Cassegrain configuration

Cassegrain configurationclick for a larger image
Cassegrain configuration

Cassegrain configuration

(kass -ĕ-grayn) One of the configurations in which a large reflecting telescope can be used. A small secondary mirror with a convex hyperboloid shape intercepts the beam of radiation before it reaches the prime focus of the primary mirror (see illustration). The secondary reflects the beam back down the tube, through a central hole in the primary mirror, to a focal point just behind it. This is the Cassegrain focus. It is more accessible than the prime focus and is incorporated into many reflecting telescopes, notably the Schmidt telescope and the Maksutov telescope.

References in periodicals archive ?
A few years later, Italian optical designer Massimo Riccardi worked Honders's system into the Cassegrain configuration found in today's astrographs.
The S-band feed is located at the prime focus of the main reflector; the X-band feed operates in a Cassegrain configuration.
The cassegrain configuration for the X-band portion of the antenna is an adaptation of a 17th century optical telescope design.
0 meter antenna reflector, subreflector, and an X-band radio frequency feed mounted in a cassegrain configuration.
For our night of observing it was set up in its "bent" Cassegrain configuration.
We have been unable to find any written records that address the condition of the reflecting surfaces of the three mirrors used in the Cassegrain configuration.
This has led to a need for shorter feeds for use in Cassegrain configurations.
Maksutovs in f/10 to f/16 Cassegrain configurations have been popular in the astronomy marketplace since Questar introduced its 311/42-inch model in the 1950s.