Getmapping aerial photography is being used to help create and update Harvey Maps, which are enthusiastically endorsed by mountaineers, walkers, cyclists and orienteers.
Getmapping also provides a WMS feed of its latest UK aerial photography to enable Harvey Maps to detect change so that its maps can be kept up to date. Getmapping captures aerial photography with a range of high resolution large format digital cameras. The cameras capture frames with a large degree of vertical overlap so that images can be orthorectified to correct the distortions due to topographic relief, or camera orientation during flight. Image resolution varies according to requirements. Most urban imagery is captured with each pixel equivalent to 12.5cm ground sampled distance (GSD). Rural and mountain areas are generally captured at 25cm GSD.
Harvey Maps has always prided itself on the fact that its walking and other recreational maps are made using sound map making techniques and then checked by a team of experienced field surveyors who are themselves enthusiastic walkers. As a result Harvey Maps are renowned for their accuracy, clarity and practicality with many available in tough waterproof polyethylene. Many of these maps are now available in digital format, for example on an SD card for use with the Satmap Active 10 GPS receiver.
“We feed stereo imagery from Getmapping in to our photogrammetric process. Use of this imagery produces a virtual model of the ground from which we then create a base map. The data is very accurate and enables us to record all the features, create spot heights and contours, which help describe the shape of the landscape on a two dimensional map. The WMS feed provides us with online access to all of Getmapping’s most up to date imagery. This is very useful for detecting change so we can update our maps or get new features field checked by our surveyors.” Robin Harvey, co-founder, Harvey Maps