Global Mapper is a sophisticated GIS package which allows multiple datasets to be opened concurrently.
It has built in functionality for distance and area calculations, raster blending, feathering, spectral analysis and contrast adjustment, elevation querying, line of sight calculations, cut-and-fill volume calculations, as well as advanced capabilities like image rectification, contour generation from surface data, view shed analysis (including Fresnel) from surface data, terrain layer comparison (including differencing), and triangulation and gridding of 3D point data.
Repetitive tasks can be accomplished using the built in scripting language or comprehensive batch conversion functionality.
The software opens raster, vector, elevation, satellite and GEOTIFF data among others.
Aerial photography can be draped over the elevation data to give a 3d effect. Each layer of data can be viewed independently or jointly, blending from one to another with ease.
Typical features include: zoom, measurement, line of sight analysis, cross sections, 3d view option, flood projection analysis and a digitiser tool that enables you to edit existing features or create new areas, lines or points.