Every photograph in the collection is part of a 'flight,' or mission. During the 20th century, producers of aerial photography adopted a convention by which each corporation would prefix their flight codes with a corporate identifier. The USDA altered this practice by designating unique three letter codes for counties for which it produced photographs (we have a map of California counties and their codes). As a result, we are able to easily group photographs together, both intellectually and on the shelf.
| Flight Code | Description |
|---|---|
| AMI | Aerial Map Industries. Flight codes typically followed by a county and a 2-digit year, ie: AMI-SBD-86 |
| AN | Mark Hurd. Typically followed by a 2-letter accession code |
| ASCS | The USDA's Agricultural Stabilization and Conservation Service. These flights are typically older than USDA flights with 3-letter county codes |
| C | Fairchild Aerial Surveys California office. C- flights are chronological, with C-1 flown in 1927 and C-25000 in 1965. |
| CAS | Cartwright Aerial Surveys |
| CH2M | CH2M Hill Engineering. Primarily photos of rice-growing regions of California |
| EAG | Eagle Aerial Imaging |
| GS | Golden State Aerial Surveys |
| GS | US Geological Survey |
| HA, HB, HO | Mark Hurd. Followed by a 2-letter sequential code |
| NY | Fairchild Aerial Surveys New York office. |
| PAI | Pacific Aerial Industries |
| PW | Pacific Western Aerial Surveys |
| TA | Mark Hurd. Typically followed by a 2-letter accession code |
| TG | Teledyne Geotronics |
| USDA | Large flights created by the United States Department of Agriculture. Primarily smaller scale and of a later vintage than USDA county-coded flights |
| WAS | Watson Aerial Services |
| YY-### | As in 'year.' Many NASA flights have numeric flight codes beginning with a two-digit year followed by a 2 digit accession number. Actual flight codes are much longer, ie: 73-055-01079 |
