Those are swaths that the SRTM was unable to survey before its mission ended. There are only a few of them and luckily they're all inside the US where there is

Those are swaths that the SRTM was unable to survey before its mission ended. There are only a few of them and luckily they're all inside the US where there is already higher quality elevation data available from the USGS to fill them in. http://en.wikipedia.org/wiki/Shuttle_Radar_Topography_Mission http://en.wikipedia.org/wiki/Shuttle_Radar_Topography_Missio...