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Polar Ultraviolet Imager, Key Parameters

ResourceID
spase://VSPO/NumericalData/POLAR/UVI/K0_CDF

Description

The Ultraviolet Imager (UVI) is a small camera that detected and produced images of the ultraviolet light of the aurora, day and night.
Key Parameter (KP) images are calculated at nominal 5-10 minute intervals at spacecraft altitudes above 6 Re. The UVI KP image is
background subtracted and calibrated to radiance values (photon cm^-2 cm^-1). The data is a rectangular two-dimensional array
(228 rows x 200 columns). Only a circular region of the rectangular array contains valid image data. The UVI KP Image Archive
(http://tideuvira.nsstc.nasa.gov/uvi/kpgs-Data.htm) allows the user to look at all the KP Mosaics for a selected month. The gif or png
plot files contain the up to 35 KP images taken with the LBHL filter. Reference images are also provided showing the location of the
UVI field of view relative to continental outlines.

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Details

Version:2.2.9

NumericalData

ResourceID
spase://VSPO/NumericalData/POLAR/UVI/K0_CDF
ResourceHeader
ResourceName
Polar Ultraviolet Imager, Key Parameters
ReleaseDate
2019-08-05 15:03:35Z
Description

The Ultraviolet Imager (UVI) is a small camera that detected and produced images of the ultraviolet light of the aurora, day and night.
Key Parameter (KP) images are calculated at nominal 5-10 minute intervals at spacecraft altitudes above 6 Re. The UVI KP image is
background subtracted and calibrated to radiance values (photon cm^-2 cm^-1). The data is a rectangular two-dimensional array
(228 rows x 200 columns). Only a circular region of the rectangular array contains valid image data. The UVI KP Image Archive
(http://tideuvira.nsstc.nasa.gov/uvi/kpgs-Data.htm) allows the user to look at all the KP Mosaics for a selected month. The gif or png
plot files contain the up to 35 KP images taken with the LBHL filter. Reference images are also provided showing the location of the
UVI field of view relative to continental outlines.

Contacts
RolePerson
1.PrincipalInvestigatorspase://SMWG/Person/George.K.Parks
2.MetadataContactspase://SMWG/Person/Peggy.Sloan
PriorIDs
spase://VMO/NumericalData/POLAR/UVI/K0_CDF
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb
Availability
Online
AccessRights
Open
AccessURL
Name
FTP access to files at SPDF
URL
ftps://spdf.gsfc.nasa.gov/pub/data/polar/uvi/uvi_k0/
AccessURL
Name
HTTP access to files at SPDF
URL
https://spdf.gsfc.nasa.gov/pub/data/polar/uvi/uvi_k0/
Description

In CDF via HTTP from SPDF

AccessURL
Name
CDAWeb
URL
https://cdaweb.sci.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=PO_K0_UVI&index=sp_phys
ProductKey
PO_K0_UVI
Format
CDF
ProcessingLevel
Calibrated
ProviderProcessingLevel
Level 1
InstrumentIDs
spase://SMWG/Instrument/POLAR/UVI
MeasurementType
ImageIntensity
TemporalDescription
TimeSpan
StartDate
1996-03-23 15:56:15
StopDate
2008-02-10 18:40:28
SpectralRange
Ultraviolet
ObservedRegion
Earth.NearSurface.Ionosphere
Caveats
UVI Key Parameters are summary data only. In some cases parameters such as pointing and calibration were not be adequate to support quantitative scientific analysis. They should not to be used for presentation, publication, or analysis. The UVI KP CDF files only contain output for normal instrument mode when the spacecraft is in 9.2 second science telemetry mode. No Key Parameters are produced when the spacecraft is in maneuver telemetry mode, when UVI is in star (fast) mode, and when the despun platform is pointed away from the earth.
Parameter #1
Name
FUV Image
ParameterKey
IMAGE_DATA
Description

Far Ultraviolet Image - 8 degree full width (228 x 200 pixels)

Caveats
The UVI field of view is circular with an 8 degree full width. The circular image is stored in IMAGE_DATA as a rectangular array of 228 rows and 200 columns. Consequently, the corners of each image contain non-image data. The non-active corner pixel locations are identified by a corner fill value = -128. The image is oriented such that the direction of decreasing row number points along the spacecraft spin axis. The direction of decreasing column number points to the outboard direction (relative to the spin axis). The orientation is the same for both detectors.
Units
photon cm^-2 s^-1
Structure
Size
228 200
Wave
WaveType
Photon
Qualifier
Integral
WaveQuantity
Intensity
WavelengthRange
SpectralRange
Ultraviolet
Low
125
High
190
Units
nanometers
Bin
BandName
1304 filter
Low
125
High
135
Bin
BandName
1356 filter
Low
128
High
142
Bin
BandName
LBHS filter
Low
135
High
160
Bin
BandName
LBHL filter
Low
160
High
190
Bin
BandName
SOLR filter
Low
175
High
190
Parameter #2
Name
Time Line
ParameterKey
Epoch
Description

Image time.

