We need elevation data for topographic analysis, slope and aspect analysis, hydrological analysis, contour generation and other operations. After we have the DEM, how can we easily and quickly export the elevation data to excel format or txt format? The following will provide you with an elevation data crawling tool that can quickly download elevation data.
Click here to download DEM: Elevation data download
When we obtain the DEM data, we can use Rhino/ArcGIS to transform the data and make it visualized. Then we can make an analysis diagram such as the following, and support the digital model to make it more scientifically based and Reference value.
Elevation data crawling download tutorial
Use tool: LSV LSV
is a free 3D digital earth product independently developed by a domestic company. It has very powerful functions. It has hundreds of online map resources, and can also perform 3D previews and various analyses.
After downloading and decompressing, there is no need to install, you can use it directly, or generate a desktop shortcut, which is very convenient, and this software is relatively simple and easy to use.
1. Open LSV, the interface is very clear, there are many functions, basically try to know what it is used for, including line of sight analysis, fill and cut analysis, flooding simulation and so on. First of all, we can search. There are two display modes: Gaode Map and Sky Map. Here I will take the 2020 Green Expo Park in Duyun City, Guizhou Province as an example.
2. In the toolbar, select Download—Extract Elevation—Draw Rectangle/Select the pre-drawn surface (tips: before extracting the elevation, you can adjust to the true north direction in the view, the vertical angle of view), the sampling interval is equivalent to the equal height distance, spacing The smaller the number, the more points. Depending on the size of the site, it can be set to 10~50 meters. Click Extract, then export the data and save it in .csv format.
3. The exported latitude and longitude data correspond to spherical coordinates, and we need to use XYZ when we perform visual analysis later, which are plane coordinates, so coordinate conversion is required.
The first step is to open the Excel table just exported, save the last row of elevation data in a new table, and then arrange the original table in the order of serial number, latitude, and longitude, and then save a .txt format and convert the spaces It is a comma in English.
4. In the second step, open the "Gaussian Coordinates Forward Calculation" (a small tool used to convert the coordinate system), import the saved data, and then we need to find the central meridian degree of the corresponding area according to the longitude value, and then export a copy Open the converted file with Excel, delete the serial number, paste back the elevation data just saved, arrange it in the order of longitude, latitude, and elevation, save it as a .txt format file, and convert the spaces to English The comma and save it is the data we finally get, which can be used for visual analysis.
