conservation Services) method. Overall, computed discharge decreases as DEM resolution decreases with percentage varies between 0.98% to 1.76%. The biggest difference between DEM of 30 m and 8 m was shown by the Rational method. However, the difference between years is inconsistent with methods used with no significant pattern. Using the rational method, the biggest difference was by 18.73 m3/s, making up 1.76%. With SCS-CN, however, the biggest difference was 14 m3/s or 1.32% and the smallest was 0.98%. Validation with field measurement suggests that the 8-m DEM varies only 0.16% with actual discharge. Therefore, in the Kuranji catchment, the SCS method coupled with 8-m DEM was found to be accurate for the estimation of surface runoff

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