Hi all,
I'm doing a simple RF recording with a B200mini synchronized to an accurate GPS 1PPS. I'm attempting to determine which samples(most importantly the first one) fall on a 1PPS pulse. I'm using the File Meta Sink block in GRC to try and extract information from the recording. When I read the data from the header, here is what is shown:
fileName: 'X:\XXXXX.dat'
ifileName: 'X:\XXXXX.idx'
ioType: 'r'
totalPulseCount: 11
sampleCount: 1000000
startTime: [0 0.1120]
timestamp0: '1970-01-01 00:00:00.112'
rx_rate: 1000000
rx_time: [0 0.1120]
timestamp: '1970-01-01 00:00:00.112'
rx_freq: 500000000
sampleType: 'float'
typeFlag: 'double'
vBit: 1
impediance: 50
samples: []
So, this is a 1 MSps recording with a center frequency at 500MHz and about 11 seconds in length, so the extracted information is definitely correct. But a couple of questions from the metadata:
The "startTime" value is 0.1120. I realize that this is the time stamp of the first sample of the segment. However, does that mean that sample 112000 (1MSps*0.1120) is the first sample that falls on a PPS since the B200mini is synced to it?
Second, the "samples" field is empty. I was attempting to populate it with sample numbers that fall on a 1PPS or a header. If the header is synchronized to the 1PPS, this will be fairly easy. If not, is there a way to determine which samples fall on the PPS?
Thanks,
Michael