Caveats
The time in EPOCH and Time_PB5 refer to the center of the image in IMAGE_DATA. There is an offset of up to 8 major frames between the beginning of the image exposure and the ATC telemetry time stamp. The times shown here are corrected for this and describe the actual time of exposure.
Units
ms
ValidMin
01-Jan-1990 00:00:00.000
ValidMax
31-Dec-2020 23:59:59.000
FillValue
-1.0E31
Support
SupportQuantity
Temporal
Parameter #3
Name
Time Line
ParameterKey
Time_PB5
Description

Image time.

Caveats
The time in EPOCH and Time_PB5 refer to the center of the image in IMAGE_DATA. There is an offset of up to 8 major frames between the beginning of the image exposure and the ATC telemetry time stamp. The times shown here are corrected for this and describe the actual time of exposure.
Structure
Size
3
Element
Name
Year
Index
1
Units
year
ValidMin
1990
ValidMax
2020
FillValue
-2147483648
Element
Name
Day of Year (Jan 1 = Day 1)
Index
2
Units
day
ValidMin
1
ValidMax
366
FillValue
-2147483648
Element
Name
Elapsed millisecond of day
Index
3
Units
msec
ValidMin
0
ValidMax
86399000
FillValue
-2147483648
Support
SupportQuantity
Temporal
Parameter #4
Name
Relative beginning of image
ParameterKey
IMG_MINUS_MSEC
Description

The start of the image, measured from EPOCH/Time_PB5.

Caveats
The beginning and ending time of the image is specified in msec relative to the time in EPOCH and Time_PB5 by IMG_MINUS_MSEC and IMG_PLUS_MSEC, respectively.
Units
ms
ValidMin
-1800000.0
ValidMax
0.0
FillValue
-1.0E31
Support
SupportQuantity
Temporal
Parameter #5
Name
Relative end of image
ParameterKey
IMG_PLUS_MSEC
Description

The end of the image, measured from EPOCH/Time_PB5.

Caveats
The beginning and ending time of the image is specified in msec relative to the time in EPOCH and Time_PB5 by IMG_MINUS_MSEC and IMG_PLUS_MSEC, respectively.
Units
ms
ValidMin
0.0
ValidMax
1800000.0
FillValue
-1.0E31
Support
SupportQuantity
Temporal
Parameter #6
Name
Post Gap Flag
ParameterKey
POST_GAP_FLAG
Description

Explanation of preceding gap.

Caveats
A gap is defined if the time between records is greater than twice the nominal output time (NOMINAL_OUTPUT_PERIOD). The following values are defined for POST_GAP_FLAG: O = No Gap; 1 = Wrong Mode; 2 = Missing Data; 3 = Noisy Data; 4-9 = undefined; 10 = High voltage not enabled; 11 = gain set to zero; 12 =The first minor frame containing UVI housekeeping was zero filled 13 = Unable to sync with telemetry stream; 14 = No background images were present; 15 = Requested filter setting was not present; 16 = Spacecraft was near perigee pass where no kp's are generated; 17 = Despun platform was pointing away from the earth; 18 = Image data lay outside requested process window (Not used for production); 19 = Unknown. Note that long gaps may be caused by multiple events. POST_GAP_FLAG attempts to represent the most severe event contributing to the gap. Also, since each image frame requires a minimum of 4 major frames (36.8 s) very short values of NOMINAL_OUTPUT_PERIOD on the order of 1 minute may always encounter a gap since the desired images may be several minutes apart. This condition is not trapped and will result in an unknown value for the post gap flag.
ValidMin
0
ValidMax
19
FillValue
-2147483648
Support
SupportQuantity
Other
Parameter #7
Name
Quality Flag
ParameterKey
QUALITY_FLAG
Description

Bit-mapped quality indicator.

