Set data RGE ALTI menjelaskan model elevasi digital (DEM) Prancis dengan ukuran piksel 1 m. Peta ini dibuat dari survei yang diperoleh dengan lidar di udara atau dengan korelasi gambar udara.
Lidar digunakan untuk area pesisir, hutan besar, dan area yang rawan banjir. Akurasi vertikal DEM di area ini adalah antara
0,2 m dan 0,5 m. Radar digunakan di area pegunungan (Alpen, Pyrenees,
Cevennes, Corsica). Perhatian: di area dengan lereng curam, akurasi vertikal rata-rata adalah sekitar 7 m.
Akurasi kolom ini telah diperiksa berdasarkan berbagai sumber:
jaringan jalan dan hidrografi
BD TOPO, terminal geodetik, dan
titik yang dihitung di lapangan.
Teknik korelasi foto udara digunakan di wilayah lainnya.
Di zona tertentu yang diproses oleh korelasi, pengukuran di lapangan tidak ada di area yang luas karena adanya vegetasi (misalnya, area berhutan). Data altimetri 1987-2001 (BD Alti) digunakan untuk mengisi kesenjangan ini. Akurasi vertikal DEM di area ini
adalah antara 0,5 m dan 0,7 m.
Saat ini, koleksi tersebut mencakup satu gambar IGN/RGE_ALTI/1M/2_0/FXX yang menampilkan Prancis metropolitan.
Set data ini disiapkan dan di-ingest dengan dukungan Guillaume Attard dan Julien Bardonnet (AGEOCE).
Proses persiapannya
dijelaskan di sini.
Set data RGE ALTI menjelaskan model elevasi digital (DEM) Prancis dengan ukuran piksel 1 m. Peta ini dibuat dari survei yang diperoleh dengan lidar di udara atau dengan korelasi gambar udara. Lidar digunakan untuk area pesisir, hutan besar, dan area rawan banjir. Akurasi vertikal DEM di …
[null,null,[],[[["\u003cp\u003eRGE ALTI provides a 1-meter resolution digital elevation model (DEM) of France, derived from airborne lidar and aerial imagery correlation.\u003c/p\u003e\n"],["\u003cp\u003eThe DEM has varying vertical accuracy, ranging from 0.2m to 0.5m in lidar-covered areas (flood-prone, coastal, and forest) and around 7m in mountainous areas surveyed by radar.\u003c/p\u003e\n"],["\u003cp\u003eThe dataset primarily covers metropolitan France and includes bands for elevation, data source, and distance to the nearest data point.\u003c/p\u003e\n"],["\u003cp\u003eThe data is available from 2009 to 2021 and is accessible through Google Earth Engine.\u003c/p\u003e\n"],["\u003cp\u003eRGE ALTI is licensed under etalab-2.0 and provided by IGN.\u003c/p\u003e\n"]]],[],null,["# RGE ALTI: IGN RGE ALTI Digital Elevation 1m\n\nDataset Availability\n: 2009-01-01T00:00:00Z--2021-01-01T00:00:00Z\n\nDataset Provider\n:\n\n\n [IGN](https://geoservices.ign.fr/rgealti)\n\nTags\n:\n[dem](/earth-engine/datasets/tags/dem) [elevation](/earth-engine/datasets/tags/elevation) [elevation-topography](/earth-engine/datasets/tags/elevation-topography) [geophysical](/earth-engine/datasets/tags/geophysical) \n\n#### Description\n\nThe RGE ALTI dataset describes the digital elevation model (DEM) of France\nwith the pixel size of 1m. It was created from surveys obtained by airborne\nlidar or by correlation of aerial images.\n\nLidar was deployed for flood-prone, coastal, and large forest\nareas. The vertical accuracy of the DEM in these areas is between\n0.2m and 0.5m. Radar was used in mountain areas (Alps, Pyrenees,\nCevennes, Corsica). Caution: in areas with steep slopes, the average\nvertical accuracy is the order of 7m.\n\nThe accuracy of these fields has been checked against various sources:\nthe road and hydrographic networks of the\n[BD TOPO](https://geoservices.ign.fr/bdtopo), geodetic terminals and\npoints calculated on the ground.