<_Note>Nodes prefixed with a _ are not valid SPASE, but are included for debugging. Values prefixed with a x_ are not valid SPASE but may considered for addition for completeness. 2.6.1 <_MasterURL>https://cdaweb.gsfc.nasa.gov/pub/software/cdawlib/0JSONS/de_uv_sai_00000000_v01.json (from all.xml) spase://NASA/NumericalData/DE1/SAI/PT3M <_ResourceID>Source: https://github.com/rweigel/cdawmeta-spase/blob/main/ResourceID.json DE-1 Spin-scan Auroral Imager (SAI) Ultraviolet Images <_ResourceName>Source: Master/CDFglobalAttributes/Logical_source_description de_uv_sai <_AlternateName>Source: Master/CDFglobalAttributes/Logical_source Instrument functional description: The spin-scan auroral imagers (SAI) comprise three photometers which provide images of Earth at various wavelengths via interference filters mounted on a wheel and selected by ground command. Two of the photometers provide visible wavelength images, and the third provides images at vacuum-ultraviolet wavelengths. The three photometers are mounted on the spacecraft such that their fields of view are separated by about 120 degrees in a plane oriented perpendicular to the spin axis. Each photometer in operation collects one scan line during each spacecraft rotation, with an internal mirror stepping once per rotation to start a new scan line. An auroral image is a nadir-centered two-dimensional pixel array provided by the spacecraft rotation and the photometer's stepping mirror which advances the field of view 0.25 degrees once per rotation in a direction perpendicular to the plane of rotation. A change in mirror- stepping direction signals the start of a new image. One, two, or three photometers may be in operation at one time. The images from all operating photometers are telemetered simultaneously with image repetition rates that typically vary from about 3 to 12 minutes. One of the three imaging photometers is equipped with filters and a photocathode for observations at vacuum-ultraviolet wavelengths, in particular emissions of the Lyman-Birge-Hopfield band of molecular nitrogen at about 140 to 170 nm. Imaging at these wavelengths allows coverage of the auroral oval in both the dark and sunlit ionospheres. The filter array for the vacuum-ultraviolet imaging photometer also includes filters for atomic hydrogen Lyman alpha at 121.6 nm and oxygen lines at 130.4 and 135.6 nm. The full width of the fields of view of the photometers corresponding to a single pixel is 0.29 degrees. An image frame consists of all scan lines obtained by mirror steps in one direction which deflect the field of view by 0.25 degrees per rotation. The angular separation of two consecutive pixels in the direction of spacecraft rotation is about 0.23 degrees. A full frame has 120 scan lines or 30 degrees of width. For routine processing the angular width along a scan line is 150 pixels, or about 34.5 degrees of length. The frame width is occasionally adjusted to less than 120 scan lines. Reference: Frank, L. A., J. D. Craven, K. L. Ackerson, M. R. English, R. H. Eather, and R. L. Carovillano, Global auroral imaging instrumentation for the Dynamics Explorer mission, Space Sci. Inst., 5, 369-393, 1981. Data set description: Each DE SAI UV image CDF contains all of images collected by the UV photometer during one day of operations. The displayable image counts are in variable 3. Coordinates are calculated for each position of the image count array. These coordinates are in variables 14, 15, and 16. To facilitate viewing of the images, a mapping of pixel value to a recommended color table based on the characteristics of the selected filter will be included with each image. See the description of variables 17, 18, and 19 below. A relative intensity scale is provided by the uncompressed count table of variable 20. Approximate intensity levels in kiloRayleighs are given in the intensity table of variable 21. Other variables provide orbit and attitude data and information about the selected filter and the mirror stepping direction. Variable descriptions: 1,2. Start time The time assigned to an image is the start time of the initial scan line within a resolution of one second. 3. Image counts Image pixel counts range from 0 to 255. They are stored in a two- dimensional byte array of 121 columns by 150 rows. Each column contains one scan line. Images will generally not fill all of the 121 columns. When an image is displayed with row 1 at the top and column 1 on the left, the spacecraft spin axis is oriented to the left in the display, and the orbit normal vector is oriented to the right. 