Caveats
QUALITY_FLAG is a bit-mapped flag in which each bit corresponds to a single quality condition. The most significant bit (minus sign) is not used. Consequently up to 31 different quality conditions can be simultaneously flagged. The flags are ordered in severity with increasing bit position. The following _hexadecimal_ values have been defined for QUALITY_FLAG: 0 = No errors or quality conditions; 1 = an error occurred writing an SFDU comment; 2 = image time was outside of selected processing window; 4 = some level zero minor frames had fill values; 8 = some level zero minor frames had sync errors; 10 = the image single frame integration period could not be determined due to bad telemetry (assumed to be 4 major frames); 20 = the despun platform was in motion or had not settled down from a motion; 40 = the pointing calculations have not been validated or may be unreliable; 80 = the time flags for this image may be unreliable; 100 = there was an error decode star mode data; 200 =some major frames were missing but an image could be partially reconstructed; 400 = calibration data is missing or otherwise invalid; 800 = a background image could not be found; 1000 = the requested output image could not be found.
ValidMin
0
ValidMax
2147483647
FillValue
-2147483648
Support
SupportQuantity
Other
Parameter #8
Name
Nominal Time Between Records
ParameterKey
NOMINAL_OUTPUT_PERIOD
Description

Nominal time between output records.

Caveats
This is the nominal time between output records. The actual output spacing will vary depending on the nature of the observing sequences being run.
Units
minutes
ValidMin
0
ValidMax
300
FillValue
-2147483648
Support
SupportQuantity
Other
Parameter #9
Name
Primary/secondary detectors
ParameterKey
SYSTEM
Description

Operating system.

Caveats
UVI has two independent systems. PRIMARY: +1, SECONDARY: -1
ValidMin
-1
ValidMax
1
FillValue
-2147483648
Support
SupportQuantity
Other
Parameter #10
Name
Observing sequence
ParameterKey
SEQ
Description

Predefined sequence of observations. Definitions will change over mission.

ValidMin
0
ValidMax
49
FillValue
-2147483648
Support
SupportQuantity
Other
Parameter #11
Name
Observing mode
ParameterKey
MODE
Description

Instrument operating mode.

Caveats
(1=Normal, 2=Star, 3=Idle) Normal mode produces one 200 x 228 image every 4 major frames. Star mode produces multiple miniframe images every major frame. Idle mode produces no image output.
ValidMin
1
ValidMax
3
FillValue
-2147483648
Support
SupportQuantity
Other
Parameter #12
Name
Detector Gain Setting
ParameterKey
GAIN
Description

Detector gain setting

Caveats
0=off, 16=highest sensitivity
ValidMin
0
ValidMax
16
FillValue
-2147483648
Support
SupportQuantity
Other
Parameter #13
Name
Aperture door position
ParameterKey
DOOR
Description

Aperture door position

Caveats
(OPEN: +1, CLOSED: -1) MgF2 window in door allows viewing when closed.
ValidMin
-1
ValidMax
1
FillValue
-2147483648
Support
SupportQuantity
Other
Parameter #14
Name
GCI Spacecraft Position Vector
ParameterKey
GCI_POSITION
Description

Spacecraft Position in GCI, 3 comp.

Caveats
Copied from S/C orbit file.
Units
km
Structure
Size
3
Element
Name
X (GCI)
Index
1
ValidMin
-60000.0
ValidMax
60000.0
FillValue
-1.0E31
Element
Name
Y (GCI)
Index
2
ValidMin
-60000.0
ValidMax
60000.0
FillValue
-1.0E31
Element
Name
Z (GCI)
Index
3
ValidMin
-60000.0
ValidMax
60000.0
FillValue
-1.0E31
Support
SupportQuantity
Other
Parameter #15
Name
GCI Spacecraft Attitude Vector
ParameterKey
ATTITUDE
Description

Spacecraft Attitude in GCI, 3 comp.

Caveats
Calculated from S/C attitude file.
Structure
Size
3
Element
Name
X (GCI)
Index
1
ValidMin
-1.0
ValidMax
1.0
FillValue
-1.0E31
Element
Name
Y (GCI)
Index
2
ValidMin
-1.0
ValidMax
1.0
FillValue
-1.0E31
Element
Name
Z (GCI)
Index
3
ValidMin
-1.0
ValidMax
1.0
FillValue
-1.0E31
Support
SupportQuantity
Other
Parameter #16
Name
GCI Sun Vector
ParameterKey
GCI_SUN
Description

Sun Position in GCI, 3 comp.

