Error analysis of a heterodyne submillimeter sounder for the detection of stratospheric trace gases

Heterodyne submillimeter detection techniques represent an important develo pment in the field of remote sensing of atmospheric composition. The disclo sure of this wavelength region by new low-noise detectors and multichannel high-resolution spectrometers leads to expectations of improved accuracy an d vertical resolution of the vertical composition profiles derived from the se measurements. Because of the low-noise levels of newly developed receive rs, special care is required to ensure that fundamental Limitations of the components used do not contribute to systematic errors exceeding the random errors. Operated in an upward-looking geometry, the sensitivity of the ret rieval algorithm to noise and instrumental errors can be rather high, and h ence instrumental limitations could induce large uncertainties in the deriv ed atmospheric information. Instrumental uncertainties typical for a passiv e heterodyne sounder are quantified, and their effects on the accuracy of t he derived vertical mixing ratio profiles are presented. (C) 2000 Optical S ociety of America. OCIS codes: 010.1280, 010.4950, 280.0280, 120.5630, 120. 6200, 040.2840.