Optimization of Topographic Map Color Schemes for Diverse Lighting Environments

One of the essential requirements for Defence Topographic Maps (DTM) is ensuring their legibility under various lighting conditions, including low light and nighttime environments. Consequently, when designing legends for military maps, including DTMs, it is necessary to consider readability under different lighting conditions. The map content is defined by the NATO standard; however, its color variants can be adjusted within printing standards for defence geospatial products allowing optimization of readability. There are two main challenges: first, how to verify the legibility of a given color variant under all lighting conditions, and second, how to objectively determine this legibility. Precise measurement of spectral reflection of used colors in the DTM under various lights allows to express the contrast between base and drawing colour. Then the optimal color schema for DTM can be determined.