Aerial photographs are vertical images (straight down) with stereo pairs for nearly all flights. Each flight record describes:
- Geographic extent of the flight
- Altitude of aircraft, scale of the resulting images
- Format and other important data
- See What is an Aerial Photograph?
Types of photos:
- Black & White - Good contrast and detail.
- Color - Sometimes easier to identify familiar objects using the color. Earliest color photos are from 1973.
- Color-Infrared - Shows landscape features that otherwise aren't very clear. See Understanding Color Infrared (CIR) Aerial Photography
What is scale?
- Scale is the ratio between the size of the object in the photo compared to the actual size of the object, indicated by: 1:4200, 1:7200, etc. The smaller the number after the colon, the closer to the ground the picture was taken.
- For examples, see UC Santa Barbara's explanation of Aerial Photography Scale
What can you see?
- Larger features (e.g. shores, mountains, the larger rivers, etc.) If the scale is under 1:15,000, possibly roads, parks, individual buildings, etc.
- Sequences of aerials of the same area
- See Introduction to Aerial Photo Interpretation
What can't you see?
- Small features if scale is over 1:15,000
- Buildings and structures that might be obstructed by trees