We’ve used all sorts of things as ground control markers in aerial survey before – indeed, if sufficiently obvious points exist, they can be georeferenced. Where this is not possible, I’ve used orange bivouac bags and a combination of tarpaulins and duct tape. These usually only lasted a few days to weeks, and then were disposed of. This got me thinking – I wonder if I could find a more hard-wearing solution. I couldn’t – so I designed some, and my colleague Hayley Goodes made them. I think they are excellent!
They are white-orange Battenberg design cotton flags, approximately 150cm square, and black gaffer tape can be placed as roman numerals across them to identify them if required. They have brass eyelets for pegging down or otherwise securing, are fully hemmed, and can be machine washed.
Hayley deserves most of the credit as she did all the hard work.