{ "Spase": { "xmlns": "http://www.spase-group.org/data/schema", "xmlns:xsi": "http://www.w3.org/2001/XMLSchema-instance", "xsi:schemaLocation": "http://www.spase-group.org/data/schema http://www.spase-group.org/data/schema/spase-2_2_9.xsd", "Version": "2.2.9", "NumericalData": { "ResourceID": "spase://NASA/NumericalData/ISIS2/SFS/Ionogram/PT22S", "ResourceHeader": { "ResourceName": "ISIS 2 Topside Sounder Ionograms", "AlternateName": "ISIS-2 Topside Sounder Ionogram CDFs at NASA's CDAWeb", "ReleaseDate": "2020-07-07T21:14:43Z", "Description": "These ionograms were digitized from the original ISIS-2 7-track analog telemetry tapes using the facilities of the former Data Evaluation Laboratory at the NASA/GSFC. This data restoration project is headed by Dr. R.F. Benson (NASA/GSFC). Ionograms were digitized at the rate of 40,000 16-bit samples/sec. This sample rate is higher than the Nyquist frequency of 30 kHz. The sample frequency of 40 kHz provides a measurement every 25 microseconds corresponding to an apparent range (c*t/2) interval of 3.75 km. Ionograms with this sample rate are designated as \"full\" ionograms because they have the full 3.75 km apparent-range resolution. The ionograms used for most analysis, and those available from CDAWeb, were produced by averaging every four samples of the sounder-receiver video amplitude output to yield an average value every 100 microseconds corresponding to an apparent-range resolution of 15 km. These ionogram files are referred to as \"average\" files with standard resolution. Each ionogram consists of a fixed-frequency and and a swept-frequency portion. The time resolution between ionograms is typically 14 or 22 seconds depending on the frequency sweep range.", "Acknowledgement": "Users please acknowledge the Coordinated Data Analysis Web (CDAWeb) at the NASA Goddard Space Flight Center, ISIS-2 SFS instrument Principal Investigator J. H. Whitteker and ISIS Data-Restoration project lead Robert F. Benson.", "Contact": [ { "PersonID": "spase://SMWG/Person/James.H.Whitteker", "Role": "PrincipalInvestigator" }, { "PersonID": "spase://SMWG/Person/Robert.F.Benson", "Role": "GeneralContact" }, { "PersonID": "spase://SMWG/Person/Dieter.K.Bilitza", "Role": "GeneralContact" } ], "InformationURL": [ { "Name": "ISIS/Alouette Topside Sounder Data Restoration Project", "URL": "https://nssdc.gsfc.nasa.gov/space/isis/isis-status.html", "Description": "ISIS/Alouette page maintained by NASA GSFC with science and instrument descriptions, data access, software, and publication lists", "Language": "en" }, { "Name": "NSSDC's Master Catalog", "URL": "https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=1971-024A-01", "Description": "Information about the Sweep Frequency Sounder experiment on ISIS-2." } ], "PriorID": [ "spase://VWO/NumericalData/ISIS2/SFS/ISIS2_Ionogram_CDF_PT22S", "spase://VWO/NumericalData/ISIS2/SFS/Ionogram.PT22S", "spase://VSPO/NumericalData/ISIS2/SFS/Ionogram/PT22S" ] }, "AccessInformation": { "RepositoryID": "spase://SMWG/Repository/NASA/GSFC/SPDF", "Availability": "Online", "AccessRights": "Open", "AccessURL": [ { "Name": "FTPS from SPDF (not with most browsers)", "URL": "ftps://spdf.gsfc.nasa.gov/pub/data/isis/topside_sounder/ionogram_cdf/isis2/", "Description": "FTP access to repository of ISIS-2 Ionograms in CDF format at NASA CDAWeb. The CDF files are organized by ground station, where each ground station is represented by a three letter ID and a two-digit code. The full names for each station are provided at https://nssdc.gsfc.nasa.gov/space/isis/isis-table1-new.html A merged data set, independent of the ground stations, is planned.", "Language": "en" }, { "Name": "HTTPS from SPDF", "URL": "https://spdf.gsfc.nasa.gov/pub/data/isis/topside_sounder/ionogram_cdf/isis2/", "Description": "HTTPS access to repository of ISIS-2 Ionograms in CDF format at NASA CDAWeb", "Language": "en" }, { "Name": "Subset, plot, list from CDAWeb", "URL": "https://cdaweb.gsfc.nasa.gov/sp_phys/", "Description": "CDAWeb interactive interface for subsets, plots and lists of data" }, { "Name": "Ahmedabad, India", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Ahmedabad/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Ahmedabad, India: AME, Latitude 23, Longitude 73" }, { "Name": "Ascension Island, United Kingdom", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/AscensionIsland/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Ascension Island, United