More than two years ago we published the last Pacific Islands GIS/RS Newsletter. Now, we have a new team and will publish in regular intervals again. During the last few years changes have happened in the world of GIS and RS application as new type of data is available and also new software and hardware to handle it.
Essential is the new quality of space borne image data where satellites like WorldView-1, GeoEye and WorldView-2 have increased their geo-accuracy due to more precise position capture during data recording through enhanced on board GPS and star tracker.
Also the spatial resolution of these optical range satellites has further increased just that this is not delivered outside US. The increased radiometric resolution allows better stratification of vegetation; data of WorldView-2 now covers eight spectral bands where three visible and one near infrared was the norm before.
The increase in data quality induced an increase in pre-processing needs of data to fully utilise the provided information.
Image data is in nowadays ortho-rectified, haze is removed through special software and atmospheric correction is applied utilising a digital elevation model to address the relief related atmospheric disturbances, which is essential for volcanic island countries surrounded by large areas of sea.
To provide Pacific users with such enhanced data the pan-sharpening process is carried out at SOPAC as it is not possible to improve already pan-sharpened image data in this way.The improved image quality results in an increased image utilisation for different applications. Here a shift is noticeable from just simple backdrops mainly for utilities to a range of different backdrop products from the same dataset.
The latter is used for vegetation and land cover mapping, where the interpreter toggles between the different backdrops during the image interpretation.
This newsletter and the following releases will again inform about the new image data not limited to optical range, the enhancement technics, the new application methods and hard ware or software development.
The team is happy to receive articles from Pacific island GIS and RS users as we want raise the information level within Pacific Island Countries.
Dr. Wolf Forstreuter
