1

I have a printed map of a district with several points on it that can be used as geolocation reference points.

I have the shapefile of this map in QGIS. If someone draws a point on the printed map, how can I find the position of the drawn point without scanning the printed map ?

I was thinking of measuring the distance from that point to three other points on the paper, so I can have the zoom used and find the position. Is there a plugin to help with that? Are there other ways to accomplish this?

3
  • This is essentially a math problem. See this answer: math.stackexchange.com/a/100456 you could probably do something in Python to solve this.
    – user52245
    Commented Jan 29, 2017 at 6:22
  • Thanks. If I take the formulas in this answer, can I replace x,y with latitude and longitude or is there a transformation to make using the projection ? Considering that it is the map of a district it is at an important level of zoom and I need a precision at around 50m.
    – syldor
    Commented Jan 29, 2017 at 6:38
  • you should be able to plug in your latitude and longitude. Keep in mind latitude is Y and longitude is X so it's the reverse of how we usually think of things.
    – user52245
    Commented Jan 29, 2017 at 18:56

0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.