Kingdom: ACN, Latitude -8, Longitude 346" }, { "Name": "Brazzavillle, Congo", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Brazzaville/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Brazzavillle, Congo: BRZ, Latitude -4, Longitude 15" }, { "Name": "Fairbanks, Alaska", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Fairbanks/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Fairbanks, AK: ULA, Latitude 65, Longitude 212" }, { "Name": "Falkland Island, United Kingdom", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/FalklandIslands/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Falkland Island, United Kingdom: SOL, Latitude -52, Longitude 302" }, { "Name": "Johannesburg, South Africa", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Johannesburg/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Johannesburg, South Africa: BUR, Latitude -26, Longitude 28" }, { "Name": "Kashima, Japan", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Kashima/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Kashima, Japan: KSH, Latitude 36, Longitude 141" }, { "Name": "Kerguelen Island, France", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/KerguelenIsland/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Kerguelen Island, France: KER, Latitude -49, Longitude 70" }, { "Name": "Kourou, French Guyana", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Kourou/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Kourou, French Guyana: KRU, Latitude 5, Longitude 307" }, { "Name": "Kwajalein, Marshall Islands", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Kwajalein/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Kwajalein, Marshall Islands: KWA, Latitude 9, Longitude 168" }, { "Name": "Las Palmas, Canary Island, Spain", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/LasPalmas/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Las Palmas, Canary Island, Spain: CNA, Latitude 28, Longitude 345" }, { "Name": "Lauder, New Zealand", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Lauder/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Lauder, New Zealand: LAU, Latitude -45, Longitude 170" }, { "Name": "Orroral, Australia", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Orroral/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Orroral, Australia: ORR, Latitude -36, Longitude 149" }, { "Name": "Ottawa, QC, Canada", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Ottawa/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Ottawa, QC, Canada: OTT, Latitude 45, Longitude 284" }, { "Name": "Ouagadougou, Burkina Faso", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Ouagadougou/PT22S", "Description": "ISIS-1 Topside Sounder Average Ionogram over Ouagadougou, Burkina Faso: ODG, Latitude 14, Longitude 359" }, { "Name": "Quito, Equador", "URL": "https://hpde.io/NASA/NumericalData/ISIS1/SFS/AverageIonogram/Quito/PT29S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Quito, Equador: QUI, Latitude -1, Longitude 281" }, { "Name": "Resolute Bay, NU, Canada", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/ResoluteBay/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Resolute Bay, NU, Canada: RES, Latitude 75, Longitude 265" }, { "Name": "Santiago, Chile", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Santiago/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Santiago, Chile: SNT, Latitude -33, Longitude 298" }, { "Name": "Syowa Base, Antartica", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Sodankyla/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Syowa Base, Antartica: SYO, Latitude -69, Longitude 40" }, { "Name": "Sodankyla, Finland", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/SyowaBase/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Sodankyla, Finland: SOD, Latitude 67, Longitude 27" }, { "Name": "Terre Adelie, Antarctica", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/TerreAdelie/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Terre Adelie, Antarctica: ADL, Latitude -67, Longitude 140" }, { "Name": "Tromso, Norway", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Tromso/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Tromso, Norway: TRO, Latitude 70, Longitude 19" }, { "Name": "Winkfield, United Kingdom", "URL": "https://hpde.io/NASA/NumericalData/ISIS2/SFS/AverageIonogram/Winkfield/PT22S", "Description": "ISIS-2 Topside Sounder Average Ionogram over Winkfield, United