Feasibility demonstration of a high performance compact telescope

In order to demonstrate the feasibility of a compact telescope with both wi de field of view and high resolution, a demonstration model has been built and tested at CNES. This 1.08-m focal length, f/6 three-mirror anastigmat t elescope has excellent image quality over its whole 8.4 degrees x 1.4 degre es field of view: modulation transfer function is about 0.54 @ 77 1p.mm(-1) (detector Nyquist frequency). The focal plane comprises two channels, one panchromatic with 24 000 pixels and one multispectral with 12 000 pixels in each of its 3 spectral bands. The whole telescope (mirrors, structure, baf fles and focal plane) weighs less than 45 kg. The conception has been done in order to favor structure simplicity and short alignment time while retai ning high stability and good image quality. The first part of this paper wi ll focus on the instrument design, and the second part on the manufacturing and test results. (C) 2000 Elsevier Science Ltd. All rights reserved.