Caveats
Vector pointing to sun.
Units
km
Structure
Size
3
Element
Name
X (GCI)
Index
1
ValidMin
-1.6E8
ValidMax
1.6E8
FillValue
-1.0E31
Element
Name
Y (GCI)
Index
2
ValidMin
-1.6E8
ValidMax
1.6E8
FillValue
-1.0E31
Element
Name
Z (GCI)
Index
3
ValidMin
-1.6E8
ValidMax
1.6E8
FillValue
-1.0E31
Support
SupportQuantity
Other
Parameter #17
Name
GCI Look Direction
ParameterKey
GCI_LOOK_DIR
Description

Unit vector along field of view.

Caveats
GCI_LOOK_DIR is a unit vector in GCI coordinates pointing from the spacecraft along the center of the UVI line of sight. An external utility can be used to calculate latitude and longitude for any pixel of the UVI image.The pointing utility can be found on the UVI WWW home page
Structure
Size
3
Element
Name
X (GCI)
Index
1
ValidMin
-1.0
ValidMax
1.0
FillValue
-1.0E31
Element
Name
Y (GCI)
Index
2
ValidMin
-1.0
ValidMax
1.0
FillValue
-1.0E31
Element
Name
Z (GCI)
Index
3
ValidMin
-1.0
ValidMax
1.0
FillValue
-1.0E31
Support
SupportQuantity
Other
Parameter #18
Name
DSP Nadir Offset Angle
ParameterKey
DSP_ANGLE
Description

Offset angle of despun platform from nadir.

Caveats
Positive in direction opposite of spacecraft rotation.
Units
Degree
ValidMin
-180.0
ValidMax
180.0
FillValue
-1.0E31
Support
SupportQuantity
Other
Parameter #19
Name
Image Type
ParameterKey
FILTER
Description

Filter selection.

Caveats
1304=2, 1356=3, LBHS=4, LBHL=5, SOLR=6
ValidMin
2
ValidMax
6
FillValue
-2147483648
Support
SupportQuantity
Other
Parameter #20
Name
Geodetic Latitude
ParameterKey
GEODETIC_LAT
Description

Geodetic latitude for IMAGE_DATA (23 x 20 pixels)

Caveats
Sparse matrices (every 10 pixels) of latitude and longitude are given in GEODETIC_LAT and GEODETIC_LONG, respectively. Latitude & longitude are given in geodetic coordinates (determined from the normal to the assumed surface of the earth [assumed to be an ellipsoid of revolution]) and not in geocentric coordinates (determined relative to the center of the earth).
Units
Degrees
Structure
Size
23 20
Support
SupportQuantity
Other
Parameter #21
Name
Geodetic Longitude
ParameterKey
GEODETIC_LONG
Description

Geodetic longitude for IMAGE_DATA (23 x 20 pixels)

Caveats
Sparse matrices (every 10 pixels) of latitude and longitude are given in GEODETIC_LAT and GEODETIC_LONG, respectively. Latitude & longitude are given in geodetic coordinates (determined from the normal to the assumed surface of the earth [assumed to be an ellipsoid of revolution]) and not in geocentric coordinates (determined relative to the center of the earth).
Units
Degrees
Structure
Size
23 20
Support
SupportQuantity
Other
Parameter #22
Name
Row Number
ParameterKey
ptr_row
Description

Row Number

Units
pixel
Structure
Size
23
ValidMin
1.0
ValidMax
228.0
FillValue
-1.0E31
Support
SupportQuantity
Other
Parameter #23
Name
Column Number
ParameterKey
ptr_col
Description

Column Number

Units
pixel
Structure
Size
20
ValidMin
1.0
ValidMax
200.0
FillValue
-1.0E31
Support
SupportQuantity
Other
Parameter #24
Name
Row Number
ParameterKey
row
Description

Row Number

Units
pixel
Structure
Size
228
ValidMin
1.0
ValidMax
228.0
FillValue
-1.0E31
Support
SupportQuantity
Other
Parameter #25
Name
Column Number
ParameterKey
ptr_col
Description

Column Number

Units
pixel
Structure
Size
20
ValidMin
1.0
ValidMax
200.0
FillValue
-1.0E31
Support
SupportQuantity
Other