Aerial Photos / Photogrammetry
The Survey Division is the contact agency for the Bureau of Engineering for obtaining aerial photos and photogrammetric maps. Although both aerial photos and photogrammetric maps involve taking photos from the air, they are distinguished from each other in that aerial photos are the actual photos of an area and a photogrammetric map is a map showing elevation contours and the outlines of physical features. They are also distinguished in their use. A photogrammetric map is generally used for design purposes, while an aerial photo is often taken when an overall picture is needed.
When a contract is let out to produce a photogrammetric map, the Survey Division is responsible for setting the aerial targets and establishing the control (coordinates and elevation) on them. Aerial targets allow the photogrammetrist to determine the elevations and distances on the map.
The Survey Division is responsible for the letting out the contract and the procurement of data for the Digital Ortho Imagery (DOI) project for the City of Los Angeles. In this project the entire City of Los Angeles including the city of San Fernando will be aerial photographed and Digital Orthophotos and a Digital Terrain Model (DTM) will be produced. The DTM will include 5 foot contour intervals over the entire area.
The Digital Orthophotos will show the physical features of the City including : building footprints, trees, roadways, streetlights etc. The results will then be utilized by the various departments in the city.
For Photogrammetric Services call : (213) 482 -7100