REFERENCE : CHIEF RRY
Fig. 3.58. Spot-diagrams for the Hawkins-Linfoot monocentric Cassegrain of Fig. 3.57, aperture 400 mm, f/3.0 - f/6.0
4 aspherics eiS
Fig. 3.60. Baker-Nunn camera, designed for satellite tracking, aperture 508 mm, f/1.0
is considered as two identical halves disposed about the central symmetry plane, each half can be seen as a refinement of the Hawkins-Linfoot corrector in which the powered surface is separated into two aspheric surfaces by an airspace. Each half is therefore like an achromatic Schmidt plate with power added. The symmetrical doubling of the system halves the asphericities and produces complete symmetry to the stop, thereby eliminating asymmetries of the oblique pencils. The d80 energy concentration diameter is within 20^m for a wavelength band from the near UV to the far IR even at the edge of the field strip of 5° x 30°.
The Baker-Nunn camera has been included here as one of the "SuperSchmidt" systems to be compared with the Baker Meteor Camera above (Fig. 3.59). However, generically, the Baker-Nunn system is also related to the Houghton-type lens correctors dealt with below in this section.
Was this article helpful?