All Questions

I work with a Sentinel-2 .jp2 image (red band, 10950 x 10950 pixels). My aim is to reach the same result what SNAP does with a Python script. See the SNAP method and parameters: So this is my ...

I need a Leaflet plugin which extends L.Control.Layers. I have the following requirements: works with Leaflet 1.x handles ungrouped layers alongside grouped ones handles nested layer groups does not ...

I'm trying to implement an open-source NITF reader (using only java, no external libraries such as GDAL or NITRO), and its mostly going OK. However I'm having trouble understanding the RPF extensions, ...

I have used QGIS process 'join attributes by location' in one of the models I have built and I have now been asked to explain in detail exactly how the model is determining the results. I am using it ...

For my own data analysis pipeline, I am running a split screen setup with iPython notebooks on one side, generating variables from source data, pushing them to a CSV file which QGIS then reads/joins ...

I am trying to create a warped VirtualRaster of a Sentinel2 image. Here the Python code I tried: from osgeo import gdal, osr srs = osr.SpatialReference() srs.SetFromUserInput('EPSG:32632') gdal....

I used PostGIS ST_ApproximateMedialAxis to transform polygons representing mountain ranges into a series of lines. Now, I'd like to select only the "longest" line segment for each group, so that I ...

For a little map project of mine, I need to create quadrilaterals around a polygon feature based on the bisected angles of the vertices of that feature. Here is an example: Is it possible to automate ...

I have a layout in QGIS where 3 map views are rotated to 35 deg. The grids automatically rotate to match the maps rotation, however the labels do not. Does anyone know a way to make the coordinate ...

I am looking for an easy way or function to split 2 previously selected line features (generate vertex) at intersecting points (or touching points). See the following picture: I am developing a ...

I am currently trying to extract road networks from OpenStreetMap dumps downloaded on Geofabrik. I am using the following osmosis (version 0.45) command to extract roads: osmosis \ --rbf input.osm....

In trying to generate concave bounding polygons using PostGIS ConcaveHull, I am seeing what I think is strange behavior. When running with a 0.99 tolerance, the resulting polygon shrinks tight as ...

I'm trying to visualize crimes based on if the crime happened during day or night time. I've tried using the point displacement tool but I'm not satisfied with the results because the readability for ...

Can anyone indicate an example of how to do this? Link, tutorial etc... I started a discussion here about how to load a TIFF image like a graph nicely answered by @sehe. But, in this post the image is ...

I want to login to the USGS Earth Explorer website at http://earthexplorer.usgs.gov/ with Python and download imagery from the Landsat Archive collection just by giving it username,password,path/row (...

I have QGIS-Project-Files saved to a network drive and was wondering if it is possible to warn users that a project file is already opened by an other user to prevent concurrent editing of the same ...

I'm working on adding some functionality to a QGIS plugin. It currently uses a QgsSpatialIndex to efficiently compute whether the features of a vector layer intersect (potentially millions) of ...

I have a simple "region" table: id (TEXT), name (TEXT), geom (MULTIPOLYGON). Here's the query I can use to extract a GeoJSON FeatureCollection: SELECT row_to_json(fc) FROM ( SELECT '...

How to digitize in stream mode in Qgis, using a wacom cintiq tablet? freehand it's no use. i need something like MNDR stream digitizing extension for arcview 3.x, which allows continuous tracing, ...

This is related to a previous question How to determine projection parameters when customizing a projection I posted. I am trying to quantitatively evaluate scale distortion associated with choosing ...

I have had success accessing unique database IDs and polygons for various lakes in the US. I'm now looking to get polygons for the watersheds associated with these lakes, but have stumbled a bit. ...

I created a QGIS 3.6 project on Windows Server 2016 x64 with two PostGIS layers: Layer A: Points Layer B: Datatable (No geometries) and configured QGIS Server options on the project like this: Now ...

I am working in QGIS 3.4 with a geopackage file (SQLite database) containing orography information (points, lines and polygons). In QGIS, I have defined by hand a style for every layer in geopackage (...

I have thousands of 3D polygons scattered in space but they mostly overlap with many of their neighbors in big extent. Is there any way how to compute volume they define effectively? I would love ...

I've been cobbling together some Processing scripts for QGIS 2.18 (I'm not a fan of QGIS 3 scripts), and I keep running into one particular problem: my script creates a lot of scratch layers and they ...