4. Filter Twelve filters are available for ultra-violet imaging; the filter number, 1-12, is given here. In addition, the peak wavelength in Angstroms is given for the selected filter. 5. Presumed altitude of emissions The presumed altitude of the emissions seen in the image varies with the characteristics of the filter used. 6,7. First and last mirror location counters (MLCs) The MLC range is from 28 in column 1 (leftmost) to 148 in column 121 (rightmost). The direction of mirror stepping motion is shown by comparing first and last MLCs. 8. Orbit/attitude time Whenever possible, the approximate center time of the image is used for determining the orbit and attitude parameters. If O/A data is not available for the center time, the closest available O/A time is used. 9. Spacecraft position vector, GCI 10. Spacecraft velocity vector, GCI 11. Spacecraft spin axis unit vector, GCI 12. Sun position unit vector, GCI 13. Orbit normal unit vector, GCI 14. Geographic longitude or right ascension East longitude is given for each image pixel on the Earth at the altitude given in variable 5. When the pixel altitude is greater than the value of variable 5, the right ascension is given. 15. Geographic latitude or declination North latitude is given for each image pixel on the Earth at the altitude given in variable 5. When the pixel altitude is greater than the value of variable 5, the declination is given. 16. Pixel altitude For each image pixel on the Earth, the presumed altitude of the emissions is used. This is equal to the value of variable 5. For each pixel off the Earth, the altitude of the line of sight is used. 17. Pixel UT This array gives the start time for the collection of each image pixel. 18. RGB color table This is the recommended color table to be used with the limits given in variables 19 and 20. 19,20. Low and high color mapping limits The low and high color limits are recommended for remapping the color table entries, as follows: For pixel values less than the low limit, use the color at table position 1. For pixel values greater than or equal to the low limit and less than or equal to the high limit, use the color at table position (pix-low)/(high-low) x 255 + 1. For pixel values greater than the high limit, use the color at table position 256. 21. Expanded count table The image pixel counts are quasi-logarithmically compressed to the range 0-255. This table gives the average of the uncompressed range for each compressed count value. Table entries 1-128 correspond to compressed counts 0-127 respectively. Count levels greater than 127 are considered overflow. 22. Intensity table For each of the twelve filters, approximate intensity levels in kiloRayleighs are given for each compressed count value. Table entries 1-128 correspond to compressed counts 0-127 respectively. No count conversion data is available for count levels greater than 127. Supporting software: Directions for obtaining supporting software is available on the SAI website at the URL http://www-pi.physics.uiowa.edu/www/desai/software/. Included is an IDL program that displays the images with the recommended color bar and provides approximate intensities and coordinate data for each pixel. <_Description>Source: Master/CDFglobalAttributes/TEXT <_Rights> SPDX Creative Commons Zero v1.0 Universal https://spdx.org/licenses/CC0-1.0.html https://spdx.org/licenses/ Dynamics Explorer Spin-Scan Auroral Imager ultraviolet camera images https://doi.org/10.48322/t7ya-6231 <_DOI>Source: https://github.com/rweigel/cdawmeta-spase/blob/main/DOI.json <_AccessInformation>Source: https://github.com/rweigel/cdawmeta-spase/blob/main/AccessInformation.json 1981-09-23T19:02:17Z 1991-02-18T09:50:31Z <_TemporalDescription>Generated from all.xml/@timerange_start and all.xml/@timerange_stop PT12M7.224S <_Cadence>Counts based on variable 'Epoch' in https://cdaweb.gsfc.nasa.gov/sp_phys/data/de/de1/images_sai/uv_sai_cdaweb/1981/de_uv_sai_19810923_v01.cdf. The most common cadence, 727224 [ms] = PT12M7.224S, occurred for 19.0476% of the 4 timesteps. <_ObservedRegion>Source: https://github.com/rweigel/cdawmeta-spase/blob/main/ObservedRegion.json <_ProcessingLevel>Processing level is not available in the master file; it should be there instead of, say, https://github.com/rweigel/cdawmeta-spase/blob/main/ProcessingLevel.json spase://SMWG/Instrument/DynamicsExplorer1/SAI ImageIntensity spase://SMWG/Repository/NASA/GSFC/SPDF Online Open SPDF/CDAWeb. Please also acknowledge the data producer: Louis A. Frank at The Univ. of Iowa HTTPS from SPDF https://cdaweb.gsfc.nasa.gov/pub/data/de/de1/images_sai/uv_sai_cdaweb In