Question: What is the best way to measure areas of land from aerial mapping photos?

molangmuir10 is asking a question about general: Follow this topic

molangmuir10 asked on July 01, 2019 11:51
149 views | #19940


I want to use aerial mapping photos to create an estimation for the m² of public green space and am wondering the best way to do so!



7 Comments

Hi @molangmuir10 👍

It is quite tough to measure Area of land from Aerial photos I guess as the Area is calculated based on the distance between 2-4 points of a particular location. So, we can use Google Maps for the location, measure the area, then place the image on the exact location with the calculated area.

Check this link for reference. It's quite easy to calculate Area in Google Maps with the default option in the Adress area. ( https://publiclab.org/notes/silentsairam/05-20-2019/increase-in-human-death-space )

https://www.youtube.com/watch?v=XlAjaDDDl2Y -- youtube link.

With photos, normally the shape of any photo could be square, rectangle, etc. So the area might not vary if you measure area with photos.

Is this a question? Click here to post it to the Questions page.

Ah yes of course! I know you can do it in GIS but I don't have the software. This is a good way round it. And maybe this is a feature I will put into my final mapknitter evaluation post! As being able to measure distance and areas directly would be really useful.

Your project looks really interesting, I'm very curious to see how it develops!


Hi all! i was thinking about this in the context of MapKnitter -- i think we have a way to calculate area of a polygon, so for example a single image. But this doesn't help much if a) you have lots of images, esp. overlapping ones, or b) as @silentsairam points out, you want to know the area of sub-zones (like, a lawn) that aren't the same extents as the images themselves.

maybe if we get the Annotations system running again, we could make the area of any polygon drawn appear in the bottom corner or something?

Is this a question? Click here to post it to the Questions page.


Yes this is true. Is there not a way to draw polygons over overlapping images?

Getting the annotations system running, with areas of any polygon drawn in the bottom corner, would be amazing! I'm sure many mapping projects would benefit from being able to estimate polygon areas. Was the annotations system originally used for this?

Is this a question? Click here to post it to the Questions page.


Yes it would be super cool! Until then, try QGIS https://qgis.org/en/site/ -- open source geographic information systems software that you can run on your computer :D


Reply to this comment...


Hi @eymund I think I remember you were working on a project similar to this posted question a couple years back. Do you have any advice on it?

Is this a question? Click here to post it to the Questions page.

Reply to this comment...


Log in to comment