{ "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", "DisplayData": { "ResourceID": "spase://NASA/DisplayData/IMAGE/RPI/DS/P1D", "ResourceHeader": { "ResourceName": "IMAGE Radio Plasma Imager (RPI) Daily Dynamic Spectrogram Plot", "ReleaseDate": "2021-07-19T14:39:57Z", "RevisionHistory": { "RevisionEvent": { "ReleaseDate": "2021-07-19T14:39:57Z", "Note": "Changed an Input Resource ID from VSPO to NASA" } }, "Description": "Collection of RPI Daily Dynamic Spectrogram plots at NASA GSFC, covering complete mission period from 2000-04-21 to 2005-12-18. Dynamic Spectrograms present the time history of natural radio emissions in space between 3 and 1009 kHz while the IMAGE spacecraft orbits the Earth. This operating frequency range was selected by the RPI team to provide an optimal temporal resolution to the wave observations. Each image is a daily plot of the voltage spectral density of received signal (color scale) as function of operating frequency (vertical axis) and time (horizontal axis). Commonly used in the analysis of noise generators, spectral density is a frequency-dependent characteristic that describes how much power is generated by the emission source in a 1 Hz bandwidth. RPI Dynamic Spectograms plot a Voltage Spectral Density, which is root of power spectral density, measured in [V/root-Hz] units. Note that conversion of antenna voltage to electric field strength depends on effective length of receive antennas, and such conversion is not performed here. RPI is capable of detecting input radio emissions above its noise floor of 5 nV/root-Hz, which is determined by the internal white noise of the RPI antenna pre-amplifiers.", "Acknowledgement": "Users please acknowledge B. W. Reinisch of the University of Massachusetts Lowell and J. L. Green of the NASA Goddard Space Flight Center for making these dynamic spectrograms available.", "Contact": [ { "PersonID": "spase://SMWG/Person/Bodo.W.Reinisch", "Role": "PrincipalInvestigator" }, { "PersonID": "spase://SMWG/Person/Ivan.A.Galkin", "Role": [ "DataProducer", "TechnicalContact" ] } ], "InformationURL": [ { "Name": "IMAGE RPI Instrument Page", "URL": "https://image.gsfc.nasa.gov/rpi/", "Description": "IMAGE RPI Instrument page maintained by NASA GSFC with RPI facts, description, team, data, documents, discoveries, and related links sections", "Language": "en" }, { "Name": "IMAGE RPI Instrument Page at UML", "URL": "https://ulcar.uml.edu/rpi.html", "Description": "IMAGE RPI Instrument page maintained by University of Massachusetts Lowell with RPI description, team, software downloads, software user guides, access to CORPRAL automated prospecting results, mission planning tools and commanding guide, data model descriptions for Level 0 and 1, sonification files of 2003 Halloween storm, and useful links", "Language": "en" } ], "Association": [ { "AssociationID": "spase://NASA/NumericalData/IMAGE/RPI/PGM/CCSDS/PT5M", "AssociationType": "DerivedFrom" }, { "AssociationID": "spase://NASA/NumericalData/IMAGE/RPI/PGM/CDF/PT5M", "AssociationType": "DerivedFrom" } ], "PriorID": [ "spase://VWO/DisplayData/IMAGE/RPI/GIF_DS_PT5M", "spase://VWO/DisplayData/IMAGE/RPI/DS.P1D", "spase://VSPO/DisplayData/IMAGE/RPI/DS/P1D" ] }, "AccessInformation": { "RepositoryID": "spase://SMWG/Repository/NASA/GSFC", "Availability": "Online", "AccessRights": "Open", "AccessURL": { "Name": "RPI Daily Dynamic Spectrograms", "URL": "https://image.gsfc.nasa.gov/rpi/spectrogram/", "Description": "Repository of RPI dynamic spectrogram images at NASA GSFC, containing web interface to individual