How to measure GPS antenna sensitivity?

[Yusuke]

I would like to compare GPS antenna sensitivity between DK board and a custom board. What AT command achieves it? Thanks.

[Heidi]

So the CN0 value is an indication of signal strength, but it is quite unreliable when comparing receive sensitivity in live conditions.

The measurements should be taken from exactly the same place at exactly the same time (preferably using the same antenna), otherwise the comparison is contaminated by antenna performance, multipath distortions etc.