Version:2.2.2
NumericalData
ResourceID
spase://NASA/NumericalData/TIMED/GUVI/Imaging/L1B_Limb
ResourceHeader
ResourceName
TIMED GUVI Imaging Level 1B Limb
ReleaseDate
2020-07-07 21:15:37Z
Description
Level 1B Limb data contains calibrated radiance data over multiple scans that are geolocated into a GUVI-based coordinate system on the limb.
Acknowledgement
NASA, Andrew B. Christensen
Contacts
InformationURL
Name
Imaging L1B Data Information
URL
PriorIDs
spase://VITMO/NumericalData/TIMED/GUVI/Imaging/L1B_Limb
spase://VSPO/NumericalData/TIMED/GUVI/Imaging/L1B_Limb
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
GUVI POC L1B Imaging Data Request
URL
Description
This web page allows the request of data files for this product. To request data: select the year and day then press display.
Format
NetCDF
Encoding
GZIP
Acknowledgement
NASA, Andrew B. Christensen
ProcessingLevel
Calibrated
ProviderResourceName
GUVI Imaging L1B Limb data
ProviderProcessingLevel
Level 1B
ProviderVersion
009
InstrumentIDs
MeasurementType
Radiance
TemporalDescription
TimeSpan
StartDate
2002-01-08 00:00:00.000
StopDate
2007-12-11 00:05:38.000
ObservedRegion
Earth.NearSurface.Thermosphere
ObservedRegion
Earth.NearSurface.Ionosphere
ObservedRegion
Earth.NearSurface.AuroralRegion
Keywords
TIMED
GUVI
Imaging
Limb
lower thermosphere
ionosphere
MLTI
Parameter #1
Name
Starting Time
ParameterKey
Starting_Time
Description
Starting date/time of file's observation encoded in a 13-digit string and stored as a single netCDF global attribute.
Units
yyyydoyhhmmss
Structure
Size
1
Description
Dimensions: [1] - this parameter is a single element per file.
Support
Parameter #2
Name
Stopping Time
ParameterKey
Stopping_Time
Description
Stopping date/time of file's observation encoded in a 13-digit string and stored as a single netCDF global attribute.
Units
yyyydoyhhmmss
Structure
Size
1
Description
Dimensions: [1] - this parameter is a single element per file.
Support
Parameter #3
Name
Day of Year
ParameterKey
DOY
Description
Date of observation in number of days since start of current year.
Units
days
Structure
Size
0
Description
Dimensions: [n] - where n is the number of scans, or NumScans, (i.e., records) in an orbital file.
ValidMin
1
ValidMax
366
Support
Parameter #4
Name
Time
ParameterKey
Time
Description
Time of observation in integral number of milliseconds since start of current day. Timestamp marks beginning of interval
Units
ms
UnitsConversion
1e-3>s
Structure
Size
0
Description
Dimensions: [n] - where n is the number of scans, or NumScans, (i.e., records) in an orbital file.
ValidMin
0
ValidMax
86399999
Support
Parameter #5
Name
Detector
ParameterKey
Detector
Description
Detector number of detector being used
Units
unitless
Structure
Size
0
Description
Dimensions: [n] - where n is the number of scans, or NumScans, (i.e., records) in an orbital file.
ValidMin
1
ValidMax
2
Support
Parameter #6
Name
Slit position
ParameterKey
Slit
Description
Slit position being used where 0 = closed, 1 = wide, 2 = medium, 3 = narrow, and 4 = unknown.
Units
unitless
Structure
Size
0
Description
Dimensions: [n] - where n is the number of scans, or NumScans, (i.e., records) in an orbital file.
ValidMin
0
ValidMax
4
Support
SupportQuantity
InstrumentMode
Parameter #7
Name
Mirror start position
ParameterKey
MirrorStartPosition
Description
Starting position of the mirror.
Units
unitless
Structure
Size
0
Description
Dimensions: [n] - where n is the number of scans, or NumScans, (i.e., records) in an orbital file.
ValidMin
49
ValidMax
53
Support
Parameter #8
Name
Mirror nadir position
ParameterKey
MirrorNadirPosition
Description
Position of the mirror when at nadir.
Units
unitless
Structure
Size
0
Description
Dimensions: [n] - where n is the number of scans, or NumScans, (i.e., records) in an orbital file.
ValidMin
249
ValidMax
253
Support
Parameter #9
Name
Dark count pixels
ParameterKey
DarkCountPixels
Description
Four separate dark pixels that measure instumental dark counts. These values are use to scale a dark pixel mask to obtain an estimated dark level that can then subtracted from each pixel.
Caveats
This correction is generally not applied because the GUVI dark pixels seem to see varying amounts of scattered light at a level substantially larger than the miniscule "true" dark level.
Units
counts
Structure
Size
4
Description
Dimensions: [4,n] - where 4 is the number of dark count pixels, or NumDarkCountPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
Support
Parameter #10
Name
Background count pixels
ParameterKey
BackgroundPixels
Description
GUVI long backgrounds measured on a 3x7 grid (3 spatial pixel intervals, 7 scan/mirror step intervals), and integrated for time intervals of [1.088, 1.674,1.674, 1.674, 1.674, 1.674, 1.488] seconds, finishing at scan/mirror steps [ 31, 26, 53, 80, 107, 134, 158]. The first 32 steps are on the limb (1.088 = 32x0.034 seconds/ limb step), whereas the next six intervals are distributed across the 32 disk scan steps.
