Search Publications

Mechanical disturbances in Fourier spectrometers

Formisano, Vittorio; Saggin, Bortolino; Comolli, Lorenzo

Fourier spectrometers are sensitive to many kinds of disturbance. This focus is mainly on those connected to mechanical vibrations, assessing the relationships between the mechanical inputs and the deriving effects on the spectra. Mechanical vibrations have two main effects on the spectra, the addition of signals due to direct sensitivity to vibra…

Compact high-resolution spaceborne echelle grating spectrometer with acousto-optical tunable filter based order sorting for the infrared domain from 2.2 to 4.3 µm

Korablev, Oleg; Neefs, Eddy; Berkenbosch, Sophie +12 more

A new compact spaceborne high-resolution spectrometer developed for the European Space Agency's Venus Express spacecraft is described. It operates in the IR wavelength range of 2.2 to 4.3 µm and measures absorption spectra of minor constituents in the Venusian atmosphere. It uses a novel echelle grating with a groove density of 4 lines/mm in…

Mars 1064 nm spectral radiance measurements determined from the receiver noise response of the Mars Orbiter Laser Altimeter

Zuber, Maria T.; Sun, Xiaoli; Neumann, Gregory A. +1 more

A technique was developed to compute the radiance of the scene viewed by the optical receiver of the Mars Orbiter Laser Altimeter. The technique used the detection threshold and the false detection rate of the receiver to provide a passive radiometry measurement of Mars at the 1064 nm wavelength over a 2 nm bandwidth and subkilometer spatial resol…

Quasi-null lens optical system for the fabrication of an oblate convex ellipsoidal mirror: application to the Wide Angle Camera of the Rosetta space mission

Naletto, Giampiero; Ragazzoni, Roberto; da Deppo, Vania +2 more

The design of a quasi-null lens system for the fabrication of an aspheric oblate convex ellipsoidal mirror is presented. The Performance and tolerance of the system have been analyzed. The system has been applied successfully for the fabrication of the primary mirror of the Wide Angle Camera (WAC), the imaging system onboard the Rosetta, the Europ…

Intercalibration of SUMER and CDS on SOHO. III. SUMER and CDS-GIS

Solanki, Sami K.; Schühle, Udo; Pauluhn, Anuschka +2 more

Simultaneous observation of the same solar sources with different instruments is one way to test prelaunch radiometric calibrations and to detect changes in responsivity with time of extreme-ultraviolet instruments in space. Here we present the results of intercalibration of the SUMER (Solar Ultraviolet Measurements of Emitted Radiation) spectrome…

Intercalibration of SUMER and CDS on SOHO. II. SUMER Detectors A and B and CDS NIS: Erratum

Solanki, Sami K.; Wilhelm, Klaus; Schühle, Udo +6 more

Intercalibration of SUMER and CDS on SOHO. II. SUMER detectors A and B and CDS NIS

Solanki, Sami K.; Wilhelm, Klaus; Schühle, Udo +5 more

Results of an intercalibration between the extreme-ultraviolet spectrometers Coronal Diagnostic Spectrometer (CDS) and Solar Ultraviolet Measurements of Emitted Radiation (SUMER) on board the Solar and Heliospheric Observatory (SOHO) are reported. The results of the joint observing program Intercal_01 are described, and intercalibration results up…

Private life of an integrating sphere: the radiant homogeneity of the Descent Imager -Spectral Radiometer calibration sphere

Rizk, Bashar

Perturbations to an integrating sphere's radiant uniformity by a protruding optical system are mapped. A sphere provides the Descent Imager-Spectral Radiometer sensor head (DISR SH), a practical platform for many of its subsystems' calibrations, but the resulting nonuniformity threatens the goal of accurate radiometry. An apparatus with a nearly i…

Radiometric Calibration of the Vacuum-Ultraviolet Spectrograph SUMER on the SOHO Spacecraft with the B Detector

Wilhelm, Klaus; Schühle, Udo; Curdt, Werner +3 more

The Solar Ultraviolet Measurement of Emitted Radiation (SUMER) vacuum-ultraviolet spectrograph was calibrated in the laboratory before the integration of the instrument on the Solar and Heliospheric Observatory (SOHO) spacecraft in 1995. During the scientific operation of the SOHO it has been possible to track the radiometric calibration of the SU…

Experimental Study of External Occulters for the Large Angle and Spectrometric Coronagraph 2: LASCO-C2

Lamy, Philippe; Bout, Maurice; Maucherat, André +2 more