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/NumericalData/TIMED/GUVI/Imaging/L1B_Disk NASA NumericalData TIMED GUVI Imaging Level 1B Disk 2025-12-04T13:32:05Z 2021-06-02T00:00:00Z Only known prior ReleaseDate of the metadata 2025-11-14T16:01:52Z Added PublicationInfo. Added ResourceType and NamingAuthority. Changed http to https in top-level schemaLocation attribute. Fixed version number separator in top-level schemaLocation attribute. Matched version number in schemaLocation attribute to updated value in Version tag. ZCB 2025-12-04T13:32:05Z Added MetadataRightsList. Updated to 2.7.1. ZCB Level 1B Disk data contains calibrated radiance data over multiple scans that are geolocated into a GUVI-based coordinate system on the disk. NASA, Andrew B. Christensen Christensen, Andrew B. 2025-11-14T16:01:52Z Johns Hopkins University Applied Physics Laboratory spase://SMWG/Person/Andrew.B.Christensen PrincipalInvestigator L1B Imaging Data Information http://guvitimed.jhuapl.edu/sites/default/files/data/documents/L1B_datainfo.pdf spase://VITMO/NumericalData/TIMED/GUVI/Imaging/L1B_Disk spase://VSPO/NumericalData/TIMED/GUVI/Imaging/L1B_Disk spase://SMWG/Repository/TIMED/GUVI_POC Online Open GUVI POC L1B Imaging Data Request http://guvitimed.jhuapl.edu/data_fetch_l1b_imaging This web page allows the request of data files for this product. To request data: select the year and day then press display. NetCDF GZIP NASA, Andrew B. Christensen Calibrated GUVI Imaging L1B Disk data Level 1B 009 spase://SMWG/Instrument/TIMED/GUVI Radiance 2002-01-07T00:00:00.000 2007-12-11T00:05:38.000 Earth.NearSurface.Thermosphere Earth.NearSurface.Ionosphere Earth.NearSurface.AuroralRegion TIMED GUVI Imaging Disk lower thermosphere ionosphere MLTI Starting Time Starting_Time Starting date/time of file's observation encoded in a 13-digit string and stored as a single netCDF global attribute. yyyydoyhhmmss 1 Dimensions: [1] - this parameter is a single element per file. Temporal Stopping Time Stopping_Time Stopping date/time of file's observation encoded in a 13-digit string and stored as a single netCDF global attribute. yyyydoyhhmmss 1 Dimensions: [1] - this parameter is a single element per file. Temporal Day of Year DOY Date of observation in number of days since start of current year. days 0 Dimensions: [n] - where n is the number of scans, or NumScans, (i.e., records) in an orbital file. 1 366 Temporal Time Time Time of observation in integral number of milliseconds since start of current day. Timestamp marks beginning of interval ms 1e-3>s 0 Dimensions: [n] - where n is the number of scans, or NumScans, (i.e., records) in an orbital file. 0 86399999 Temporal Detector Detector Detector number of detector being used unitless 0 Dimensions: [n] - where n is the number of scans, or NumScans, (i.e., records) in an orbital file. 1 2 Other Slit position Slit Slit position being used where 0 = closed, 1 = wide, 2 = medium, 3 = narrow, and 4 = unknown. unitless 0 Dimensions: [n] - where n is the number of scans, or NumScans, (i.e., records) in an orbital file. 0 4 InstrumentMode Mirror start position MirrorStartPosition Starting position of the mirror. unitless 0 Dimensions: [n] - where n is the number of scans, or NumScans, (i.e., records) in an orbital file. 49 53 Other Mirror nadir position MirrorNadirPosition Position of the mirror when at nadir. unitless 0 Dimensions: [n] - where n is the number of scans, or NumScans, (i.e., records) in an orbital file. 249 253 Other Dark count pixels DarkCountPixels 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. 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. counts 4 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. Other Background count pixels BackgroundPixels 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 159 disk scan steps. counts 21 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. Other Data Quality Indicator DQI Data quality indicator 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. unitless 5 14 159 Dimensions: [5,14,159,n] - where 5 is the number of colors, or NumColors; 14 is the number of along track pixels, or NumAlongTrackPixels; 159 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file. Other Pierce point latitude PiercePointLatitude Pierce point latitude geographic coordinates degrees 14 159 Dimensions: [14,159,n] - where 14 is the number of along track pixels, or NumAlongTrackPixels; 159 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file. -90.0 90.0 Positional Pierce point longitude PiercePointLongitude Pierce point longitude geographic coordinates degrees 14 159 Dimensions: [14,159,n] - where 14 is the number of along track pixels, or NumAlongTrackPixels; 159 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file. -180.0 180.0 Positional Calibration Error CalibrationError Calibration error Percent scaled by 10 1e-1>% 5 14 159 Dimensions: [5,14,159,n] - where 5 is the number of colors, or NumColors; 14 is the number of along track pixels, or NumAlongTrackPixels; 159 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file. 0 1000 Other Counting Statistical Error CountError Count error If Bit 6 of Data Quality Indicator (DQI) parameter is set, then set the value returned is in units of Rayleighs/count (unscaled) Percent scaled by 10 1e-1>% 5 14 159 Dimensions: [5,14,159,n] - where 5 is the number of colors, or NumColors; 14 is the number of along track pixels, or NumAlongTrackPixels; 159 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file. 0 Other Solar Zenith Angle SolarZenithAngle Solar Zenith Angle degrees 14 159 Dimensions: [14,159,n] - where 14 is the number of along track pixels, or NumAlongTrackPixels; 159 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file. Other Imaging Mode Disk Radiance Data RadianceData Radiance scans of nominally 159 pixels crosstrack and 14 pixels along track for each of 5 colors (1216, 1304, 1356 A, LBH1 and LBH2). Rayleighs 5 14 159 Dimensions: [5,14,159,n] - where 5 is the number of colors, or NumColors; 14 is the number of along track pixels, or NumAlongTrackPixels; 159 is the number of across track pixels, or NumAcrossTrackPixels; n is the number of scans, or NumScans, (i.e., records) in an orbital file. Electromagnetic Wavelength Ultraviolet 121.6 180.0 nm HI (121.6) 121.6 121.6 OI (130.4) 130.4 130.4 OI (135.6) 135.6 135.6 N2 Lyman-Birge-Hopfield (LBH (1)) 140 150 N2 Lyman-Birge-Hopfield (LBH (2)) 165 180