Speaker
Dr
Heikki Saari
(VTT Microspectrometers)
Description
ALTIUS UV channel is intended for spectral imaging measurements in the wavelength range 250 – 400 nm at FWHM resolution around 2.5 nm. The UV channel entrance pupil diameter is 12.3 mm for bright limb channel and 50 mm for stellar occultation channel. The image size of the UV detector is 4.25 mm x 4.25 mm. The UV FPI assembly based tunable filter is placed in the optical chain in a collimated beam with the field stop placed between the 2nd and 3rd FPI module.
The optics design is based on 14 mm clear aperture of each of the four FPI modules. In this presentation we will describe the space heritage of VTT piezo-actuated FPI technology from the Finnish Aalto-1 Cubesat spectral imager (AaSI) built in the ESA “Contract No. 4000106267/12/NL/CP – MEMS Fabry-Perot Interferometer Technology for Miniaturized Hyperspectral Imagers and Microspectrometers” and from the PICASSO VISION instrument built in the ESA GSTP project RFQ/3-14170/14/NL/MH – “CUBESAT Technology Pre-Developments, QB-50: PICASSO Mission & VISION Miniaturized Hyperspectral Imager”. We will also present preliminary results from nationally funded HyperGlobal project on ship SO2 emission measurements based on UV FPI hyperspectral imager for the wavelength range 300 – 325 nm. The second part of the presentation describes the present status of the ALTIUS UV FPI assembly design based on Hafnium Oxide – Silicon Dioxide Bragg mirrors. VTT has developed in its internal development project cascaded UV FPI assembly laboratory prototype based on FPIs designed for 300 – 360 nm and 345 - 395 nm spectral ranges. Preliminary characterization results of this assembly will be shown.
Primary author
Dr
Heikki Saari
(VTT Microspectrometers)
Co-authors
Mr
Antti Näsilä
(VTT Microspectrometers)
Mr
Christer Holmlund
(VTT Microspectrometers)
Dr
Harri Ojanen
(VTT Microspectrometers)
