GPR Dataset acquired in the GEO1 and GEO3 borehole of the Grimsel Rock Lab during a Salt Tracer Test on the 13th of December 2017.

The dataset contains single-hole and cross-hole multichannel files.

GPR:
4 250MHz Malå Borehole antennas were used in the GEO1 and GEO3 borehole, with the Malå CU2 console.
The antenna separation in GEO1 was fixed at 1.76 m, Receiver (1) on top, Transmitter (2) at the bottom.
The antenna separation in GEO3 was fixed at 5 m, Transmitter (3) on top, Receiver (4) at the bottom.
The antenna conncetions for the respective channels are:
Channel 1: Antenna 2-1
Channel 2: Antenna 2-4
Channel 3: Antenna 3-1
Reflection profiles (Antenna 1-2, Channel 1) were recorded while moving the antenna set from the GEO1 borehole bottom upwards.
A reflection trace was recorded every 10cm. Tomography data was recorded every 20cm along the Channels 2 and 3.
During this time the antenna array in GEO3 was static.

For each profile, the .rad file contains the acquisition parameters (ASCII file) 
and the .rd3 files are the Malå specific files with the raw data. 
The .mch file contains the channel connections (ASCII file).
The number behind the underscore indicates the channel number.

The acquisition times and corresponding filenames are given in the GPR_Notes_20171213.txt file.
The static antenna array positions in GEO3 are given in the GPR_Notes_20171213.txt. 
The positions referes to the bottom of antenna 4 with respect to the borehole bottom.
Due to battery failure and recharging of antennas, the antennas were connected differently for some time steps.
This is indicated in the GPR_Notes_20171213.txt.


Salt Tracer:
Injection in INJ2 interval 4 (borehole depth: 22.89-23.89 m).
The injected tracer amount was 200 L with a conductivity of 60 mS/cm,
consisting of 200 kg water, and 8.04 kg of salt.
The injection lasted for about 100 min, from 10:07.