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IMAGE Radio Plasma Imager (RPI) Daily Dynamic Spectrogram Plot

ResourceID
spase://NASA/DisplayData/IMAGE/RPI/DS/P1D

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.

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Details

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
2021-07-19 14:39:57Z
RevisionHistory
RevisionEvent
ReleaseDate
2021-07-19 14:39:57Z
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.
Contacts
RolePersonStartDateStopDateNote
1.PrincipalInvestigatorspase://SMWG/Person/Bodo.W.Reinisch
2.DataProducer
TechnicalContact
spase://SMWG/Person/Ivan.A.Galkin
InformationURL
Name
IMAGE RPI Instrument Page
URL
Description

IMAGE RPI Instrument page maintained by NASA GSFC with RPI facts, description, team, data, documents, discoveries, and related links sections

Language
en
InformationURL
Name
IMAGE RPI Instrument Page at UML
URL
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
AssociationType
DerivedFrom
Association
AssociationID
AssociationType
DerivedFrom
PriorIDs
spase://VWO/DisplayData/IMAGE/RPI/GIF_DS_PT5M
spase://VWO/DisplayData/IMAGE/RPI/DS.P1D
spase://VSPO/DisplayData/IMAGE/RPI/DS/P1D
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
RPI Daily Dynamic Spectrograms
URL
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.
InstrumentIDs
MeasurementType
Waves.Passive
MeasurementType
Spectrum
MeasurementType
ElectricField
TemporalDescription
TimeSpan
StartDate
2000-04-21 20:24:42Z
StopDate
2005-12-18 07:50:00Z
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
ObservedRegion
Earth.NearSurface.Plasmasphere
ObservedRegion
Earth.NearSurface.AuroralRegion
ObservedRegion
Earth.NearSurface.PolarCap
ObservedRegion
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.
Keywords
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
Parameter #1
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
Qualifier
Pseudo
WaveQuantity
ACElectricField
FrequencyRange
SpectralRange
RadioFrequency
Low
3
High
1009
Units
kHz