Georeferencing specimens by combining digitized maps with SRTM digital elevation data and satellite images: a Bornean case study

For numerous scientific purposes collection records need to be georeferenced. Although the geographic coordinates of many of the collection localities are available in gazetteers, especially collections from tropical areas of the world are still not georeferenced. In an attempt to georeference these localities for Indonesian Borneo we used digitized old maps which were georegistered with SRTM digital elevation data, and Landsat 7- and JERS-1 SAR radar satellite images. This enabled us to georeference 2 577 additional collections from Indonesian Borneo, belonging to 1 744 taxa, which were collected at 134 previously not georeferenced localities. This applied methodology enables researchers to georeference their historical collections for biodiversity, biogeographical, and global climate change impact studies.