Drone mapping services in Dawlish

No stretch of railway in the country is better known for its exposure than the one running along the front here, and the engineering response to that has been a sustained programme of sea wall and cliff work. Infrastructure of that kind is a natural fit for aerial capture: long, thin, hard to get at from the ground, and changing measurably between visits.

A corridor along a sea wall is flown as a strip rather than a block, with heavier overlap to hold the strip together and oblique passes to record the face of the wall as well as the deck. Flying near an operational railway is arranged with whoever controls the line, and that arrangement comes before a date is agreed.

The red sandstone cliffs either side of the town are actively weathering, and a cliff face is the clearest example there is of something a straight down grid cannot record. A vertical or overhanging face is invisible from directly above; it needs angled passes flown at a standoff distance, from several heights, to build a surface.

That is standard practice and it is worth stating at quoting stage, because a client expecting a cliff survey to be the same flight as a field survey is expecting the wrong thing. Cliff work takes longer in the air and produces a heavier point cloud at the end of it.

Everything at the waterline is timed to the tide, and on this coast the swell matters too. A low water flight gets the wall footing, the apron and the beach; a high water flight gets none of them. White water and spray across the frame also degrade matching, so a big sea is a reason to move a date rather than push on.

The note supplied with a coastal job records tide state and sea conditions at capture, for the same reason it records cloud cover: somebody comparing two dates later needs to know whether a change is erosion or just a different tide.

Away from the sea wall, Dawlish is a Victorian and Edwardian resort town with a small stream running through the middle of it and steep ground rising quickly behind. Development sites here are mostly small and on the higher ground, and they fly easily compared with the coast.

Base is twenty five minutes up the coast road, so combining a coastal strip and an inland plot into one visit is realistic when both are ready.

The sand spit at the mouth of the estuary is one of the more dynamic pieces of coast in Devon, and it changes shape without anyone doing anything to it. Where a client wants that measured, the method is the same as for cliffs: identical flights at intervals, processed identically, compared as surfaces rather than as pictures.

The cliff-top ground behind the town carries a large amount of bungalow and estate development that takes wind straight off the sea. Sites up there are simple to fly on a calm day and not worth attempting on a rough one, which is more a scheduling point than a technical one.