on January 11, 2023
Why is geography faster than geometry for distance calculations?
Geographic Information SystemsWhat is the difference between geometry and geography? Geometry, where it assumes all of your data lives on a Cartesian plane (like a map projection); Geography, where it assumes that your data is made up of points on the earth’s surface, as specified by latitudes and longitudes. How do we calculate distance in geography? Summary.
on January 11, 2023
Substracting raster values from 2 rasters with different cell sizes
Geographic Information SystemsHow do you subtract two raster layers in Arcgis? Procedure In ArcMap, navigate to ArcToolbox > Spatial Analyst Tools > Map Algebra > Raster Calculator. In the Raster Calculator window, double-click one of the rasters to be analysed, click the minus sign (-), and double-click the second raster. Specify the name and location for the
on January 11, 2023
Which projection casts rays from a point on the surface of the globe to a cylinder?
Geographic Information SystemsWhich type of projection is also called cylindrical projection? Mercator projection The familiar Mercator projection (q.v.) is a cylindrical projection. What is cylindrical projection used for? Cylindrical projections are commonly used for world maps, regions bordering the equator, and regions that are predominantly north-south in extent. What is an example of a cylindrical projection? Cylindrical
on January 11, 2023
Putting x y locations into ArcMap?
Geographic Information SystemsSteps for adding x,y data as a layer Click File > Add Data > Add XY Data. Select the table that contains x,y coordinate data. Identify the columns that hold the x- and y-coordinates (and, optionally, the z-coordinate). Specify the coordinate system. How do you add XY coordinates to a shapefile? Right click on your
on January 10, 2023
QGIS raster calculator not keeping each pixel with 1 byte?
Geographic Information SystemsHow do I change the pixel value in Qgis? Editing DEM pixels values in QGIS using Serval Plugin Probe button allows you to check the cell values in the raster. Drawing button activate the ability to modify the values of a raster cell. Clicking on the Set raster cell values to NoData button and then
on January 10, 2023
Choose an attribute dropdown for ArcGIS webbuilder app
Geographic Information SystemsHow do I create a dropdown in ArcGIS online? On your hosted feature layer’s item details page, go to the Data tab>click the Fields button> click on the display name of the field of interest (blue hyperlink)>check out the List of Values (Domain) at the bottom of the screen. If there are choices in a
on January 10, 2023
No image exported from GEE ImageCollection to Cloud Storage
Geographic Information SystemsHow to export images from GEE? to Asset. To export an image to an asset in your Earth Engine assets folder, use Export. image. How do I export a Google cloud VM? Open the Migrate to Virtual Machines page in the Google Cloud console. To export a list of source VMs: Select the Sources tab.Export
on January 10, 2023
Mysterious Lat Long conversion to XY problem using QGIS
Geographic Information SystemsHow do you convert XY coordinates to latitude and longitude in QGIS? Toggle editing (ctrl-E) and open the calculator (ctrl-I). Select “create a new field”, call it “Longitude”, and make the expression $x. Do the same for a second new attribute called “Latitude” and make the expression $y. You should now have latitude and longitude
on January 10, 2023
How can I project a raster DEM and not get serious distortion in the resulting DEM?
Geographic Information SystemsCan you project a raster? A raster dataset is projected into a new spatial reference using a bilinear interpolation approximation method that projects pixels on a coarse mesh grid and uses bilinear interpolation between the pixels. This tool guarantees that the error range is less than half a pixel. How do you give a raster
on January 10, 2023
Benefits of *.las vs *.xyz or *.ascii when working with LiDAR in ArcGIS for Desktop?
Geographic Information SystemsHow do I view LiDAR data in ArcGIS? Procedure Create a LAS dataset. Double-click the LAS dataset. Click the LAS Files tab > Add Files. Open the LAS File Properties and Statistics window by clicking the button below the Statistics column. Click Calculate, and click OK. In the LAS Dataset Properties dialog box, click OK.