Kingdom: WNK, Latitude 51, Longitude 359" } ], "Format": "CDF", "Encoding": "None", "Acknowledgement": "Please acknowledge the CDAWeb team at NASA/GSFC/SPDF" }, "ProcessingLevel": "Calibrated", "InstrumentID": "spase://SMWG/Instrument/ISIS2/SFS", "MeasurementType": [ "Waves.Active", "Spectrum" ], "TemporalDescription": { "TimeSpan": { "StartDate": "1969-01-30T14:50:12Z", "StopDate": "1983-12-30T15:19:33Z", "Note": "Note: The cadence is 14 or 22.5 s for ionograms that have a swept-frequency portion from 0.1 to 10.0 MHz and 0.1 to 20 MHz, respectively." }, "Cadence": "PT22S" }, "SpectralRange": "RadioFrequency", "ObservedRegion": [ "Earth.Magnetosphere", "Earth.Magnetosphere.Polar", "Earth.NearSurface.AuroralRegion", "Earth.NearSurface.PolarCap", "Earth.NearSurface.Ionosphere", "Earth.NearSurface.Ionosphere.Topside" ], "Caveats": "See discussion on \"How To Detect Erroneous ISIS-2 Digital Ionogram Files\" at https://nssdc.gsfc.nasa.gov/space/isis/isis_read_error.html", "Keyword": [ "Ionogram", "topside sounder", "fixed- and swept-frequency sounder", "topside ionosphere", "ionospheric reflections", "ground reflections", "ionospheric echoes", "ground echoes", "ducted echoes", "wave scattering", "field-aligned irregularities", "FAI", "plasma resonance", "plasma waves", "AKR", "solar type III bursts", "upper-hybrid noise band" ], "Parameter": [ { "Name": "satellite ID", "ParameterKey": "satellite", "Description": "sat.-ID: 1=AL1, 2=AL2, 3=ISIS1, 4=ISIS2", "Support": { "SupportQuantity": "Other" } }, { "Name": "telemetry station code", "ParameterKey": "station_id", "Description": "two-digit telemetry station code", "Support": { "SupportQuantity": "Other" } }, { "Name": "transmitter power code", "ParameterKey": "power_code", "Description": "trans. power code: 1=Prim(400W) 2=Sec(400W)", "Support": { "SupportQuantity": "Other" } }, { "Name": "sounder/receiver code", "ParameterKey": "s/r_code", "Description": "sounder/receiver code: 0=off, 1=on", "Support": { "SupportQuantity": "Other" } }, { "Name": "swept frequency range code", "ParameterKey": "f_range_code", "Description": "swept-f range code: 0=normal (swept-frequency from 0.1 to 10.0 MHz), 1=extended (swept-frequency from 0.1 to 20.0 MHz)", "Support": { "SupportQuantity": "Other" } }, { "Name": "DMODE code", "ParameterKey": "DMODE", "Description": "DMODE (transm. on/off for alternate frame pairs): 0=off, 1=on", "Support": { "SupportQuantity": "Other" } }, { "Name": "GMODE code", "ParameterKey": "GMODE", "Description": "GMODE (transmission of alternate frames of fixed-frequency ionograms and normal combined fixed- and swept-frequency ionograms): 0=off, 1=on", "Support": { "SupportQuantity": "Other" } }, { "Name": "sounder mixed mode", "ParameterKey": "mixed_mode", "Description": "sounder mixed mode (transmission at a fixed-frequency while the sounder receiver sweeps over swept-frequency range): 0=off, 1=on", "Support": { "SupportQuantity": "Other" } }, { "Name": "AIT mode", "ParameterKey": "AIT_mode", "Description": "AIT mode (automatic sounder operation every 3 min): 0=off, 1=on", "Support": { "SupportQuantity": "Other" } }, { "Name": "fixed frequency code (0-6)", "ParameterKey": "fix_freq", "Description": "fixed frequency code: 0=off, 1=0.12, 2=0.48, 3=1.00, 4=1.95, 5=4.00, 6=9.303 MHz", "Support": { "SupportQuantity": "Other" } }, { "Name": "Year", "ParameterKey": "year", "Description": "Year of ionogram frame sync in UT", "Support": { "SupportQuantity": "Other" } }, { "Name": "Day of Year", "ParameterKey": "doy", "Description": "Day of Year of ionogram frame sync in UT", "Support": { "SupportQuantity": "Other" } }, { "Name": "Hour", "ParameterKey": "hr", "Description": "Hour of ionogram frame sync in UT", "Support": { "SupportQuantity": "Other" } }, { "Name": "Minute", "ParameterKey": "min", "Description": "Minute of hour of ionogram frame sync in UT", "Support": { "SupportQuantity": "Other" } }, { "Name": "Second", "ParameterKey": "sec", "Description": "Second of minute of ionogram frame sync in UT", "Support": { "SupportQuantity": "Other" } }, { "Name": "Local Mean Time (hh,mm)", "ParameterKey": "LMT", "Description": "Local Mean Time (hh,mm) at time of ionogram frame sync", "Structure": { "Size": "2", "Element": [ { "Name": "LMT(hh)", "Index": "1", "Units": "hrs" }, { "Name": "LMT(mm)", "Index": "2", "Units": "min" } ] }, "Support": { "SupportQuantity": "Other" } }, { "Name": "geog coord (Lat,Long,Hgt)", "ParameterKey": "geo_coord", "Description": "geographic