39 resultados para Radio coverage
em Publishing Network for Geoscientific
Resumo:
The dataset contains a cropland percent coverage map for Africa created through the combination of five existing land cover products: GLC-2000, MODIS Land Cover, GlobCover, MODIS Crop Likelihood and AfriCover. A synergy map was created in which the products are ranked by experts, which reflects the likelihood or probability that a given pixel is cropland. The cropland map was calibrated with national and sub-national crop statistics using a novel approach. Preliminary validation of the map was undertaken. The resulting cropland map has an accuracy of 83%, which is higher than the accuracy of any of the individual maps. The cropland percent coverage map for Africa is available for overlay on Google Earth or for download at http://agriculture.geo-wiki.org.
Resumo:
During two Antarctic field seasons, western Dronning Maud Land and eastern Coats Land were covered by airborne radio-echo sounding surveys, conducted in combination with magnetic and gravity measurements along the 50 NW-SE-directed tracks, totaling about 11200 km and spaced 20 km apart. The data were collected in analogue form and then processed to compile ice surface, ice thickness and bedrock topography maps in I : 2 500 000 scale which gave a new and/or more detailed information on the region than previous compilations. The maps show that western Dronning Maud Land is dominated by a large mountainous area with altitudes up to 2800 m including rock outcrops of Annandagstoppane, Borgmassivet, Kirwanveggen and Heimefrontfjella. Upland terrains of Vestfjella and Mannefallknausane have an isolated position and are surrounded by a plain with bedrock depressions of 600 m deep below sea level. A narrow strip of north-eastern Coats Land studied by radio-echo soundings exhibits a smooth subice relief with altitudes close to sea level. The structural style of bedrock topography was mostly determined by extensional tectonics.
