Infrared Astronomy is a relatively new subject but it has already radically altered our ideas about astronomical sources. Recent progress in this subject is the result of improved detection techniques, particularly the use of detectors at liquid helium temperatures. Unfortunately, the terrestrial atmosphere greatly restricts Infrared astronomers by allowing them to detect radiation only in narrow transmission win dows and by presenting a foreground emission which limits the faintness of observable sources. It is only from aircraft or balloon altitudes that we can begin to observe faint sources over the complete range of wavelengths between the visible and the radio regions. Few such observations have yet been made and none from satellites, although the latter vehicle will offer complete freedom from atmospheric effects. New developments and intermediate steps will be required before the ultimate aim of flying in space can be achieved. It is not surprising therefore that the Fifth Eslab/Esrin Symposium should deal with this problem. This book contains the proceedings of the Symposium and faithfully records all discussions. The Symposium covered the present situation and future perspectives of IR techniques. International leaders in the field reviewed the results to date and the possible developments in telescope systems, detectors, cryogenics, filters, and interferometers. Individual con tributions were made by European and U. S. scientists in each of these fields.

Proceedings of the Fifth ESLAB/ESRIN Symposium, held in Noordwijk, The Netherlands, June 8-11, 1971

Inhalt

1. Results in Infrared Space Astronomy.- Review of Results in Infrared Space Astronomy.- 2. Systems for Space Research.- The NASA 91.5 cm Aperture Airborne Telescope.- A 32-cm Airborne Infrared Observatory.- Far-Infrared Observations of Celestial Objects by Balloon-Borne Telescope.- An Infrared Photometer for the Balloon-Borne Telescope Thisbe.- Measurements of the Atmospheric Background Emission Between 10 ? and 100 ?.- A Balloon-Borne Helium-Cooled Interferometer for Investigation of the Isotropic Submillimetre Background.- Infrared Rocket Astronomy.- An Interference Filter Radiometer with Cooled Optics and a Cooled PbS Detector for Rocket Application.- Infrared Interferometry from Satellites.- The Meteosat Dual-Channel Radiometer.- 3. Detectors.- Infrared Detectors. Survey of the Present State of the Art.- Liquid Helium-Cooled Bolometers.- A New Type of Helium-Cooled Bolometer.- Performance Tests of InSb and Ge Bolometers.- An Infrared Transducer for Space Applications.- Josephson Detection.- Astronomical Polarimetry at 5 and 10 ?.- Problems and Design of Black-Body References.- 4. Cryogenics.- Cooling Systems for Spaceborne Infrared Experiments.- Balloon-Borne Infrared Cryostats.- 5. Filters.- Survey of the Present State of Art of Infrared Filters.- Metallic Grid Filters.- New Narrow-Band Metallic Mesh Filters for the 50 ? Region.- High-Pass Filters for Far Infrared Astrophysical Investigation.- Filters for Far Infrared Astronomy.- Submillimetre and Millimetre Mapping Using Interference Filters.- 6. Interferometers.- Interferometric Spectrometry for Infrared Astronomy.- Far Infrared Broad Band Interferometry.- Rapid Scanning Michelson Interferometer.- Field Compensated Interferometer for Stellar Spectrometry.- A Sisam Interferometer and a Simple Michelson-Interferometer with Spherical Mirrors for Space Application.- Liquid Helium-Cooled Grating Monochromator.- One- and Two-Dimensional Computational Problems Associated with Interferometry.- Remarks on Infrared Technology and Spectroscopy in Astrophysics.- 7. General Discussion (directed by Prof. F. Kneubühl).