240 aPPenDiCes
Photogrammetry. The science of obtaining accurate measurements from photographs; map-
ping or surveying by photographic methods.
Pictorial symbol. A symbol on a map that is a small picture of some object. Normally, these
symbols imitate the object or distribution being mapped. Also called “mimetic sym-
bols” or “pictographs.”
Pie chart. A circular symbol divided into sectors to indicate proportions of a total value.
Often combined with proportional circles. Also called “pie graph,” “segmented cir-
cle,” or “sectored circle.”