Auto takeoff & Alt Hold (with no GPS dependency)

Hi all,

I would like to ask if it is possible to edit the APM v3.2 code to have a new mode which allows me to perform automatic takeoff and then altitude hold. This is to implement on the 3-way aux switch instead of controlling through Mission Planner as I do not have the GPS attached to APM3.2

(The principle work same as the DO_Takeoff in the Planning a Mission in Mission Planner)

The simple answer is yes, probably. But ask the question on drones-discuss Google groups.