On Sunday we headed over to our usual site to do another resistivity survey. It was windy and overcast but perfect weather for survey work.
We chose to start by surveying grid square D9, adjacent to two squares previously surveyed. The results are shown below (click on the image for a larger view):
The plot shows eight different visualisations of the data results for D9. Low resistance is shown by blue in the colour plots, and by darker shades in the grey shade plots. One feature of interest is a crescent shaped arc of low resistance, to the left centre of the plots. This is best seen in the top six plots. The plots also suggest quite a bit of disturbance, particularly in the southern half of the square. Note that the small block of readings with the same value in the extreme bottom right corner of the square represent dummy readings, as the square is impinged by a fence.
We then moved on to square D7, which is towards the northern edge of the promontory. The results are shown below (click on the image for a larger view):
This plot shows an interesting area of high resistance (red and orange area), although as this area represents the crown of the hill, there is always the possibility that some variation is caused by natural change in the ground conditions.
After returning home with the results, I used the free software package called Snuffler to join together and edge match all the squares surveyed this year. This plot is shown below:
Click on the plot to see a larger image. It is clear from the plot that the equipment is still working well, with the squares joining together perfectly. There are clear targets for evaluation, which we can discuss at the upcoming barbeque.