hello
maybe i can help out with some info here. what you need as i understand is basicly the correctet cammera position while taking photographs.
you can record gps raw data with a loger on the plane (record antenna deviaton from the camera position)
also during the same time have a other GPS rawdata loger placed on the ground closeby or in the survey area at a known location or make it a known location using long term measurement and post processing ppp. (way i just did in sudan)
then you process the recordings with RTKlib
http://www.rtklib.com/depending on the aircraft speed and other factors such as signal quality obstructions ect. you can use 2 aproches for your data
1. Diferential gps, more robust
2. RTK Phase differential measurements more precise but the GPS signal needs to be recieveded continuisly to interuptions
depending on conditions and base line legth (distance between the two recievers) you can achive an accuracy of 0.5-2m for dgps or a few dm for rtk.
but since the aircraft moves (lets asume 120kts) 62m a second its all relative anyway. if you have your camera and gps clock syncronised its at least not a big problem as for altitude does not change so fast.
you can then process the RTKlib output data (textfile with 3d position) together with your pix in e.g. gpsprune
http://activityworkshop.net/software/gpsprune/this will allow you to write the correctet GPS location into the exif data of your pictures
now you are ready to create your model. but you may have to georeference a bit due to the aircraft moving so fast.
iam pretty sure this is not a clean and accademic correct aproach but this is what i would do.
you will be able to by good hardware GPS reciever and hardware for this kind of work for around 1000euros complete build and testet or build it yourself using kits you will find plenty of information once you get into the RTKlib scene. but be advised its a steep learning curve.
btw i bought my hardware here:
https://www.optimalsystem.de/os.aspx?x=0hope this helps
frank