As we described in the ‘Droughts and Flights’ blog post Doreen Boyd, Quinton Carroll (Cambridgeshire County Archaeologist) and Anthony Beck submitted a special request to the NERC ARSF team for flights over Diddington and RAC due to the drought conditions. I’m delighted to say that this application was partially successful. Late afternoon on Monday we were informed by Gary Llewellyn, from the NERC ARSF team, that they would fly the LiDAR and the Eagle and HAWK hyperspectral scanners over Diddington the next day!

We were obviously delighted with this result: many thank to Gary and NERC for providing this opportunity. This meant Doreen Boyd, David Stott and Anthony Beck dropped everything to get to Diddington for the Tuesday to take concurrent spectro-radiometry. Concurrent, or near concurrent, spectro-radiometry readings will allow David to understand and correct for signal attenuation between the object (the ground) and the sensor (the spectro-radiometer or the sensor on the plane) due to atmospheric anomalies. In theory the spectro-radiometer produces a ‘true’ reading and the response from the sensor on the plane produces an ‘attenuated’ reading. ATCOR-4 atmospheric correction algorithm will be applied to the data as part of the post-processing.

Atmospheric Interactions

We arrived onsite at approximately 12:30, after signing in with the Thornhill Estate we saw the NERC plane finish it’s transects.

“the plane boss the plane!”: NERC’s plane over Diddington. Re-used under a creative commons licence from Archaeobobalist.

We then took reference spectroradiometry readings from two locations. One at the West of the area on an homogeneous and clean concrete platform and another at the East of the area on a homogeneous and clean tarmac area.

Ground control to Major Tom: taking ground spectro-radiometry measurements. Re-used under a creative commons licence from Archaeobobalist.

We then took another transect of height, spectro-radiometry and SPAD readings across an archaeological feature in the wheat. We’re looking forward to doing exactly the same thing for the CASI survey from the Environment Agency in the very near future. We’re hoping that the area is inundated with rain so that we can capture the spectral impact of a pre and post rainfall event on extant archaeological features.