I am facing a problem with the new Layout API while implementing a plugin for QGIS 3. Starting point is a layout template in qpt-Format, which contains different elements like (attribute) tables, map, ...

I am using QGIS 2.18.21 and PostgreSQL 9.6. on a Windows 8 machine. I am trying to do processing of a certain database task in the background, and I want the user to be able to continue to work in ...

Does anyone out there know the geometry storage encoding for ESRI's Runtime Geodatabase (.sqlite) format? aka mobile geodatabase. There are 'GDB_ tables', 'st_ tables', 'RTREE indexes' and other ...

does someone knows a possibility to visualize in a bytea column saved photos of a postgresql database in qgis? I would like to store pictures directly into the database, not just the link/ url.

I'm doing a temporal analysis of NDVI and temperature over 17 years, necessitating data from Landsat 5,7, & 8. I'm interested in using level-2 Landsat data available from https://espa.cr.usgs.gov/...

I need to understand the process of creating Mapbox Vector Tiles from OSM data in some detail -- in particular I need to fiddle with cutting out a lot of data (esp. buildings) to keep the final vector ...

Could someone explain how to export from QGIS a 16bit image. I have imported data and coloured it as I want, but need to export it as a 16bit image, as 8bit is giving a terracing effect.I believe I ...

I'm building a map for a certain region with many cities to be displayed. Some of the smaller cities should only be displayed if they don't overlay bigger cities. While the labels of the smaller ...

I have MODIS NDVI TIFF files for a year I want to first clip it with a irregular polygon (not by its extent only) of my study area and save it as a multi band raster in TIFF format The TIFF image are ...

I have a binary raster which I've classified into patches using raster::clump. I now want to efficiently calculate the edge-to-edge, i.e. minimum, pairwise distance between patches. I am currently ...

I'm looking for a C# implementation of the Concave hull (alpha shapes) algorithm. I already found several Java, Python and C++ implementation but no C# version. The other implementation are quite ...

I am trying to solve a large optimization problem where I have a set of nodes on a road network that need to be connected using fibre using the shortest possible amount of fibre. The problem is a ...

I am using ENVI 5.1 on Windows 8. I am trying to open a MOD17A3 (MODIS Net Primary Productivity standard product - L4) .hdf file which I downloaded from the USGS website. I am still a beginner at ENVI,...

I have an open source project I need a similarly open source IP GeoLocation database for. i.e. IP address to country (and ideally city). Ideally with a license that allows redistribution. This is a ...

Rasterizing a vector (shp) I face the following problem: I want my output file (the rasterized vector) to have the same resolution and dimensions as an existing raster. If I understand the interface ...

I have in my possession four sets of shapefiles: 1. Locations (points), around 1000 2. Roads (lines), each road has a speed attribute 3. Terrain (polygons), each zone also has a speed attribute 4. ...

I have polygons drawn with AutoCAD as Mline (Multiline type) which are rendered in QGIS as 8 segments for each feature. An example of one selected feature is shown in the picture below: I want to ...

I'm currently working on some code to automate the creation of a QGIS project from tables in a PostgreSQL DB. For info I'm working in QGIS 3.4. I'm almost there, but I'm stuck on one thing How do I ...

If I define a Vector Layer as an input parameter to a QGIS model, then the parameter name is exposed as a variable in a Field Calculator within the model, however I am unable to use this variable as I ...

I am not able to load accented vowels coming from a Shapefile, to a PostGis geodatabase. This is my information: Operative System: Windows 10. PostgreSql Database: postgresql-10.5-2-windows-x64.exe. ...

My task is to calculate the average ground survey level for each tree in my dataset, using the 3 closest survey points (optionally within a 3m radius of the tree). I want to write this in a Spatial ...

I have a set of vehicles (think railway) that are in a (semi)fixed formation. I know the lead vehicle and I know the GPS coordinates of the lead vehicle at any given time. Sometimes, I can rely on the ...

I'm trying to clip a raster using a polygon but I end up with a result that doesn't seem right and where some raster pixels are outside the polygon used for the clip. See image below where polygon is ...

In a Python application I use gdal.ContourGenerate() to generate contour lines (GDAL version 1.11.4 and 2.2.1) from DTED tiles. DTED tiles overlap at the top and the right with neighboring tiles. ...

I am developing Python QGIS plugin, where I am opening two threads in run function with one thread performing calculation while second thread is printing value looping and when first thread is ...