images.", "Language": "en" }, "Format": "GIF", "Encoding": "None", "DataExtent": { "Quantity": "200000", "Units": "byte", "Per": "P1D" }, "Acknowledgement": "Users please acknowledge B. W. Reinisch of the University of Massachusetts Lowell and J. L. Green of the NASA Goddard Space Flight Center for making these dynamic spectrograms available." }, "ProcessingLevel": "Calibrated", "ProviderProcessingLevel": "Level 1, calibrated data in physical units. Spacecraft MET to UT is converted using history of IMAGE observatory clock drift. All images produced by PostPro1 software version 1.3.x from raw telemetry data.", "InstrumentID": "spase://SMWG/Instrument/IMAGE/RPI", "MeasurementType": [ "Waves.Passive", "Spectrum", "ElectricField" ], "TemporalDescription": { "TimeSpan": { "StartDate": "2000-04-21T20:24:42Z", "StopDate": "2005-12-18T07:50:00Z", "Note": "In Cadence below, the 5 minutes refers to the nominal interval between measurements used to make up a 24-hour dynamic spectrogram. Display Cadence (further below) refers to the 24-hour interval between the start of two successive dynamic spectrograms." }, "Cadence": "PT5M", "Exposure": "PT72S" }, "SpectralRange": "RadioFrequency", "DisplayCadence": "P1D", "ObservedRegion": [ "Earth.Magnetosphere", "Earth.NearSurface.Plasmasphere", "Earth.NearSurface.AuroralRegion", "Earth.NearSurface.PolarCap", "Heliosphere.Inner" ], "Caveats": "(A) Known artifacts of dynamic spectrograms are (1) a horizontal line at 20 kHz where the frequency stepping changes from linear to logarithmic, and (2) a variety of interference sources internal to the IMAGE observatory appear as horizontal lines on the dynamic spectrograms including, most prominently, 101 kHz; additional lines appear at 63 kHz and its 126 kHz 2nd harmonic (battery charger), at times a broad band is also present between 160 and 200 kHz due to the torque rod operation, and a narrow line appears at 75 kHz due to the S-band transponder. Other known intereferer lines are 150 kHz, 200 kHz, and 240 kHz (deck plate heaters and other onboard instruments), but these lines are usually not present in the measurement. (B) When the spectrogram is plotted, the pixel size is made wide enough to fill the gaps caused by the 5 minute cadence of the measurements. (C) Comparison of voltage spectral density with other space receiver data has to consider differences in the antenna configurations.", "Keyword": [ "Dynamic Spectrogram", "Spectrogram", "AKR", "Auroral hiss", "Auroral Kilometric Radiation", "Chorus", "Continuum radiation", "Myriametric radiation", "Plasmaspheric Hiss", "Solar radio burst", "Terrestrial Kilometric Radiation", "TKR", "Type II Solar radio burst", "Type III Solar radio burst", "UHR", "Upper hybrid resonance", "VLF Station", "VLF Transmitter", "Whistler" ], "InputResourceID": "spase://NASA/NumericalData/IMAGE/RPI/DS/PT5M", "Parameter": { "Name": "Voltage spectral density", "Description": "Commonly used in circuit analysis, Power Spectral Density (PSD) describes how much noise power is generated by the emission source in a 1 Hz bandwidth. Dynamic Specrtograms use Voltage Spectral Density (VSD), which is root of PSD, measured in V/root-Hz units. The VSD in RPI spectrograms is presented in dB relative to 1 V/root-Hz (logarithmic scale), units of dB(V/root-Hz). The RPI instrument noise floor is 5 nV/root-Hz = -166 dB(V/root-Hz) at the receiver input.", "Units": "dB(V/root-Hz)", "Wave": { "WaveType": "PlasmaWaves", "Qualifier": [ "Magnitude", "Pseudo" ], "WaveQuantity": "ACElectricField", "FrequencyRange": { "SpectralRange": "RadioFrequency", "Low": "3", "High": "1009", "Units": "kHz" } } } } } }