{ "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_3_1.xsd", "Version": "2.3.1", "NumericalData": { "ResourceID": "spase://GBO/NumericalData/AWESOME/VLF/PT0.02S", "ResourceHeader": { "ResourceName": "AWESOME receiver system narrowband VLF data", "DOI": "https://doi.org/10.48322/6t7b-s324", "ReleaseDate": "2020-09-28T21:24:52Z", "Description": "Most of the data is collected on two air-core loop\n antennas, oriented orthogonal, to collect the two horizontal\n components of the magnetic field. The north-south, or N/S antenna\n is sensitive mostly to waves arriving from the north of from the\n south direction, meaning it picks up the magnetic field component\n in the east-west direction. The other antenna is the east-west\n antenna, which is the opposite. \n\n Narrowband data are the amplitudes and phase of specific\n frequencies, usually corresponding to VLF transmitters that are\n used for communications and navigation. Sampling rate is usually\n either 1 Hz or 50 Hz. They are also useful as a diagnostic of the\n ionosphere. Most of these transmitters use minimum shift keying\n (MSK) modulation, and the recording software extracts the\n amplitude, and the phase is calculated by demodulating the MSK\n demodulation. Details of the demodulation algorithm and examples of\n its application can be found in Gross, N.C.; Cohen, M.B.; Said,\n R.K.; Golkowski, M, \"Polarization of Narrowband VLF\n Transmitter Signals as Ionospheric Diagnostic\", JGR, 2018,\n 901-917. https://doi.org/10.1002/2017JA024907\n\n\n Narrowband files available in the WALDO archive are in 24-hour blocks, so the start\n time of all files is 00:00:00 UT, and the end time is 24:00:00\n UT. Even if only a small amount amount of data was recorded on a\n given day, the file on WALDO will contain 24-hours worth of\n samples. This is done to make the analysis easier, since all files\n have the same start time. The raw original data actually starts a\n new set of files whenever the computer or software reboots, but\n the archivists made the effort of stitching them together. Where data were\n not actually recorded, the value will be “NaN” or not a number. \n\n\n ", "Acknowledgement": "\n DATA USAGE POLICY\nThe data in the WALDO database have been collected by Stanford\nUniversity, the Georgia Institute of Technology, and the University of\nColorado Denver. Funding has been provided by the United States\ngovernment under various basic science research grants over many\nyears. \n\nTo maximize the benefit of those investments, WALDO data are released\nwithout restriction, and can be freely analyzed or published. \n\nThe curators of WALDO are Morris Cohen (Georgia Tech) and Mark\nGolkowski (CU-Denver). We request that the following acknowledgement\nbe added in any publication using data from WALDO \n\n\"VLF data are provided by the WALDO database (http://waldo.world),\noperated jointly by the Georgia Institute of Technology, and the\nUniversity of Colorado Denver, using data collected from those\ninstitutions as well as Stanford University, and has been supported by\nvarious US government grants from the NSF, NASA, and the Department of\nDefense.