\n\nAerial photo correlation techniques are used in the rest of the territory.\nOn certain zones treated by correlation, ground measurements are absent\nover large extents due to the presence of vegetation\n(wooded areas, for example). 1987-2001 altimetry data (BD Alti) are used\nto fill these gaps. The vertical accuracy of the DEM on these areas\nis between 0.5m and 0.7m.\n\nCurrently the collection includes a single image IGN/RGE_ALTI/1M/2_0/FXX\nshowing metropolitan France.\n\nThis dataset was prepared and ingested with the support of Guillaume Attard\nand Julien Bardonnet ([AGEOCE](https://www.ageoce.com)).\nThe preparation process is\n[described here](https://medium.com/@gui.attard/pre-processing-the-dem-of-france-rge-alti-5m-for-implementation-into-earth-engine-de9a0778e0d9).\n\nSee also:\n[user's guide](https://geoservices.ign.fr/sites/default/files/2021-07/DC_RGEALTI_2-0.pdf).\n\n### Bands\n\n\n**Pixel Size**\n\n1 meter\n\n**Bands**\n\n| Name | Units | Min | Max | Pixel Size | Description |\n|-------|-------|-------|--------|------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `MNT` | m | -40\\* | 4810\\* | meters | Terrain elevation in meters. |\n| `SRC` | | | | meters | The main source of the data used to calculate the altitude of the node. See Appendix B page 26 in the [user guide](https://geoservices.ign.fr/sites/default/files/2021-07/DC_RGEALTI_2-0.pdf). |\n| `DST` | m | 0 | 255 | meters | The distance in meters between the node and the nearest point used to calculate its altitude. |\n\n\\* estimated min or max value\n\n### Terms of Use\n\n**Terms of Use**\n\n[etalab-2.0](https://spdx.org/licenses/etalab-2.0.html)\n\n### Citations\n\nCitations:\n\n- IGN (2021). RGE ALTI 1m \\[Data set\\]. Accessed 2022-07-01 from\n [IGN website](https://geoservices.ign.fr/rgealti#telechargement1m)\n\n### Explore with Earth Engine\n\n| **Important:** Earth Engine is a platform for petabyte-scale scientific analysis and visualization of geospatial datasets, both for public benefit and for business and government users. Earth Engine is free to use for research, education, and nonprofit use. To get started, please [register for Earth Engine access.](https://console.cloud.google.com/earth-engine)\n\n### Code Editor (JavaScript)\n\n```javascript\nvar dataset = ee.Image('IGN/RGE_ALTI/1M/2_0/FXX');\nvar elevation = dataset.select('MNT');\n\nvar elevationVis = {\n min: 0,\n max: 1000,\n palette: ['006600', '002200', 'fff700', 'ab7634', 'c4d0ff', 'ffffff']\n};\n\nMap.addLayer(elevation, elevationVis, 'Elevation');\nMap.setCenter(3, 47, 5);\n```\n[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/IGN/IGN_RGE_ALTI_1M_2_0) \n[RGE ALTI: IGN RGE ALTI Digital Elevation 1m](/earth-engine/datasets/catalog/IGN_RGE_ALTI_1M_2_0) \nThe RGE ALTI dataset describes the digital elevation model (DEM) of France with the pixel size of 1m. It was created from surveys obtained by airborne lidar or by correlation of aerial images. Lidar was deployed for flood-prone, coastal, and large forest areas. The vertical accuracy of the DEM in ... \nIGN/RGE_ALTI/1M/2_0, dem,elevation,elevation-topography,geophysical \n2009-01-01T00:00:00Z/2021-01-01T00:00:00Z \n41.35 -5.2 51.14 9.85 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [](https://doi.org/https://geoservices.ign.fr/rgealti)\n- [](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/IGN_RGE_ALTI_1M_2_0)"]]
