2.7.1 https://spdx.org/licenses/ SPDX CC0-1.0 https://spdx.org/licenses/CC0-1.0.html Creative Commons Zero v1.0 Universal CC0 1.0 Universal is the Creative Commons license applicable to all publicly available SPASE metadata descriptions spase://NASA/DisplayData/POLAR/VIS/PT240S NASA DisplayData Polar Visible Imaging System 24-sec Key Parameters 2025-12-04T13:28:01Z 2021-04-27T15:38:11Z Only known prior ReleaseDate of the metadata 2025-12-04T13:28:01Z Added MetadataRightsList and RightsList(s). Added ResourceType and NamingAuthority. Updated to 2.7.1. Changed http to https in top-level schemaLocation attribute. Fixed version number separator in top-level schemaLocation attribute. ZCB This dataset contains the investigator-selected Key Parameters from the Polar Visible Imaging System (VIS). The VIS key parameter data set is a survey of auroral activity provided by a series of single images showing a significant area of the auroral zone at visible wavelengths. An auroral image of 256 x 256 pixels is produced approximately every 24 seconds dependent on the integration time and filter selected. Some coordinate information is included for viewer orientation. Coordinates are calculated for a grid of 18 x 18 points corresponding to one pixel out of every 15 x 15 pixel block. In addition, a rotation matrix and a table of distortion-correcting look direction unit vectors are provided for the purpose of calculating coordinates for every pixel. To facilitate viewing of the images, a mapping of pixel value to a recommended color table based on the characteristics of the selected filter is included with each image. A relative intensity scale is provided by the uncompressed count table of variable 27. Approximate intensity levels in kiloRayleighs are given in the intensity table of variable 28. The VIS site at http://eiger.physics.uiowa.edu/~vis/software contains information on the availability of more precisely calibrated intensities. The data set also contains various imager-related parameters, plus spacecraft position and velocity vectors, spin axis unit vector, and the sun position unit vector, all in GCI coordinates. Times are given in both the CDF-standard Epoch and the ISTP-standard Time_PB5. spase://SMWG/Person/Louis.A.Frank GeneralContact spase://VSPO/DisplayData/P_POLAR_HDR_VIS_K0 spase://VSPO/DisplayData/POLAR/VIS/PT240S spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb Online Open https://spdx.org/licenses/ SPDX CC0-1.0 https://spdx.org/licenses/CC0-1.0.html Creative Commons Zero v1.0 Universal CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products FTPS from SPDF (not with most browsers) ftps://spdf.gsfc.nasa.gov/pub/data/polar/vis/vis_k0/ HTTPS from SPDF https://spdf.gsfc.nasa.gov/pub/data/polar/vis/vis_k0/ In CDF via HTTP from CDAWeb CDAWeb https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=PO_K0_VIS&index=sp_phys PO_K0_VIS CDF spase://SMWG/Repository/NASA/GSFC/SPDF Online Open https://spdx.org/licenses/ SPDX CC0-1.0 https://spdx.org/licenses/CC0-1.0.html Creative Commons Zero v1.0 Universal CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products CDAWeb HAPI Server https://cdaweb.gsfc.nasa.gov/hapi PO_K0_VIS Web Service to this product using the HAPI interface. CSV CALIBRATED spase://SMWG/Instrument/POLAR/VIS ImageIntensity 1996-11-01T00:00:00 2008-04-28T00:00:00 PT240S Earth.NearSurface.Ionosphere