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Global Ultraviolet Imager (GUVI) Data from the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED) Mission
Entry ID: TIMED_GUVI


Summary
Abstract: The Global Ultraviolet Imager (GUVI) is one of four instruments that constitute the TIMED spacecraft, the first mission of the NASA Solar Connections program.

Data from the GUVI instrument is procesed on the ground to generate data products at the different levels.

Level 1A is a "virtual" data product file in the sense that the data is not directly outputted to a data file. It consists of raw sensor data at full resolution. Level 1B is also a "virtual" data product file and it contains uncompressed instrument data, using a simple constrained maximum error compression algorithm that achieves modest compression factors, and has been calibrated to convert to unts of radiance within the specified "color" of the GUVI data (Rayleighs/color).

The Level 1C data products contain data directly measured by the sensors, such as photometer counts, uncertainties, light intensities and pointing information derived from the GUVI raw sensor data and the TIMED Satellite ephemeris data. The data are gridded into a GUVI based coordinate system consisting of the along orbit position of the sensor and the angle of the scan from the nadir position. This gridding eliminates overlap from scan to scan due to the large instantaneous field-of-view of GUVI (about 12 degrees) and involves coaddition to place the values on a uniform instrument shared grid. The data is then determined whether its from day, night, aurora or twilight pixels.

The Level 2B data products contain environmental parameters which are derived from the sensor data by scientific algorithms specific to day, night, and auroral regions. The data is averaged into 100 x 100 km2 resolution to form "super pixels" on the day and night and 25 x 25 km2 for the auroral products. The "super pixels" are then processed by the algorithms to yield geophysical parameters which are calculated from the radiance of the different colors.

The GUVI data product files are stored in full orbit increments according to the date and revolution number and data product level type. These files are in NetCDF which is a self describing platform independent binary format.

See http://guvi.jhuapl.edu/data/understanding.shtml

Related URL
Link: View Related Information
Description: Access to GUVI TIMED data at JHU/APL


Link: View Related Information
Description: TIMED Science Data System (registration required)


Geographic Coverage
 N: 90.0 S: -90.0  E: 180.0  W: -180.0

Data Set Citation
Dataset Originator/Creator: GUVI Science Team
Dataset Title: Global Ultraviolet Imager (GUVI) Data from TIMED
Dataset Release Date: 2002
Dataset Release Place: Laurel, MD
Dataset Publisher: Johns Hopkins University/Applied Physics Laboratory
Online Resource: http://guvitimed.jhuapl.edu/


Temporal Coverage
Start Date: 2002-02-17


Location Keywords
GEOGRAPHIC REGION > GLOBAL
VERTICAL LOCATION > IONOSPHERE
VERTICAL LOCATION > MESOSPHERE
VERTICAL LOCATION > THERMOSPHERE


Science Keywords
ATMOSPHERE >ATMOSPHERIC TEMPERATURE >UPPER AIR TEMPERATURE    [Definition]
SPECTRAL/ENGINEERING >ULTRAVIOLET WAVELENGTHS >SENSOR COUNTS    [Definition]
SPECTRAL/ENGINEERING >ULTRAVIOLET WAVELENGTHS >ULTRAVIOLET FLUX    [Definition]
SPECTRAL/ENGINEERING >ULTRAVIOLET WAVELENGTHS >ULTRAVIOLET RADIANCE    [Definition]
SUN-EARTH INTERACTIONS >IONOSPHERE/MAGNETOSPHERE DYNAMICS >AURORAE    [Definition]
SUN-EARTH INTERACTIONS >SOLAR ENERGETIC PARTICLE FLUX >ELECTRON FLUX    [Definition]
SUN-EARTH INTERACTIONS >SOLAR ENERGETIC PARTICLE FLUX >PROTON FLUX    [Definition]
SUN-EARTH INTERACTIONS >SOLAR ACTIVITY >SOLAR ULTRAVIOLET EMISSIONS    [Definition]
ATMOSPHERE >ATMOSPHERIC CHEMISTRY >NITROGEN COMPOUNDS >MOLECULAR NITROGEN    [Definition]
ATMOSPHERE >ATMOSPHERIC CHEMISTRY >OXYGEN COMPOUNDS >MOLECULAR OXYGEN    [Definition]


ISO Topic Category
null
null
null


Platform
TIMED >Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics    [Information]


Instrument
GUVI >Global Ultraviolet Imager    [Information]


Project
TIMED >Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics    [Information]
STP >NASA Solar Terrestrial Probes Program    [Information]


Keywords
Solar EUV Flux Index
Q(env)
effective energy flux
effective average energy
height of peak ionization rate
neutral density profiles
GUVI
boundary specification


Data Set Progress
IN WORK


Originating Center
JHU/APL


Data Center
Global Ultraviolet Imager Team, Applied Physics Laboratory, Johns Hopkins University    [Information]
Data Center URL: http://guvi.jhuapl.edu/home.html

Data Center Personnel
Name: ROBIN BARNES
Phone: 240-228-8134
Email: Robin.Barnes at jhuapl.edu
Contact Address:
Applied Physics Laboratory
Johns Hopkins University
11100 Johns Hopkins Road
City: Laurel
Province or State: MD
Postal Code: 20723-6099
Country: USA


TIMED Science Data System, Applied Physics Laboratory, Johns Hopkins University    [Information]
Data Center URL: http://www.timed.jhuapl.edu/WWW/scripts/mdc_home.pl

Data Center Personnel
Name: STUART NYLAND
Contact Address:
Applied Physics Laboratory
Johns Hopkins University
11100 Johns Hopkins Road
City: Laurel
Province or State: MD
Postal Code: 20723-6099
Country: USA



Distribution
Distribution_Media: online www, ftp
Distribution_Format: netCDF
Fees: none


Personnel
ANDREW B. CHRISTENSEN
Role: INVESTIGATOR
Phone: 310-336-7084
Email: andy.christensen at aero.org
Contact Address:
The Aerospace Corporation
2350 E. El Segundo Blvd.
City: El Segundo
Province or State: CA
Postal Code: 90245-4691
Country: USA


Publications/References
Online publications and a list of references is avilable from:
http://guvi.jhuapl.edu/science/publication.shtml

Creation and Review Dates
DIF Creation Date: 2003-10-13
Last DIF Revision Date: 2016-06-03



Link to Web Site