Digital maps provide altitude data for regions on Earth. The amount of data to be processed increases with O(n
) complexity when resolution detail of the map in use increases. As the storage and processing capacity of handheld mobile devices are very limited compared to regular computer systems, the amount of data that can be stored in the device memory is also much less than of more complex computer systems. DTED Level 0 data provides approximately 1km resolution of elevation data which requires smaller storage space. The points in between the sampled points can be interpolated making use of the interpolation algorithms, with the addition of two sets of extra points whose coordinates are determined according to the existing sample points.