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Module 8 Demonstration of airborne scanner applications |
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These four images of the same site show the potential of airborne scanning. Click on an image to see a larger picture. | ||||||
| (1) This casiTM image has 12 bands of data, recording radiance in the visible and near infrared parts of the spectrum. In this example, radiance recorded in red, green and blue wavelengths is shown in those colours so that landscape features appear much as we would recognise them from the air. The image was recorded in August 1998 and covers a 1 km square, composed of rows and columns of 3 m square pixels. |
(Figure 1) |
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| (2) The above shaded aspect relief image is derived from a surface elevation model interpolated from spot height information collected by the LIDAR instrument. In this example the Sun is casting shadows on the south-east facing side of landscape features, such as woodland blocks, hedgerows and farm buildings. Notice how clearly these features stand out from the surrounding landscape. The LIDAR data can be used to establish the height of trees, hedges and buildings, and to show surface slope, aspect, and elevation. |
(Figure 2) |
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| (3) The above example shows a very detailed height profile of a 60 metre length of hedgerow. The contours shown are for elevation above sea level, and are at a 50 cm interval. The field surveyors recorded the hedge as 2-3 metres high, of mixed species composition, lacking obvious signs of management, yet still stockproof. From the LIDAR data it would appear that the hedge is indeed complete, at a height of around 3.5 metres, but with several trees present which range in height between 6 and 12 metres. |
(Figure 3) |
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(4) The casiTM and LIDAR data sets can be integrated to generate a multi-dimensional view of our countryside, allowing more information to be attained than by the use of each data source alone. In the above 3-dimensional representation, notice how clearly woodlands can be identified in the landscape, but how individual trees appear pyramidal due to the height interpolation process using the LIDAR point sample data. |
(Figure 4) |
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