Airglow Instruments


MLTP is a simple multi-wavelength airglow photometer which has F/2 optics and full field of view ~4o. It measures mesospheric OH (at 840 and 846 nm rotational lines from ~85 km) and O2 (at 866 and 868 nm rotational lines from ~94 km) emissions together with thermospheric O(1D) (~220 km, 630 nm) emission intensities with the help of seven temperature controlled interference filters having FWHM ~0.45 nm. The temperatures are derived at OH and O2 emissions using the ratio and slope methods respectively. The MLTP uses H7421-50 photon counting module as detector. The filter rotations are synchronized with the counting unit C8855-01 of photomultiplier tube for the operations. The data is saved on a computer hard disk in ascii format for further analysis. Usally it is being operated on all the clearly sky nights. Airglow Imager The Airglow Imager which provide real time information on the spatial scales and direction of propagation of the dynamical variability at mesospheric altitudes (OH and O(1S) emissions) and thermosphere-ionosphere system (O(1D) emission) is being installed at NARL. The imager uses a circular medium format F/4Mamiya fish eye lens with a focal length of 24mm. It measures OH, O(1S) and O(1D) emissions at peak wavelengths 840, 558 and 630 nm respectively. The detector is a back illuminated e2v CCD47-10 chip (Acton Pixis 1024B) CCD with 1024x1024 square pixels of 13.3 μm size having 100% fill factor and 16 bit depth. The movement of filter wheel is controlled by a menu driven software synchronized with the CCD detector. The CCD is thermoelectrically cooled to -70oC to ensure the low dark noise before the operation. In the present set-up, we bin the images for 2x2 pixels making an effective 512x512 super pixels image on the chip to enhance the signal-to-noise ratio. Though imager has full field of view ~170o, at present we have limited this to 90o. The final image captured by the imager is stored on the computer hard disk for further analysis.

Airglow Imager The Airglow Imager which provide real time information on the spatial scales and direction of propagation of the dynamical variability at mesospheric altitudes (OH and O(1S) emissions) and thermosphere-ionosphere system (O(1D) emission) is being installed at NARL. The imager uses a circular medium format F/4Mamiya fish eye lens with a focal length of 24mm. It measures OH, O(1S) and O(1D) emissions at peak wavelengths 840, 558 and 630 nm respectively. The detector is a back illuminated e2v CCD47-10 chip (Acton Pixis 1024B) CCD with 1024x1024 square pixels of 13.3 μm size having 100% fill factor and 16 bit depth. The movement of filter wheel is controlled by a menu driven software synchronized with the CCD detector. The CCD is thermoelectrically cooled to -70oC to ensure the low dark noise before the operation. In the present set-up, we bin the images for 2x2 pixels making an effective 512x512 super pixels image on the chip to enhance the signal-to-noise ratio. Though imager has full field of view ~170o, at present we have limited this to 90o. The final image captured by the imager is stored on the computer hard disk for further analysis.