Coastline changes can be
analysed approximately forty years back in time based on different
remote sensing data sets. Recently declassified US spy satellite images
provide a unique data source for information about the stability of
coastal environments. When combined with modern high resolution
satellite images, long time series of coastal development can be
analysed. The processing of US spy data is relatively complex, but GRAS
has expertise in processing these data sets for coastal monitoring in
many parts of the world.
Overview analyses can be done using a combination of US Spy data and
Landsat data. This will allow an analysis of coastline changes with 4-5
images in the period 1960-2005 and an accuracy of app. 15 metres.
Higher accuracies can be obtained by combining the spy data with SPOT
which is available in the period 1986 to present. In this way
accuracies can be within 5 metres. For detailed studies of recent
phenomena, very high resolution data can be used to map coastline
changes at extremely high accuracies. Using QuickBird data with a
spatial resolution of 60 cm, the results are comparable to aerial
photography.
Applications
Coastline monitoring is an
important step in many coastal engineering projects such as harbour
construction and for coastal protection. Furthermore, coastline change
detection is an important environmental parameter, i.e. in connection
with erosion from storm impact or human disturbance.