Ballistic camera

Ballistic cameras are measuring cameras for determining the orbit of ballistic missiles ( projectiles , sounding rockets and other rockets ), balloon probes and artificial earth satellites . In terms of design, they are related to aerial cameras and, like these, are manufactured by geodesy and photogrammetry production companies.

A ballistic camera must be swiveling quickly, but it must be very stable and also be able to precisely record fast movements, which requires a time measurement of better than 0.001 seconds. The lens should be bright but have as little distortion as possible . For the photo plates of around 20 × 20 cm that were customary in the past, this resulted in focal lengths between 25 and 75 cm and aperture ratios of around 1: 2.5 or 1: 4.

The mount is generally azimuthal - similar to a theodolite - and mostly equipped with partial circles.

The most widely used camera is the BC-4 from Wild-Heerbrugg (now Leica), which was available in two versions with a 30 cm and 45 cm focal length. About a dozen of the long-focal length version suitable as a satellite camera were used to measure the first world network around 1970 (see world network of satellite triangulation ).

Since the photographic glass plates are relatively expensive and many earlier producers have stopped their production, the conversion of ballistic cameras to digital image recorders ( CCD etc.) is obvious, but developments with shorter focal lengths also make sense.

See also:

• Satellite photogrammetry , cosmic geodesy
• Astrometry , orbit determination , ballistics