Solo and two Gps Module... ?

[Hezarfen]

The general approach is to upgrade the gps module but I wonder if it can be used in conjunction with second gps module 3dr Solo?

 

[Pedals2Paddles]

The Solo's stock firmware does not support dual GPS. You need to be on ArduCopter 3.5+ and upgrade to the Pixhawk 2.1 green cube. That said, I'm not sure where you could even put the second GPS on a Solo. The existing GPS bay is the only upward facing location on the Solo. The rest is all covered by the battery.