Archives for posts tagged ‘testing’

Optical Calibration Targets

Optical Calibrations Targets (via BLDGBLG). “There are dozens of aerial photo calibration targets across the USA,” theĀ Center for Land Use InterpretationĀ reports, “curious land-based two-dimensional optical artifacts used for the development of aerial photography and aircraft. They were made mostly in the 1950s and 1960s, though some apparently later than that, and many are still in […]