Calibration of the COBE FIRAS instrument

Abstract

view Abstract Citations (76) References (13) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Calibration of the COBE FIRAS Instrument Fixsen, D. J. ; Cheng, E. S. ; Cottingham, D. A. ; Eplee, R. E., Jr. ; Hewagama, T. ; Isaacman, R. B. ; Jensen, K. A. ; Mather, J. C. ; Massa, D. L. ; Meyer, S. S. ; Noerdlinger, P. D. ; Read, S. M. ; Rosen, L. P. ; Shafer, R. A. ; Trenholme, A. R. ; Weiss, R. ; Bennett, C. L. ; Boggess, N. W. ; Wilkinson, D. T. ; Wright, E. L. Abstract The FIRAS instrument on the COBE satellite was designed to accurately measure the spectrum of the cosmic microwave background radiation (CMBR) in the frequency range 1-95 cm^-1^ with an angular resolution of 7^deg^. We describe the calibration of this instrument, including the method of obtaining calibration data, reduction of data, the instrument model, fitting the model to the calibration data, and application of the resulting model solution to sky observations. The instrument model fits well for calibration data that resemble sky conditions. The method of propagating detector noise through the calibration process to yield a covariance matrix of the calibrated sky data is described. The final uncertainties are variable both in frequency and position, but for a typical calibrated sky 2.6^deg^ square pixel and 0.7 cm^-1^ spectral element the random detector noise limit is of order of a few times 10^-7^ ergs cm^-2^ s^-1^ sr^-1^ cm for 2-20 cm^-1^, and the difference between the sky and the best-fit cosmic blackbody can be measured with a gain uncertainty of less than 3%. Publication: The Astrophysical Journal Pub Date: January 1994 DOI: 10.1086/173577 Bibcode: 1994ApJ...420..457F Keywords: Background Radiation; Calibrating; Cosmic Background Explorer Satellite; Mathematical Models; Michelson Interferometers; Angular Resolution; Data Reduction; Error Analysis; Fourier Transformation; Pixels; Signal Processing; Signal To Noise Ratios; Astrophysics; COSMOLOGY: COSMIC MICROWAVE BACKGROUND; INSTRUMENTATION: SPECTROGRAPHS full text sources ADS |