coordinates (Lat,Long,Hgt) at time of ionogram frame sync", "Structure": { "Size": "2", "Element": [ { "Name": "latitude", "Index": "1", "Units": "deg" }, { "Name": "longitude", "Index": "2", "Units": "deg" }, { "Name": "height", "Index": "3", "Units": "km" } ] }, "Support": { "SupportQuantity": "Positional" } }, { "Name": "Geomagnetic Local Time (hh,mm)", "ParameterKey": "GMLMT", "Description": "Geomagnetic Local Time (HHMM) at time of ionogram frame sync", "Structure": { "Size": "2", "Element": [ { "Name": "GMLMT(hh)", "Index": "1" }, { "Name": "GMLMT(mm)", "Index": "2" } ] }, "Support": { "SupportQuantity": "Other" } }, { "Name": "geom latitude", "ParameterKey": "GMLAT", "Description": "geomagnetic latitude at time of ionogram frame sync", "Units": "deg", "Support": { "SupportQuantity": "Positional" } }, { "Name": "geom longitude", "ParameterKey": "GMLONG", "Description": "geomagnetic longitude at time of ionogram frame sync", "Units": "deg", "Support": { "SupportQuantity": "Positional" } }, { "Name": "inv latitude", "ParameterKey": "INV_LAT", "Description": "invariant latitude at time of ionogram frame sync", "Units": "deg", "Support": { "SupportQuantity": "Other" } }, { "Name": "magnetic inclination", "ParameterKey": "DIP", "Description": "Dip angle of mag field direction at time of ionogram frame sync", "Units": "deg", "Support": { "SupportQuantity": "Other" } }, { "Name": "Solar Zenith Angle", "ParameterKey": "CHI", "Description": "Solar Zenith Angle at time of ionogram frame sync", "Units": "deg", "Support": { "SupportQuantity": "Other" } }, { "Name": "L shell (McIlwain parameter)", "ParameterKey": "L", "Description": "L shell (McIlwain parameter) at time of ionogram frame sync", "Support": { "SupportQuantity": "Positional" } }, { "Name": "spacecraft in/out sunlight", "ParameterKey": "sun", "Description": "spacecraft in(=1)/out(=2) sunlight at time of ionogram frame sync", "Support": { "SupportQuantity": "Other" } }, { "Name": "Cyl. Electrost. Probe", "ParameterKey": "CEP", "Description": "CEP instrument on(1)/off(0) status", "Support": { "SupportQuantity": "Other" } }, { "Name": "0.05-30 kHz VLF receiver", "ParameterKey": "VLF", "Description": "VLF receiver on(1)/off(0) status", "Support": { "SupportQuantity": "Other" } }, { "Name": "Retarding Potential Analyzer", "ParameterKey": "RPA", "Description": "RPA instrument on(1)/off(0) status", "Support": { "SupportQuantity": "Other" } }, { "Name": "Ion Mass Spectrometer", "ParameterKey": "IMS", "Description": "IMS instrument on(1)/off(0) status", "Support": { "SupportQuantity": "Other" } }, { "Name": "Soft Particle Spectrometer", "ParameterKey": "SPS", "Description": "SPS instrument on(1)/off(0) status", "Support": { "SupportQuantity": "Other" } }, { "Name": "Energetic Particle Detector", "ParameterKey": "EPD", "Description": "EPD instrument on(1)/off(0) status", "Support": { "SupportQuantity": "Other" } }, { "Name": "Red Line Photometer", "ParameterKey": "RLP", "Description": "RLP instrument on(1)/off(0) status", "Support": { "SupportQuantity": "Other" } }, { "Name": "Auroral Scanning Photometer", "ParameterKey": "ASP", "Description": "ASP instrument on(1)/off(0) status", "Support": { "SupportQuantity": "Other" } }, { "Name": "start of swept-frequency portion", "ParameterKey": "swept_start", "Description": "scan line number of start of swept-frequency portion of the ionogram - separates the fixed- and swept-frequency portions", "Support": { "SupportQuantity": "Other" } }, { "Name": "times of ionogram frequency markers", "ParameterKey": "Time_mark", "Description": "msec after frame sync - time of frequency markers", "Units": "ms", "Structure": { "Size": "22" }, "ValidMin": "3000.0", "ValidMax": "30000.0", "Support": { "SupportQuantity": "Temporal" } }, { "Name": "values of ionogram frequency markers", "ParameterKey": "freq_mark", "Description": "ionogram frequency markers", "Units": "MHz", "Structure": { "Size": "22" }, "ValidMin": "0.1", "ValidMax": "20.0", "Support": { "SupportQuantity": "Other" } }, { "Name": "number of delay times per ionogram scan-line", "ParameterKey": "vh_num", "Description": "each sounder-pulse transmission is followed by a scan of the sounder-receiver video amplitude output values for each delay time monitored after the transmitted pulse; these scans are called scan lines. There are two types of ISIS-2 binary ionogram files, one designated as \"full\" and one as \"average\" The