SPX SPIDAR NIC-500s, Operation Manual

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SPIDAR Software
37
Time Sampling Interval
Also known as Temporal Sampling, this defines how often the GPR wave is sampled at the
GPR receiver, to accurately capture the resulting signal waveform. It is expressed as a time
interval, in picoseconds, between points on a trace (1000ps = 1ns). Antenna frequency affects
the sampling interval; higher frequencies should be sampled at a finer time interval than lower
frequencies to accurately capture the resulting waveform.
The following table displays recommended temporal sampling interval for different frequencies:
Center Frequency
(MHz)
Recommended
Sampling Interval (ps)
12.5 6400
25 3200
50 1600
100 800
200 400
250 400
500 200
1000 100
The minimum value that can be set is 50 ps.
Stacks
In noisy environments, one way to improve the signal to noise ratio is to collect more than one
trace at each position, average them, and then record the average trace; this is known as