While this article explains how to go through the process of converting your image to a different coordinate system, we do have the ability to default outputting our products as UTM through your FarmLens user profile under "Application Preferences".
Before starting, this article assumes you have downloaded QGIS and loaded your raster into your project, you can follow the beginning steps of this article to see how that is done.
The point of UTM projection is so that you can get your data in meter units instead of latitude and longitude. Getting your UTM zone:
- Hover your mouse over your image, it will then populate the coordinate box and display the GPS coordinates of your raster:
Moving your mouse around within the raster will change the value, but we just need "somewhere" near your imager to get your UTM zone. - Visit http://www.geoplaner.com/ to enter the GPS coordinates of your data. You will only need to put in the number out to 4 decimal places in most situations, in my case, I'll be entering "34.7719" for the latitude and "136.4903" for the longitude into the yellow box on geoplaner, negative numbers will automatically be handled. Then click "ok":
- You should then notice that the UTM green box will automatically populate with everything you need. In my case I need zone 53 S in the Northern hemisphere, the important part being "N" hemisphere and "53"
Now going back to QGIS, we'll be using this for selecting our projection and updating our data:
- Click on the projection of your data at the bottom
- A window will appear, (1) make sure to check the box "Enable 'on the fly' CRS transformation", (2) type "UTM ZONE XX" where xx is your zone that you identified above, 53 in my case. (3) Find the "WGS 84 / UTM zone XX N/S" that matches what you were identified before. In my case, that's "WGS 84 / UTM zone 53N".
- You'll now notice that the coordinates at the bottom will have changed to significantly larger numbers, this is because they are now in meters
Now you'll need to reproject your data to the proper UTM zone.
- From the menu click "Raster" -> "Projections" -> "Reproject (Warp)"
- In the window it should automatically select your current image, you may need to select it from your drop down. Now you'll want to (1) set the "Output file" to somewhere useful. (2) Select the "Target SRS" equal to what you found from above, "WGS 84 / UTM zone 53N" in my case. Be sure to check the "No data values" box, you should set it to something like "-1000". Finally, click "OK":
- Your image should now be loaded onto the map and rendered.
Comments
0 comments
Please sign in to leave a comment.