CDF via HTTP from CDAWeb de_uv_sai_%Y%m%d_%Q.cdf %Y DE_UV_SAI CDF spase://SMWG/Repository/NASA/GSFC/SPDF Online Open SPDF/CDAWeb. Please also acknowledge the data producer: Louis A. Frank at The Univ. of Iowa FTPS from SPDF ftps://cdaweb.gsfc.nasa.gov/pub/data/de/de1/images_sai/uv_sai_cdaweb In CDF via HTTP from CDAWeb de_uv_sai_%Y%m%d_%Q.cdf %Y DE_UV_SAI CDF spase://SMWG/Repository/NASA/GSFC/SPDF Online Open SPDF/CDAWeb. Please also acknowledge the data producer: Louis A. Frank at The Univ. of Iowa CDAWeb Web Service https://cdaweb.gsfc.nasa.gov/WebServices/ Instructions for using web services to access this dataset an other other metadata and options for CDAWeb datasets. The ProductKey here corresponds to the query parameter 'dataset' in the tables at the AccessURL in a dataset-related request can be made. DE_UV_SAI CDF CSV GIF NetCDF PNG PS PDF XML x_Script.IDL x_Script.Python Text.ASCII x_WAV spase://SMWG/Repository/NASA/GSFC/SPDF Online Open SPDF/CDAWeb. Please also acknowledge the data producer: Louis A. Frank at The Univ. of Iowa CDAWeb Web Service user interface https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?index=sp_phys&dataset=DE_UV_SAI DE_UV_SAI Web service user interface for this product. CDF GIF PDF Text.ASCII x_WAV spase://SMWG/Repository/NASA/GSFC/SPDF Online Open SPDF/CDAWeb. Please also acknowledge the data producer: Louis A. Frank at The Univ. of Iowa CDAWeb Python Script https://cdaweb.gsfc.nasa.gov/WS/cdasr/1/dataviews/sp_phys/datasets/DE_UV_SAI/clientLibraryExample/ DE_UV_SAI Web service that generates a Python script to access this product. x_Script.IDL x_Script.Python spase://SMWG/Repository/NASA/GSFC/SPDF Online Open SPDF/SSCWeb. Please also acknowledge the data producer: Louis A. Frank at The Univ. of Iowa 4D Orbit Viewer https://sscweb.gsfc.nasa.gov/4dorbit/?sc=DE_UV_SAI DE_UV_SAI Web Service to this product. HTML spase://SMWG/Repository/NASA/GSFC/SPDF Online Open SPDF/CDAWeb and the HAPI project. Please also acknowledge the data producer: Louis A. Frank at The Univ. of Iowa CDAWeb HAPI Server https://hapi-server.org/servers/#server=CDAWeb&dataset=DE_UV_SAI DE_UV_SAI Web Service to this product using the HAPI interface. CSV JSON Binary spase://SMWG/Repository/NASA/GSFC/SPDF Online Open SPDF/CDAWeb and the HAPI project. Please also acknowledge the data producer: Louis A. Frank at The Univ. of Iowa CDAWeb HAPI Script in Multiple Languages https://hapi-server.org/servers/#server=CDAWeb&dataset=DE_UV_SAI&return=script DE_UV_SAI Web Service user interface that generates scripts in IDL, Javascript, MATLAB, Python, Autoplot, curl, wget to access this product. See https://hapi-server.org/servers/api for the API. x_Script.IDL x_Script.Javascript x_Script.MATLAB x_Script.Python x_Script.Autoplot x_Script.curl x_Script.wget spase://SMWG/Repository/NASA/GSFC/SPDF Online Open SPDF/CDAWeb and the HAPI project. Please also acknowledge the data producer: Louis A. Frank at The Univ. of Iowa HAPI visualizations https://hapi-server.org/plot/?server=https://cdaweb.gsfc.nasa.gov/hapi&dataset=DE_UV_SAI&format=gallery DE_UV_SAI Web Service that generates plots. See https://hapi-server.org/plot/ for the API. PNG PDF SVG Dynamics Explorer 1 (from all.xml/observatory/description/@short) Spin-Scan Auroral Imager (from all.xml/instrument/description/@short) Space Physics (from Master/CDFglobalAttributes/Discipline) Magnetospheric Science (from Master/CDFglobalAttributes/Discipline) DE-1 (from Master/CDFglobalAttributes/Source_name) Dynamics Explorer 1 (from Master/CDFglobalAttributes/Source_name) UV (from Master/CDFglobalAttributes/Data_type) Ultraviolet Images (from Master/CDFglobalAttributes/Data_type) SAI (from all.xml/instrument/@ID) Earth.NearSurface.Atmosphere Earth.NearSurface.Ionosphere Earth.Magnetosphere.Plasmasphere Earth.Magnetosphere.Polar START TIME (Epoch) Epoch CATDESC: 'Image center time, Epoch'. Notes not in Master CDF: 'The units are the units in CDF files. For other web services, this variable is may be represented as a time string.' ms Scalar Temporal START TIME Time_PB5 Master CDF CATDESC: 'Image start time, PB5'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' -2147483648 3 year day msec Image Pixel Counts Image_Counts Master CDF CATDESC: 'Ultraviolet Image (quasi-logarithmically compressed counts)'. Master CDF VAR_NOTES: 'Image_Counts contains the displayable image in 121 columns by 150 rows of pixels. Most images will use 120 of the columns. The counts have been quasi-logarithmically compressed by the instrument. Approximate uncompressed value for Image_Counts(i,j) is ExpandedCount(Image_Counts(i,j)+1). Approximate intensity in kR is Intens_Table(Image_Counts(i,j)+1).The appearance of the actual count value 255 is rare. When displaying an image,it works best to use the fill value as an overflow (i.e. brightest) value.'. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' Counts 255 121 150 Image Pixel Counts Image_CountsM Master CDF CATDESC: ' --> Ultraviolet Mapped Image (quasi-logarithmically compressed counts)'. Master CDF VAR_NOTES: 'Image_Counts contains the displayable image in 121 columns by 150 rows of pixels. Most images will use 120 of the columns. The counts have been quasi-logarithmically compressed by the instrument. Approximate uncompressed value for Image_Counts(i,j) is ExpandedCount(Image_Counts(i,j)+1). Approximate intensity in kR is Intens_Table(Image_Counts(i,j)+1).The appearance of the actual count value 255 is rare. When displaying an image,it works best to use the fill value as an overflow (i.e. brightest) value.'. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' Counts 255 121 150 Filter number and wavelength Filter Master CDF CATDESC: 'Filter number and peak wavelength in Angstroms)'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' -2147483648 2 number Angstroms Presumed Altitude of Emissions AltF Master CDF CATDESC: 'Presumed altitude of emissions, km.'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' Kilometers -1e+31 First Mirror Location Counter First_MLC Master CDF CATDESC: 'Mirror location counter at time of first scan'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' Mirror steps -2147483648 Last Mirror Location Counter Last_MLC Master CDF CATDESC: 'Mirror location counter at time of last scan'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' Mirror steps -2147483648 ORBIT/ATTITUDE TIME OA_time_PB5 Master CDF CATDESC: 'Orbit/attitude time, PB5'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' -2147483648 3 year day msec Spacecraft position GCI SC_Pos_GCI Master CDF CATDESC: 'GCI position vector of DE spacecraft in kilometers.'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' km -1e+31 3 Spacecraft velocity GCI SC_Vel_GCI Master CDF CATDESC: 'GCI velocity vector of DE spacecraft in km/sec.'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' Kilometers/second -1e+31 3 Spacecraft spin axis GCI SC_SpinV_GCI Master CDF CATDESC: 'GCI spin axis unit vector of DE spacecraft.'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' 1 -1e+31 3 Sun Vector GCI Sun_Vctr_GCI Master CDF CATDESC: 'GCI unit vector toward sun'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' 1 -1e+31 3 Orbit Normal Vector GCI Orb_Normal_GCI Master CDF CATDESC: 'GCI unit vector of DE orbit normal'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' 1 -1e+31 3 Geo E Long (off Earth: Rt Asc GeoLng_RAs Master CDF CATDESC: 'Geographic longitudes, or Right Ascensions'. Master CDF VAR_NOTES: 'Geographic east longitude for every image pixel on the Earth, right ascension for every pixel off the Earth'. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' Degrees -1e+31 121 150 Geo N Lat (off Earth: Declination GeoLat_Dec Master CDF CATDESC: 'Geographic latitudes, or Declinations'. Master CDF VAR_NOTES: 'Geographic north latitude for every image pixel on the Earth, declination for every pixel off the Earth'. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' Degrees -1e+31 121 150 Pixel Altitudes Pixel_Alts Master CDF CATDESC: 'Altitudes of pixels, km.'. Master CDF VAR_NOTES: 'Presumed altitude of emissions for every pixel on the Earth, equal to the value of the variable AltF; altitude of line of sight for every pixel off the Earth'. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' Kilometers -1e+31 121 150 Pixel UTs Pixel_UTs_PB5 Master CDF CATDESC: 'Pixel collection times, PB5'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' -2147483648 3 121 150 year day msec Color Limit Low Limit_Lo Master CDF CATDESC: 'Lower limit for remapping color table to pixel range (see TEXT)'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' Counts -32768 Color Limit High Limit_Hi Master CDF CATDESC: 'Upper limit for remapping color table to pixel range (see TEXT)'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' Counts -32768 Image header Image_Header Master CDF CATDESC: 'Image header words'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' -2147483648 101 Scan line headers Scan_Headers Master CDF CATDESC: 'Scan line header words'. Master CDF VAR_NOTES: ''. Notes not in Master CDF: 'The time index (the ISTP DEPEND_0 variable) for this parameter is Epoch.' -32768 12 121