A new superconduction tunnel-junction receiver is being completed by the PI for use in ground-based measurements of stratospheric trace gases. This receiver will operate in the 260-280 GHz range with high sensitivity (low receiver noise temperature). A separate 'back-end' spectrometer for this new receiver is not currently available. This proposal seeks funding for a commercially made dual acousto-opticspectrometer in a single economical package, having two simultaneously usable sections with different resolution and total bandpass. This spectrometer would allow a flexible choice of high or low altitude mixing ratio retrievals, or a combined mid-mesospheric to low stratospheric coverage of appropriate species, and be fully portable in keeping with the intended program of field measurements in which the SIS receiver will be employed. The acquisition of a new spectrometer, in addition to the aging filter-bank spectrometer now on hand, will allow flexible deployment of both receivers - e.g., one dedicated for 1 to 2 years of round-the-year observations at the South Pole or another remote site, while the other is used at one or more other field sites in connection with regular observations and the UARS correlative measurements program.
