GCPs and coordinates

Hi guys, 

I am realitively new to RC and especially when it comes to geo location. I get photos from different people and I do not have coordinates and sometimes do not know the camera that they took the photos from. I have been trying to read tutorials on GCPs, but it says that I need to upload the GCP coordinates. I was not given coordinates by people who sent me the photos… how am I able to get coordinates then so photos can be georefereced? I was thinking of going into photoshop and marking areas, but then how can I make accurate coordiante .txt files for them manually (if I have their long/lat coordinates from google and altitude from a dimension they took on site) ?

Please let me know how to do this, I am very new to the coordinate aspect but have to unfortuantely work in this way with a team. I really appreciate the help!

Hello dear user,
if the only thing you can use are google coordinates, it is something at least, but the inaccuracy to the real world using these could be few meters so it is very approximate. You will need to find points on the map which you can see in the photos inside of the project too. Then get the longitude, latitude and altitude of the point on the map and create the text file using the following form:
point 1, lon, lat, alt
point 2, lon, lat, alt
You will need to find and assign each point on 3 photos at least.