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11 votes

How is geolocation by buildings or landmarks in a picture done?

Logan Williams of Bellingcat gave a talk at FOSS4G 2023 called "Investigating war crimes, animal trafficking, and more with open source geospatial data" where he described how they ...
Ian Turton's user avatar
  • 81.8k
8 votes

Removing duplicate point features using QGIS

You can use the QGIS built-in tool named "Delete duplicate geometries" under Processing Toolbox" > Vector general in the Processing Toolbox (Ctrl+Alt+T).
Kadir ┼×ahbaz's user avatar
5 votes

Removing duplicate point features using QGIS

Another solution is the SAGA's "Remove Duplicate Points" tool can be found under SAGA > Features - Points in the Processing Toolbox (Ctrl+Alt+T).
Taras's user avatar
  • 33k
5 votes
Accepted

QGIS - expression join attrributes by location

your expression should be as follows: aggregate( layer:='Aanplant_punt_v01', aggregate:='sum', expression:="amount", filter:= within($geometry, geometry(@parent))) the expression is a field ...
eurojam's user avatar
  • 11.1k
4 votes

How is geolocation by buildings or landmarks in a picture done?

I don't know how the news media do it, but here's how I do it: Develop a rough idea of where the picture was likely taken. Look for features that will show up well in aerial photographs. My first ...
Mark's user avatar
  • 211
4 votes

How to find colinear points given many points?

A solution is given in Find clusters of collinear points from a given set of data points, with the slopes and without computing distance, but there are floating points problems with your data. Another ...
gene's user avatar
  • 55k
3 votes
Accepted

How to find colinear points given many points?

To test the idea I computed 190 lines and count a number of points with distance to line less than 0.1 of maximum distance. Picture shows this distribution: Only 1 line between points 0 and 11 has 10 ...
FelixIP's user avatar
  • 23.1k
1 vote
Accepted

Query geolocation of an address with Overpass API

Overpass API is not a geocoder. Overpass API is designed to query OSM elements by tag. OSM elements don't necessarily have a full address given. Often, some parts of the address (country, postcode, ...
scai's user avatar
  • 6,185
1 vote

GDM2000 or CASSINI to WGS84

I assume that you do not have any software and need to get the conversion done. The method shown below is using QGIS 3.x: You have 2 sets of points: U stands for Utara (North) T stands for Timor (East)...
GforGIS's user avatar
  • 3,126

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