GPS positioning for quadcopter

[miki]

I am an engineering undergraduate student. I am currently working on a project to implement a sensing package on a quadcopter for the deployment in the canopy of tropical rain forests. This package needs to measure temperature, humidity, pressure and light intensity. All these have been taken care of, but it also needs to precisely obtain the position of the quadcopter and I am not sure how to achieve this. As it will operate in a rain forest, a standard GPS will probably not be accurate enough in part due to the bad signal (forest means a lot of trees and vegetation around). I am building everything on an Arduino Mega 2560 board(see datasheet http://www.kynix.com/uploadfiles/pdf8827/ATMEGA2560-16AU.pdf). I was thinking on using D-GPS but I am not sure how to implement it.

Does someone know how I could obtain a precise (submeter precise) position of the quadcopter?

 

[Wildwelder]

I dont think operating a drone through thick rainforest via gps will happen anytime soon. Above the canopy yes but through it.... nope. Were not there yet, if ever. We dont have perfect gps stability yet. Were about +- 1.5 meters. And thats with a perfect 6-10 satellite lock. In a rainforest you have a broken expensive drone. Thats my opinion. Anyone else?

 

[RENOV8R]

I doubt it will ever happen, the government (specifically the military) frowns upon civilians possessing devices that can fly to a location with pinpoint accuracy.

 

[Pawlik]

I doubt it will ever happen, the government (specifically the military) frowns upon civilians possessing devices that can fly to a location with pinpoint accuracy.

A meter or two is plenty pinpoint enough to be a national security concern, but his problem is the trees. I would think some sort of ground based GPS "proxy" transmitters would be necessary.