Hello, I know this discussion is two years old but my comments might benefit some users. This test setup is not valid as the antennas are very close to each other (under 20cm which is a wavelenght at GPS L1). This means that they will couple to each other and affect their radiation patterns. Ideally, you need more space between the antennas (40 cm ++). Also the patch antennas need to be used with a 10 cm (diameter) ground plane directly under them. This is the only way to get the best performance (limit multipath and optimise radiating efficiency). Conclusions from sush a setup can be very misleading because this is not a way a GNSS antenna should be implemented and used.