Units
counts
Structure
Size
21
Description
Dimensions: [21,n] - where 21 is the number of background count pixels, or NumBackgroundCountPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
Support
Parameter #11
Name
Data Quality Indicator
ParameterKey
DQI
Description
Data quality indicator stored as bit-encoded integers where Bit 7: 1 = Negative Radiance, 0 = positive; Bit 6: 1 = Zero Radiance, 0 = non-zero; Bit 5: 1 = Geolocation error (disk pixel on limb or limb pixel on disk), 0 = correct geolocation; Bit 4: 1 = Calibration failure, 0 = No calibration failure; Bits 0-3 are unused.
Units
unitless
Structure
Size
5 14 32
Description
Dimensions: [5,14,32,n] - where 5 is the number of colors, or NumColors; 14 is the number of along track pixels, or NumAlongTrackPixels; 32 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
Support
Parameter #12
Name
Background Star At Pixel Indicator
ParameterKey
BackgroundStarAtPixel
Description
Background Star At Pixel Indicator stored as integers: 1 = true; 0 = false.
Units
unitless
Structure
Size
14 32
Description
Dimensions: [14,32,n] - where 14 is the number of along track pixels, or NumAlongTrackPixels; 32 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
ValidMin
0
ValidMax
1
Support
Parameter #13
Name
Tangent Point Latitude
ParameterKey
TangentPointLatitude
Description
Tangent Point Latitude
Units
degrees
Structure
Size
14 32
Description
Dimensions: [14,32,n] - where 14 is the number of along track pixels, or NumAlongTrackPixels; 32 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
ValidMin
-90.0
ValidMax
90.0
Support
Parameter #14
Name
Tangent Point Longitude
ParameterKey
TangentPointLongitude
Description
Tangent Point Longitude
Units
degrees
Structure
Size
14 32
Description
Dimensions: [14,32,n] - where 14 is the number of along track pixels, or NumAlongTrackPixels; 32 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
ValidMin
-180.0
ValidMax
180.0
Support
Parameter #15
Name
Tangent Point Altitude
ParameterKey
TangentPointAltitude
Description
Tangent Point Altitude
Units
kilometers
Structure
Size
14 32
Description
Dimensions: [14,32,n] - where 14 is the number of along track pixels, or NumAlongTrackPixels; 32 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
Support
Parameter #16
Name
Zenith Angle
ParameterKey
ZenithAngle
Description
Zenith Angle
Units
degrees
Structure
Size
14 32
Description
Dimensions: [14,32,n] - where 14 is the number of along track pixels, or NumAlongTrackPixels; 32 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
Support
Parameter #17
Name
Right Ascension
ParameterKey
RA
Description
Right Ascension
Structure
Size
14 32
Description
Dimensions: [14,32,n] - where 14 is the number of along track pixels, or NumAlongTrackPixels; 32 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
Support
Parameter #18
Name
Declination
ParameterKey
DEC
Description
Declination
Structure
Size
14 32
Description
Dimensions: [14,32,n] - where 14 is the number of along track pixels, or NumAlongTrackPixels; 32 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
Support
Parameter #19
Name
Calibration Error
ParameterKey
CalibrationError
Description
Calibration error
Units
Percent scaled by 10
UnitsConversion
1e-1>%
Structure
Size
5 14 32
Description
Dimensions: [5,14,32,n] - where 5 is the number of colors, or NumColors; 14 is the number of along track pixels, or NumAlongTrackPixels; 32 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
ValidMin
0
ValidMax
1000
Support
Parameter #20
Name
Counting Statistical Error
ParameterKey
CountError
Description
Count error
Caveats
If Bit 6 of Data Quality Indicator (DQI) parameter is set, then set the value returned is in units of Rayleighs/count (unscaled)
Units
Percent scaled by 10
UnitsConversion
1e-1>%
Structure
Size
5 14 32
Description
Dimensions: [5,14,32,n] - where 5 is the number of colors, or NumColors; 14 is the number of along track pixels, or NumAlongTrackPixels; 32 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
ValidMin
0
Support
Parameter #21
Name
Solar Zenith Angle
ParameterKey
SolarZenithAngle
Description
Solar Zenith Angle
Units
degrees
Structure
Size
14 32
Description
Dimensions: [14,32,n] - where 14 is the number of along track pixels, or NumAlongTrackPixels; 32 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
Support
Parameter #22
Name
Imaging Mode Limb Radiance Data
ParameterKey
RadianceData
Description
Radiance scans of nominally 14 pixels along track and 32 pixels crosstrack for each of 5 colors (1216, 1304, 1356 A, LBH1 and LBH2).
Units
Rayleighs
Structure
Size
5 14 32
Description
Dimensions: [5,14,32,n] - where 5 is the number of colors, or NumColors; 14 is the number of along track pixels, or NumAlongTrackPixels; 32 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file.
Wave
WaveType
Electromagnetic
WaveQuantity
Wavelength
WavelengthRange
SpectralRange
Ultraviolet
Low
121.6
High
180.0
Units
nm
Bin
BandName
HI (121.6)
Low
121.6
High
121.6
Bin
BandName
OI (130.4)
Low
130.4
High
130.4
Bin
BandName
OI (135.6)
Low
135.6
High
135.6
Bin
BandName
N2 Lyman-Birge-Hopfield (LBH (1))
Low
140
High
150
Bin
BandName
N2 Lyman-Birge-Hopfield (LBH (2))
Low
165
High
180
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