topic Optimising ASTER dem for viewshed in Data Management Questions https://community.esri.com/t5/data-management-questions/optimising-aster-dem-for-viewshed/m-p/4665#M331 <HTML><HEAD></HEAD><BODY><SPAN>I want to calculate a viewshed based on ASTER DEM data. Unfortunately, the data contain a lot of artefacts in this region, most of which are caused by poor coverage. Even (or especially) in flat areas, the DEM shows a rather cratery landscape with lots of small holes. </SPAN><BR /><SPAN>Since the ASTER data come with a quality assessment file, I wonder whether I could use this to optimise the dem for my viewshed. The num-file indicates the number of readings, which the elevation of the respective pixel in the DEM is based on. Where there were no readings, the value was taken from SRTM-data (which seem to cause a lot of these craters). This is indicated in the NUM-file by value -1. </SPAN><BR /><SPAN>Would it be possible to interpolate the DEM and give the grid cells with more readings a higher weight than those with few readings or SRTM-values? Some sort of weighted neighbourhood statistics?!</SPAN></BODY></HTML> Thu, 03 Feb 2011 10:22:31 GMT JorisCoolen 2011-02-03T10:22:31Z Optimising ASTER dem for viewshed https://community.esri.com/t5/data-management-questions/optimising-aster-dem-for-viewshed/m-p/4665#M331 <HTML><HEAD></HEAD><BODY><SPAN>I want to calculate a viewshed based on ASTER DEM data. Unfortunately, the data contain a lot of artefacts in this region, most of which are caused by poor coverage. Even (or especially) in flat areas, the DEM shows a rather cratery landscape with lots of small holes. </SPAN><BR /><SPAN>Since the ASTER data come with a quality assessment file, I wonder whether I could use this to optimise the dem for my viewshed. The num-file indicates the number of readings, which the elevation of the respective pixel in the DEM is based on. Where there were no readings, the value was taken from SRTM-data (which seem to cause a lot of these craters). This is indicated in the NUM-file by value -1. </SPAN><BR /><SPAN>Would it be possible to interpolate the DEM and give the grid cells with more readings a higher weight than those with few readings or SRTM-values? Some sort of weighted neighbourhood statistics?!</SPAN></BODY></HTML> Thu, 03 Feb 2011 10:22:31 GMT https://community.esri.com/t5/data-management-questions/optimising-aster-dem-for-viewshed/m-p/4665#M331 JorisCoolen 2011-02-03T10:22:31Z