Jeff, Jake and I went to Tsaghkahovit today around 2 to survey with the gpr in the units set up yesterday (1, 2 and 3) and to make up for the lost time working with the calibration. We got to the site and set up the first unit, which I called Unit 1 and which is the furthest (east) from Lori's trench. See notebook for sketch/rough drawing. The long axis of these three 20 by 20 m units (ie. 60 m) is the X axis, and the short 20 m side is the Y axis. We had ten lines that we set up for .25 m spacing (.5 m apart) and I started with the GSSI for the first unit, in Grid 001, with the following parameters:
RADAR- 400 mHz, T rate 100 kHz, Distance Mode, No GPS
3D GRID- X start 0, X end 20; Y start 0, Y end 20; X line spacing 0, Y line spacing .25
POSITION- Manual, Offset -0.09, Surface % 0.00
GAIN- Manual, Pts 5, GP1 -20, GP2 34, GP3 38, GP4 48, GP5 48
SCAN- smp 512, Format 16 bit, Range 80 nS, DIEL 9.00, TEST_DIEL off, Rate 120, SCN/Unit 100
FILTER- LP IIR 1455, HP IIR 50, LP FIR 0, HP FIR 0, Stacking 0, BGR_RML 0, MIGR off
Calibration for Grid 001 was 1315.10.
These parameters continued for the rest of the units, except for the calibration which changed. At line 59 (14.5 m) of the first unit I had to recalibrate because of the rocks and I set it to the same value, but I was now in Grid 002, starting at 14.5 m and continuing to the end. There were a number of very large to medium sized rocks in these three units which from the surface look like both walls as well as natural outcrops, I sketched them in the notebook. It caused the antenna to jump several times when Jeff and I were walking and we got some beeps indicating the speed was too high.
After I finished the first unit Jeff and I switched and he finished unit 2 with Grid 003 and Grid 004 (switching at about the 5 m mark because the battery died) with a calibration value of 1293.
After conferring with Jake who at this point started to help us pull lines, we decided to try for the third unit with 50% battery remaining. I did the first ten meters but had a hard time calibrating in Grid 005 so switched to Grid 006 and walked in a relatively flat, rock-free area and got a calibration value of 1293. Jeff took over at the 10 m mark (still in Grid 006) and walked until 16.75 m when the second battery died, roughly 3 meters (13 lines) from the finish. We decided not to try and come back and finish those lines since they were right next to Lori's trench. We finished around 9 pm.
Unit 1: Grid 001, 002
Unit 2: Grid 003, 004
Unit 3: Grid 006 *up to 16.75 m