Multi-channel GSSI support and distance normalization

[iannesbitt]

Hi again Alain,

I finally got around to writing a GPRPy-specific export function that will create .npy and .json files for each channel as discussed in #3.

Additionally, with regards to the X scale: starting with version 0.0.10, readgssi is capable of distance-normalizing GPR profiles. If the DZT file is accompanied by a DZG (another proprietary GSSI file that contains NMEA GPS records written in ASCII), readgssi can distance-normalize the profile and replace rhf_spm in the header with the newly calculated samples per meter value. If I assume correctly, that should allow GPRPy to properly display the distance scale.

Users can do this in a console:

from readgssi.readgssi import readgssi
readgssi(infile='TEST__002.DZT', frmt='gprpy', normalize=True)

or in a command:

readgssi -N -f gprpy -i TEST__002.DZT

I've attached example files. GPRPy should be able to read them in to look somewhat like the image below (apologies for the ringing)
TEST__002-DZTDZG.tar.xz (file too large to attach, instead hosted from my website)
TEST__002-npyjson.zip

Cheers,
Ian

[alecomunian]

Hello Ian and Alain,

I also needed a way to read with Python dual channel antenna data, and I came across these interesting tools and posts... thank you!

I tried by using GPRPy to split the information contained in the two channels, but unfortunately, as you are well aware of, the support documentation for reading DZT files is somehow incomplete and changing in time.
At the moment, I was able to collect the main steps into a small snippet of code, but I am still unable to collect the TWTT of the two different channels.

Maybe you have a quick suggestion to improve my draft version, that you can find with a DZT example file at the address: https://bitbucket.org/alecomunian/gprchannelsplit/.

Thank you in advance.

Alessandro