full file has 892 delay times (one every 0.025ms). The average files are derived from the full files by averaging the amplitude values in 4 delay-time bins. Thus the average binary files contain 223 time-delay bins within each scan line. The cdf files were made from these average binary files.", "Support": { "SupportQuantity": "Other" } }, { "Name": "number of ionogram scan-line frequencies", "ParameterKey": "f_num", "Description": "Ionogram files can be of different length. In some the swept-frequency portion covers the range 0.1 - 10 MHz, in others 0.1 - 20 MHz. Also, the proper start of each ionogram file, marked by a frame-sync pulse, was not always detected during the analog-to-digital (A/D) conversion. In such cases a frame sync was inserted to limit the file size. Thus the number of sounder-receiver video amplitude vs. delay time scan lines per ionogram can vary.", "Support": { "SupportQuantity": "Other" } }, { "Name": "delay-time values", "ParameterKey": "delay_time", "Description": "delay-time values used in each scan line", "Units": "msec", "Structure": { "Size": "223" }, "ValidMin": "0.0", "ValidMax": "23.0", "Support": { "SupportQuantity": "Other" } }, { "Name": "apparent-range values", "ParameterKey": "v_height", "Description": "apparent-range values used in each scan line", "Units": "km", "Structure": { "Size": "223" }, "ValidMin": "0.0", "ValidMax": "3333.33", "Support": { "SupportQuantity": "Other" } }, { "Name": "Time", "ParameterKey": "Epoch", "Description": "Time", "Units": "ms", "Support": { "SupportQuantity": "Temporal" } }, { "Name": "sounder receiver video amplitude", "ParameterKey": "ampl", "Description": "The color scale represents a linear sounder-receiver video amplitude output range from zero to 4.5 V expressed in terms of telemetry units from zero to 255. This calibration is based on the video calibration levels at the end of the listening period following each sounder pulse (these calibration levels produce the multi-colored stripe at the bottom of the digital ionograms). The sounder-receiver automatic-gain-control (AGC) voltage (from 0 to 5.12 volts) is obtained from a linear interpolation between the AGC trace displayed between 2400 km virtual range (16.0 ms) as 5.12 V and either 2805 km (18.7 ms) on the average ionograms or 2801.25 km (18.675 ms) on the full ionograms2805 km (18.7 ms) as 0 volts. On the average ionograms, which are available as either CDF or binary files from the NSSDC, the range resolution is 0.1 ms (corresponding to a virtual-range resolution of 15 km) there are 28 rows (27 intervals) covering the 0 to 5.12 V range; thus each row in virtual range above (decreasing delay time) the zero level (at 18.7 ms delay time) corresponds to an increase of 5.12/27 V of AGC with a quantization uncertainty of approximately plus or minus 0.1 V. Two rows have zero video-output amplitude values (on the average ionograms) in order that a clear AGC trace is visible on the ionograms. The row with the greatest virtual range corresponds to the actual AGC value. These AGC values were obtained from the pcm data corresponding to the ionogram of interest; these pcm files are available from the NSSDC. If the ionogram analysis program (also available from the NSSDC) is used, the AGC voltage corresponding to the scaling of each X- and O-mode trace point is given as part of the output file with the extension .tra. On the full ionograms, which are available as binary files from the NSSDC, the range resolution is 0.025 ms (corresponding to a virtual-range resolution of 3.75 km) and three rows have zero video-output amplitude values; the middle row corresponds to the actual AGC value.", "Structure": { "Size": "223" }, "ValidMin": "0", "ValidMax": "255", "Wave": { "WaveType": "PlasmaWaves", "Qualifier": [ "Magnitude", "Pseudo" ], "WaveQuantity": "Intensity", "FrequencyRange": { "SpectralRange": "RadioFrequency", "Low": "0.1", "High": "20", "Units": "MHz" } } }, { "Name": "scan-line frequency", "ParameterKey": "freq", "Description": "frequency of each scan line; in the swept-frequency portion of the ionogram they correspond to interpolated values between the frequency markers", "Units": "MHz", "ValidMin": "0.1", "ValidMax": "20.0", "Support": { "SupportQuantity": "Other" } }, { "Name": "Electron Gyrofrequency", "ParameterKey": "FH", "Description": "Electron Gyrofrequency at time of ionogram frame sync", "Units": "MHz", "Support": { "SupportQuantity": "Other" } } ] } } }