NDAC Orthophoto

Over the last week the NDAC model grew a little bit, with the BaE 146 aircraft joining the overall site (Thanks Marcus!). An updated model will be published soon.

GPS Data

Other progress included adding GPS data, using Google Earth to glean the latitude and longitude of the various buoys that mark the attractions. Depth was taken from the NDAC site guide, and whilst this method is not perfect it does save a four hour drive to measure them precisely.

The Orthophoto

NDAC Orthophoto thumbnail

The biggest step forward was the generation of the orthophoto of the site. Orthophotos are a 1:1 2D view of a model, using the individual images (nearly 10,000 now) to build a single, massive image. In this case, the resolution is 1.2mm per pixel, generating a 13.5Gb TIFF image. It goes without saying that this file is not really suitable for online viewing, so here is a downgraded example:-

So we have the whole site in a single 2D view with an amazing level of detail. The following images are 1:1 crops from a TIFF image. Each pixel represents 5mm.

Colour Shifts

As you look around the image, the colours shift quite dramatically. When we started this project mapping the site was not really considered feasible, and most dives were simply to test a new technique or trial a bit of kit. An example of this is the Wessex helicopter: this was the first trial of the Orcalight Sea Wolf light.

So we see some colour shifts, most extreme when natural light only was used. Knowing what we do now, everything would have been shot with consistent lighting…but that’s hindsight.

Land Rover:

The Abbott Self Propelled Gun

The Wessex Rotor Head

An Ironing Board

Left over from the world record underwater ironing days.


Not sure why vandalism is seen as part of diving?

BaE 146