We decided to survey two 15m squares that would cover the ditch and any possible features up the slope and on the upper plateau.
The setting out took most of our time but once this was completed the survey of the two squares was done quite quickly.
Unfortunately at this time I had not worked out how to download the data but by the weekend it was downloaded and what a surprise I got.
Below are the two grids superimposed on the plan. This shows the ditch continuing and then coming to an abrupt end. There are also two parallel lines on the right of the plot which are each side of trench 4.
The grids were then processed as below. This shows even more clearly the ditch termination and the possibility of a building on the right.