Unlike a conventional aerial photograph, accurate measurements can be made on the orthophoto map. These maps are well suited for detail planning and analysis of what exists on the ground. The orthophoto maps cover all metropolitan and peri-urban areas and growth areas. These sheets are available as ammonia-developed prints on either paper or opaque film or as bromide prints on photographic paper. Most USGS topographic maps use brown contours to show the shape and elevation of the terrain.
Contour intervals vary, depending mainly on the type of terrain and the scale of the map.
The maps show and name prominent natural and cultural features. Such detail is useful for engineering, local area planning, and recreational purposes. They cover larger areas and are used in land management and planning. Second you need a good graphics editor. Adobe Photoshop is the best graphics editor available and also expensive.