Visible/Infrared Instruments
type: Concept

VIS
type: Concept
in scheme: instruments
definition: The Visible Imaging System (VIS) is a set of three low-light-level cameras flown on the POLAR spacecraft of the International Solar-Terrestrial Physics (ISTP) program. Two of these cameras share primary and some secondary optics and are designed to provide images of the nighttime auroral oval at altitudes ~1 to 8 RE (Earth radius) as viewed from the eccentric, polar orbit of the spacecraft. A third camera is used to monitor the directions of the fields-of-view of the auroral cameras with respect to the sunlit Earth. The auroral images are to be gained with filters with narrow passbands at visible wavelengths. The emissions of interest include those from N2+ at 391.4 nm, Ol at 557.7 and 630.0 nm, Hl at 656.3 nm and OII at 732.0 nm. The primary scientific objectives of this imaging instrumentation, together with the in situ measurements from instruments on board the ensemble of ISTP spacecraft, are (1) quantitative assessment of the dissipation of magnetospheric energy into the auroral ionosphere, (2) an instantaneous reference system for the above in situ observations, (3) development of a substantial model of the energy flow within the magnetosphere, (4) investigation of the topology of the magnetosphere, and (5) delineation of the responses of the magnetosphere to substorms and variable solar wind conditions. For more information, see: http://www-pi.physics.uiowa.edu/www/vis/ and http://pwg.gsfc.nasa.gov/polar/polar_inst.shtml Group: Instrument_Details Entry_ID: VIS Group: Instrument_Identification Instrument_Category: Solar/Space Observing Instruments Instrument_Class: Visible/Infrared Instruments Short_Name: VIS Long_Name: Visible Imaging System (Polar) End_Group Group: Associated_Platforms Short_Name: POLAR End_Group Online_Resource: http://www-pi.physics.uiowa.edu/www/vis/description.html Online_Resource: http://www-pi.physics.uiowa.edu/vis/vis_description/vis_description.htmlx Sample_Image: http://www-pi.physics.uiowa.edu/www/vis/vis_description/plate_1a.gif G…