\" \n\nIf extensive amounts of WALDO data are used in a publication, the\ncurators request, but do not require, to be contacted to discuss the\npossibility of joint authorship, with the WALDO curators providing\nhelp analyzing and interpreting the large dataset. \n ", "PublicationInfo": { "Authors": "Morris B. Cohen, Umran S. Inan, Mark A. Golkowski", "PublicationDate": "2020-01-01T00:00:00Z", "PublishedBy": "Worldwide Archive of Low frequency Data and Observations (WALDO)" }, "Contact": { "PersonID": "spase://SMWG/Person/Morris.Cohen", "Role": "ArchiveSpecialist" }, "InformationURL": { "Name": "Worldwide Archive of Low-Frequency Data and Observations (WALDO)", "URL": "http://waldo.world" } }, "AccessInformation": { "RepositoryID": "spase://SMWG/Repository/WALDO", "AccessURL": { "Name": "Worldwide Archive of Low-Frequency Data and Observations (WALDO) Narrowband Data", "URL": "http://waldo.world/narrowband-data/" }, "Format": "MATLAB_4", "Acknowledgement": "VLF data are provided by the WALDO database (http://waldo.world), operated jointly by the Georgia Institute of Technology, and the University of Colorado Denver, using data collected from those institutions as well as Stanford University, and has been supported by various US government grants from the NSF, NASA, and the Department of Defense." }, "InstrumentID": "spase://SMWG/Instrument/AWESOME/VLF", "MeasurementType": "Waves.Passive", "TemporalDescription": { "TimeSpan": { "StartDate": "2005-04-28T00:00:00", "RelativeStopDate": "-P3Y", "Note": "Different stations have different start/stop dates" }, "Cadence": "P1D" }, "ObservedRegion": [ "Earth.NearSurface", "Earth.NearSurface.Ionosphere" ], "Parameter": [ { "Name": "start_year", "Support": { "SupportQuantity": "Temporal" } }, { "Name": "start_month", "Support": { "SupportQuantity": "Temporal" } }, { "Name": "start_day", "Support": { "SupportQuantity": "Temporal" } }, { "Name": "start_hour", "Support": { "SupportQuantity": "Temporal" } }, { "Name": "start_minute", "Support": { "SupportQuantity": "Temporal" } }, { "Name": "start_second", "Support": { "SupportQuantity": "Temporal" } }, { "Name": "latitude", "Support": { "SupportQuantity": "Positional" } }, { "Name": "longitude", "Support": { "SupportQuantity": "Positional" } }, { "Name": "altitude", "Support": { "SupportQuantity": "Positional" } }, { "Name": "Fs", "Description": "Sampling rate of the data, usually 100 kHz or 1 MHz. ", "CadenceMin": "PT0.000001S", "CadenceMax": "PT0.00001S", "Support": { "SupportQuantity": "Other" } }, { "Name": "gps_quality", "Support": { "SupportQuantity": "DataQuality" } }, { "Name": "adc_channel_number", "Support": { "SupportQuantity": "Other" } }, { "Name": "adc_sn", "Support": { "SupportQuantity": "Other" } }, { "Name": "adc_type", "Support": { "SupportQuantity": "Other" } }, { "Name": "antenna_bearings", "Support": { "SupportQuantity": "Orientation" } }, { "Name": "antenna_description", "Support": { "SupportQuantity": "InstrumentMode" } }, { "Name": "cal_factor", "Support": { "SupportQuantity": "Other" } }, { "Name": "computer_sn", "Support": { "SupportQuantity": "Other" } }, { "Name": "gps_sn", "Support": { "SupportQuantity": "Other" } }, { "Name": "hardware_description", "Support": { "SupportQuantity": "InstrumentMode" } }, { "Name": "is_broadband", "Support": { "SupportQuantity": "InstrumentMode" } }, { "Name": "station_description", "Support": { "SupportQuantity": "Other" } }, { "Name": "station_name", "Support": { "SupportQuantity": "Other" } }, { "Name": "VERSION", "Support": { "SupportQuantity": "Other" } }, { "Name": "is_amp", "Support": { "SupportQuantity": "Other" } }, { "Name": "is_msk", "Support": { "SupportQuantity": "Other" } }, { "Name": "Fc", "Description": "the center frequency of the VLF transmitter (for\n narrowband data)", "Support": { "SupportQuantity": "Other" } }, { "Name": "call_sign", "Support": { "SupportQuantity": "Other" } }, { "Name": "filter_taps", "Support": { "SupportQuantity": "Other" } }, { "Name": "data", "Wave": { "WaveType": "Electromagnetic", "WaveQuantity": "ACMagneticField", "FrequencyRange": { "SpectralRange": "RadioFrequency", "Low": "0.3", "High": "50", "Units": "kHz" } } } ] } } }