[Discuss-gnuradio] USRP N210

Hello, all----

I am using USRP N210 with SBX daughterboard 400-4400 MH and GPSDO,

for recording the  GNSS signal (L1 frequency=1575.42 MHz ). I tried to record the signal from GNSS simulator. So I have these problems;

1: I don't know why samples of data go to 1500 and then fluctuates between 1000 and -1000. It then falls and starts to fluctuate between 40 and -40.

anybody has any Idea about what is this overshot? or what are these number?

Here is the In-phase plot :

Thanks.