No Man’s Friend

Friday and Saturday saw us return to Six Acres / Cartway / Broomhall Farm.  One day we will have to decide what to call the site!  Six Acres is the name of the enclosed piece of pasture where the original survey was undertaken, Cartway is the field to the east of Six Acres, and No Man’s Friend is the field to the south.  All the fields are part of Broomhall Farm.

Our aim over these two days was to complete the area we had gridded out in No Man’s Friend.  This included the partial grid left incomplete last week when the rain drove us away, a grid square from May that had suffered from the dreaded “frozen sensor syndrome”, and a number of other squares, largely partials.  The hope was that we would find the north-south ditch seen so clearly within Six Acres.

Weather and mud made life difficult.  Although it was dry — most of the time — the wet field surface adhered to the wheels like glue, necessitating frequent cleaning of the wheels with a trowel and washing of the odometer gears with water and a washing-up brush.  Unfortunately, the sensors froze twice on Friday, leading to us having to repeat grids, one of which was already the repeat from May!  Thanks to the sterling efforts of Jon Wimhurst, Jim West, and Clare Lewis, we did manage to complete all the grids in No Man’s Friend.  The data processing took some time, as dealing with partials that include wheel-spinning sections is fiddly.  I have created another crude mash-up, which is posted below.  Remember, the location of the surveys on Google Earth is guess work in these, unlike the previous surveys elsewhere. (We’ll be able to place them precisely when I have the coordinate transformations sorted out.)

The Six Acres survey as of 19th October 2013.

The Six Acres survey as of 19th October 2013.

For those of you who are worrying that you cannot see anything in No Man’s Friend — please don’t worry,  I cannot see anything either.  I’m really stunned that nothing shows, given what we can see north of the fence line.  As always with geophysical data “absence of evidence is not evidence of absence.”  There are four possibilities:

  1. for some reason the ditch is not magnetically enhanced at that point and thus invisible to the machine;
  2. the ditch has been ploughed out;
  3. the ditch stops in Six Acres;
  4. the ditch turns and follows the hedge line where undergrowth and metal fencing makes it impossible to see.

None of these explanations are 100% satisfactory and I remain bemused by the results.

Our next aim is to undertake the survey of a line of grid squares in the fields to the west of Six Acres.  Unfortunately, the weather looks decidedly against us.  Fingers crossed that we have the chance to do those before the fields are cultivated.

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