Aerial Photography: Interpretation Page 8 of 8 Approach taken There is no one particular approach to image interpretation. Specialised image products and equipment will partly influence how the task of interpretation is undertaken. Aside from these factors it is the goals of the task that will determine the process employed. Many applications of image interpretation require the delineation of units on the images. Mapping of land use, soil types etc. would be an example of this where the interpreter needs to outline boundaries between areas. This type of task can be problematic if the boundary is not a discrete edge or where there is gradation from one type of area to another and this is common with natural phenomena such as soils and vegetation. It is advisable to delineate the most contrasting features first and work from the general to the specific. An example of this would be to separate the urban areas from water and agriculture before looking at more detailed categories EXERCISE As with any fieldwork activity our background information initially comes from maps. The amount of information available however is dependent upon the scale of the map and the amount of detail we require. Compare the following maps of Buttermere, Cumbria and particularly the amount of details available on each. CLICK ON THUMBNAILS TO SEE THE IMAGES FULL SIZE 1:10,000 1:25,000 1:50,000 1:100,000 (Maps reproduced courtesy of Ordinance Survey ) This use of scale also applies when interpreting aerial photographs. Compare the amount of detail shown on each aerial photograph below: 1:10,000 1:25,000 1:50,000 1:100,000 (Photographs repoduced courtesty of Getmapping) In order to ensure that the aerial photograph is best suited to our needs the most appropriate scale should be chosen. From example a 1:100,000 scale gives a broad indication of the whole area, whereas the 1:10,000 gives a clearer indication of the actual terrain. Now attempt your own aerial photography interpretation of this area. From this 1:25,000 map of Buttermere, Cumbria identify the following features 1. Tarn 2. Lake 3. Woodland 4. River 5. Footpaths THIS EXERCISE WILL OPEN IN A NEW WINDOW The next sections looks at photograph preparation and viewing: Aerial Photography: Image preparation and viewing   | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | Page 8 of 8