Context and objectives
Land use maps at a scale of 1:200.000 exist for the whole of Costa Rica. They were produced in 1985 from Landsat-TM images and aerial photographs. Given the frequent cloud cover, regular updating of those maps via optical satellite data is problematic. The objective of the study is to develop a procedure for producing land cover maps.
Expected scientific results
A procedure has been developed for producing land cover maps and an associated measure of accuracy. It consists of calibration, resampling, filtering, segmentation, principal component transformation and supervised classification of multitemporal radar images. As input to this processing chain any number of SAR.PRI images or derived texture images can be used. The output consists of a land cover map and an accuracy assessment. The procedure has been applied to a series of 4 SAR images, which yielded a map with an overall accuracy of 78 %. The high precision with which the large banana plantations can be mapped is most interesting, both for its economic importance as for environmental monitoring.
By combining this map with the land cover map of 1986 it is possible to detect the changes over the period 1986-1995.