Radar Space Sciences Laboratory
Public Access Geospace Instruments
CCD Imaging Systems - Microbarograph Array - Magnetometer - HF Receive Array*
Arecibo Observatory, Puerto Rico
System Information
The
All-sky Imager is a sensitive instrument designed to detect faint
terrestrial emissions called 'airglow'. The airglow emissions occur due
to photochemical reaction of atoms and molecules in the upper atmosphere
in the altitude region of 70 to 300 km. These emissions ranging from
near infrared to ultraviolet, originate from different altitude region.
For example, 5577, 6300, and 7774 nm emission originate from heights of
around 96, 200-300, and 250-350 km. Tropospheric sources power
atmospheric waves propagating upwards and result in visible disturbances
in the airglow emission intensity. These faint emissions can be
captured using imager during moonless and clear sky condition.
The
all-sky images produced also give a large scale two dimensional
(spatial) versus time context to F-region measurements made by the
powerful Incoherent Scatter Radar operating next to the imager at the
Arecibo Observatory.
The
total spectral range is 190-1080 nm but as the maximum quantum
efficiency of the CCD (70%) peaks at 550 nm. Thus, operating outside
this range would significantly affect the signal-to-noise ratio.
The
system is set up to function without human intervention during normal
operation. Image data is captured by the imager using the CDAS software
[Makela and Nicolls, 2003] at AO during moonless periods. It is stored
locally and then sent to the Penn State RSSL server in the morning after
for processing, archiving, and publication. Quick look image data is
also sent to the server in near real time. All the data as well as the
quick look images are available on this website.
Hardware Setup
Camera: Finger Lakes Instrumentation
Front primary lens: Mamiya 24mm/F4.0 with 180 FOV
Telecentric optics in front of filterwheel: 76.2/75 mm lenses
CCD re-imaging optics: Two achromats with diameters 76.2 mm and 72 mm and a Canon camera lens (85mm/F1.2).
