City of Los Angeles, CA (2000)

HJW was selected to prepare over 2000 digital orthophotos covering the City of Los Angeles. Black and white aerial photography was acquired at a scale of 1:7200 (1”= 600’). The photography was scanned at a resolution of 20 microns (1270 dpi) for the production of orthophotos with a 0.5’ pixel size. HJW compiled 5’ contours, breaklines and mass points, which were used to prepare a digital terrain model. The DTM supported the production of 1” = 100’ scale orthophotos meeting National Map Accuracy Standards.

For this project, HJW paid special attention to the City’s transformation into a new mapping datum. The City’s existing map sheet layout, in the old datum, had to be converted into the new datum with careful consideration for resulting rotations. HJW rose to the occasion and met their needs.