on January 24, 2023
PostGIS change column type varchar => geometry
Geographic Information SystemsHow to change datatype of a column in PostgreSQL? First, specify the name of the table to which the column you want to change belongs in the ALTER TABLE clause. Second, give the name of column whose data type will be changed in the ALTER COLUMN clause. Third, provide the new data type for the
on January 24, 2023
Earth engine reproject: why does reprojecting a pixel at 30m scale gives me pixels with an area of ~550?
Geographic Information SystemsWhat is scale in Google Earth Engine? Understanding how Earth Engine handles scale is crucial to interpreting scientific results obtained from Earth Engine. Here, scale means pixel resolution. Unlike other GIS and image processing platforms, the scale of analysis is determined from the output, rather than the input. How do I change the projection on
on January 24, 2023
Joining polygons with same boundaries
Geographic Information SystemsHow do I merge polygons in the same layer? Note: Click the Edit tool. on the Editor toolbar. Click the features you want to merge. The features must be from the same layer. Click the Editor menu and click Merge. Click the feature that the features will be merged into and will supply the attributes
on January 24, 2023
Determining UTM zone from GeoTIFF in QGIS
Geographic Information SystemsHow do I find UTM zone in Qgis? I find the simple way is to set Google Earth to display UTM coordinates (Tools -> Options) and then fly to a town or other feature that appears on the raster image. The UTM coordinates for the location under the GE pointer appear in the bottom bar,
on January 24, 2023
What geoprocessing tool do I use in order to assign a projected coordinate system to a raster?
Geographic Information SystemsWhat geoprocessing tool would I used to convert the image from one coordinate system to another? Project Raster tool The Project Raster tool is used to transform a raster from one CRS to another. It does change the underlying coordinates. How do I set a projected coordinate system in ArcGIS? Create a coordinate system In
on January 24, 2023
Clipping MBTiles with BoundingBox
Geographic Information SystemsHow do you display your MBTiles? To display MBTiles, upload them directly to Mapbox Studio via the Mapbox Studio tilesets page. Once they have been uploaded, you can either add them to a style or request them directly using Mapbox GL JS or one of the Mapbox mobile SDKs. Note that the mobile SDKs do
on January 24, 2023
Automated creation of perpendicular lines between a point layer and a line layer
Geographic Information SystemsHow do you construct a perpendicular from a point to a line? Quote from video: From this end point swing another arc from over here. And we have two points which is enough for a line. So I'm going to connect. This point of intersection. With the point that we started with. How do you
on January 24, 2023
Relabel vector points in OpenLayers
Geographic Information SystemsHow do I add markers to OpenLayers? How to create a simple map (with a marker) using OpenLayers ? Put a element where you want your map to be. Now you can add a section at the end of the section (after the that loads OpenLayers JavaScript library). You can add a marker at a
on January 24, 2023
Map Info: Thematic Mapping Symbols part printing
Geographic Information SystemsWhat are the four 4 types of thematic maps? Four of the most common types of thematic maps are choropleth maps, dot maps, proportional symbols maps, and flow maps, though there are many other ways to display statistics on maps. What are the 6 visual resources available for thematic mapping? These types include isoline maps,
on January 24, 2023
How to turn off, or have a blank base map, in an AGOL Web App?
Geographic Information SystemsHow do I turn off base map? In the Options dialog box, click Map and Scene. Under the section for setting the default options for basemaps, select None. Click OK. This disables basemap services from being automatically added to new maps. How do I turn off Basemap labels? Answer. No, it is not possible to