The Giotto Halley multicolor camera
Abstract
The Halley Multicolor Camera (HMC) is a Ritchey-Chretien type Cassegrain telescope (1000 mm focal length) with CCD imagers in the focal plane. It is suspended in a revolving mount so that the center of its field of view can be moved freely in a half plane that contains the spin axis of the spacecraft. Together with the spinning motion of the spacecraft, this mobility enables the HMC to image any part of the whole 4 pi solid angle of the sky. The line-scan imaging technique uses the spacecraft/s spin for one dimension and the length of the line for the other dimension of the image. Four line sensors with filters of different color bands take images almost simultaneously. Onboard electronics controlled by three microprocessors operate the camera almost autonomously. The image of the comet will be sought at the beginning of the encounter operations. Having found it, the camera will switch to the imaging mode. The contents of the images are to be telemetered to ground in sections and at the same time used onboard to update the parameters that describe the spacecraft/s trajectory relative to the cometary nucleus. With this information, the HMC/s field of view will be able to track the center of the comet/s image.
- Publication:
-
The Giotto Mission: Its Scientific Investigations
- Pub Date:
- March 1986
- Bibcode:
- 1986gmis.rept..149S
- Keywords:
-
- Astronomical Photography;
- Color Photography;
- Giotto Mission;
- Halley'S Comet;
- Cassegrain Optics;
- Charge Coupled Devices;
- Field Of View;
- Focal Plane Devices;
- Spaceborne Telescopes;
- Instrumentation and Photography