Brad Gom

Preliminary design of FTS-2: an imaging Fourier transform spectrometer for SCUBA-2

We present the preliminary design of FTS-2, an imaging Fourier transform spectrometer (IFTS) for use with SCUBA-2, the second generation, wide-field, submillimetre camera currently under development for the James Clerk Maxwell Telescope (JCMT). This system, which is planned for operation at the start of 2007, will provide simultaneous broadband spectral imaging across both the 850 and 450 μm bands with variable resolution ranging from resolving powers of R ~10 to 5000. The spectrometer uses a folded Mach-Zehnder configuration and novel intensity beam dividers. The mechanical and optical design of FTS-2 as of the Critical Design Review stage of the project are discussed, along with the interfaces with SCUBA-2 and the JCMT.

Data processing pipeline for a time-sampled imaging Fourier transform spectrometer

Imaging Fourier transform spectrometers (IFTS) are becoming the preferred systems for remote sensing spectral imaging applications because of their ability to provide, simultaneously, both high spatial and spectral resolution images of a scene. IFTS can be operated in either step-and-integrate or rapid-scan modes, where it is common practice to sample interferograms at equal optical path difference intervals. The step-and-integrate mode requires a translation stage with fast and precise point-to-point motion and additional external trigger circuitry for the detector focal plane array (FPA), and produces uniformly position-sampled interferograms which can be analyzed using standard FFT routines. In the rapid-scan mode, the translation stage is continuously moving and interferograms are often acquired at the frame-rate of the FPA. Since all translation stages have associated velocity errors, the resulting interferograms are sampled at non-uniform intervals of optical path difference, which requires more sophisticated analysis. This paper discusses the processing pipeline which is being developed for the analysis of the non-uniform rapid-scan data produced by the Herschel/SPIRE IFTS.

SCUBA-2 imaging Fourier transform spectrometer

We present the conceptual design of an imaging Fourier transform spectrometer (IFTS) for use with SCUBA-2, the second generation, wide-field, submillimeter camera currently under development for the James Clerk Maxwell Telescope (JCMT). This system, which is planned for operation in 2006, will provide simultaneous, broadband, intermediate spectral resolution imaging across both the 850 and 450 µm bands. The spectrometer will offer variable resolution with resolving powers ranging from R ~10 to 5000. When operated at low resolution, the IFTS will provide continuum measurements, well suited to spectral index mapping of molecular clouds, as well as bright nearby galaxies. The IFTS uses a folded Mach-Zehnder configuration and novel intensity beamdividers. The preliminary design, projected telescope performance and scientific impact of the IFTS are discussed. The preliminary design, novel observing modes, projected telescope performance and scientific impact of the IFTS are discussed.

An update on the imaging Fourier transform spectrometer for SCUBA-2

We present the recent developments and current design and of an imaging Fourier transform spectrometer (IFTS) for use with SCUBA-2, the second generation, wide-field, submillimetre camera currently under development for the James Clerk Maxwell Telescope (JCMT). The spectrometer will offer variable resolution with resolving powers ranging from R ~10 to 5000. The IFTS uses a folded Mach-Zehnder configuration with novel intensity beam dividers and dual input ports for continuous atmospheric cancellation. This system, which is planned for operation in 2006, will provide simultaneous, broadband, intermediate spectral resolution imaging across both the 850 and 450 μm bands. The optics, observing modes, and projected telescope performance of the IFTS are discussed.

Testing results and current status of FTS-2, an imaging Fourier transform spectrometer for SCUBA-2

The SCUBA-2 imaging Fourier Transform Spectrometer (FTS-2) is a dual-band Mach-Zehnder imaging spectrometer, built for use with the SCUBA-2 camera on the James Clerk Maxwell Telescope (JCMT). FTS-2 will provide resolving powers of R ~ 10 to 5000 across the 450 and 850 μm bands, with a FOV up to 5 arcmin2. The instrument has been built and tested, with first light on the telescope planned for fall 2010. We present the alignment process, laboratory test results, and discuss the first science targets in the context of other similar space and ground-based instruments.

Calibration of the AKARI Far-Infrared Imaging Fourier Transform Spectrometer

The Far-Infrared Surveyor (FIS) onboard the AKARI satellite has a spectroscopic capability provided by a Fourier transform spectrometer (FIS-FTS). FIS-FTS is the first space-borne imaging FTS dedicated to far-infrared astronomical observations. We describe the calibration process of the FIS-FTS and discuss its accuracy and reliability. The calibration is based on the observational data of bright astronomical sources as well as two instrumental sources. We have compared the FIS-FTS spectra with the spectra obtained from the Long Wavelength Spectrometer (LWS) of the Infrared Space Observatory (ISO) having a similar spectral coverage. The present calibration method accurately reproduces the spectra of several solar system objects having a reliable spectral model. Under this condition the relative uncertainty of the calibration of the continuum is estimated to be

Initial results of field testing an infrared water vapor monitor for millimeter astronomy (IRMA III) on Mauna Kea

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Astronomical spectroscopy using an aliased step-and-integrate Fourier transform spectrometer

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SCUBA-2 Fourier transform spectrometer (FTS-2) commissioning results

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Integration and testing of FTS-2 : an imaging Fourier transform spectrometer for SCUBA-2

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