HPDE.io

Voyager 1 Planetary Radio Astronomy (PRA) Highband Receiver Jupiter encounter, 48 sec resolution

ResourceID
spase://NASA/NumericalData/Voyager1/PRA/Jupiter/High/PT48S

Description

Voyager 1 Planetary Radio Astronomy (PRA) Highband receiver daily files during Jupiter Encounter (1979-02-01 to 1979-04-13). Associated with these binary data are a series of quick-look GIF spectrogram plots created using the binary data. The plots are available for both polarization channels. These binary data were also converted into IDL save sets. The data set provides 48 second resolution highband radio mean power data in units of millibels. The high-band receiver consisted of 128 channels of 200 kHz bandwidth each, with center frequencies spaced at 307.2 kHz intervals from 1.2 MHz to 40.4 MHz. The highband receiver was designed especially for the observation of Jovian decametric radio emissions. The PRA radiometer was usually operated routinely in the so-called POLLO sweeping mode, in which all 198 frequency channels of the high- and low-band receivers together were swept in 6 sec, dwelling at each channel for 25 msec. From one step to the next in the channel switching sequence, the antenna polarization sense was reversed, i.e., was changed from RH to LH or vice versa. Thus the time required for making a measurement of both the RH and LH intensity components at both senses of elliptical polarization at a given frequency was 12 sec. The data consists of successive averages of 4 pairs of RH and LH intensity measurements, each average spanning an interval of 48 sec. The format of these binary data files is as follows: file separation variable year, month, day information millisecond decimal value of the day Integer array (128,2) for 128 left and right channels (NOTE 128 channels for Hi-band; 70 channels for Lo-band) file separation variable There is an IDL program that reads these files into an IDL-format save set. See Information URL for a link to this file. The data are calibrated and are given in units of 'millibels' which is 1000 times the log of the received power. Zero millbels corresponds to approximately 1.4 x 10^-21 W m^-2 Hz^-1, however, this value is never seen in practice. The minimum values detected, which includes receiver internal and spacecraft generated noise, are about 2300 to 2400 millibels, or about 3.5 x 10^-19 W m^-2 Hz^-1; even higher values are seen at the very lowest frequencies. Note: The polarization indicated is the received polarization, not necessarily the emitted polarization. Correct interpretation of the received polarization depends on the antenna plane orientation relative to the radio source. A good description of this concept can be found in Leblanc Y., Aubier M. G., Ortega-Molina A., Lecacheux A., 1987, J.Geophys. Res. 92, 15125 and in Wang, L. and Carr, T.D., Recalibration of the Voyager PRA antenna for polarization sense measurement, Astron. Astrophys., 281, 945-954, 1994. and references therein.

View XML | View JSON | Edit

Details

Version:2.3.0

NumericalData

ResourceID
spase://NASA/NumericalData/Voyager1/PRA/Jupiter/High/PT48S
ResourceHeader
ResourceName
Voyager 1 Planetary Radio Astronomy (PRA) Highband Receiver Jupiter encounter, 48 sec resolution
ReleaseDate
2020-07-07 21:15:54Z
Description

Voyager 1 Planetary Radio Astronomy (PRA) Highband receiver daily files during Jupiter Encounter (1979-02-01 to 1979-04-13). Associated with these binary data are a series of quick-look GIF spectrogram plots created using the binary data. The plots are available for both polarization channels. These binary data were also converted into IDL save sets. The data set provides 48 second resolution highband radio mean power data in units of millibels. The high-band receiver consisted of 128 channels of 200 kHz bandwidth each, with center frequencies spaced at 307.2 kHz intervals from 1.2 MHz to 40.4 MHz. The highband receiver was designed especially for the observation of Jovian decametric radio emissions. The PRA radiometer was usually operated routinely in the so-called POLLO sweeping mode, in which all 198 frequency channels of the high- and low-band receivers together were swept in 6 sec, dwelling at each channel for 25 msec. From one step to the next in the channel switching sequence, the antenna polarization sense was reversed, i.e., was changed from RH to LH or vice versa. Thus the time required for making a measurement of both the RH and LH intensity components at both senses of elliptical polarization at a given frequency was 12 sec. The data consists of successive averages of 4 pairs of RH and LH intensity measurements, each average spanning an interval of 48 sec. The format of these binary data files is as follows: file separation variable year, month, day information millisecond decimal value of the day Integer array (128,2) for 128 left and right channels (NOTE 128 channels for Hi-band; 70 channels for Lo-band) file separation variable There is an IDL program that reads these files into an IDL-format save set. See Information URL for a link to this file. The data are calibrated and are given in units of 'millibels' which is 1000 times the log of the received power. Zero millbels corresponds to approximately 1.4 x 10^-21 W m^-2 Hz^-1, however, this value is never seen in practice. The minimum values detected, which includes receiver internal and spacecraft generated noise, are about 2300 to 2400 millibels, or about 3.5 x 10^-19 W m^-2 Hz^-1; even higher values are seen at the very lowest frequencies. Note: The polarization indicated is the received polarization, not necessarily the emitted polarization. Correct interpretation of the received polarization depends on the antenna plane orientation relative to the radio source. A good description of this concept can be found in Leblanc Y., Aubier M. G., Ortega-Molina A., Lecacheux A., 1987, J.Geophys. Res. 92, 15125 and in Wang, L. and Carr, T.D., Recalibration of the Voyager PRA antenna for polarization sense measurement, Astron. Astrophys., 281, 945-954, 1994. and references therein.

Acknowledgement
When using delivered data please acknowledge the data provider.
Contacts
RolePersonStartDateStopDateNote
1.PrincipalInvestigatorspase://SMWG/Person/James.W.Warwick
2.MetadataContactspase://SMWG/Person/Todd.A.King
InformationURL
Name
PPI/PDS PRA Instrument catalog file PRAINST.CAT
URL
Description

Information about the PRA instrument on the Voyager mission including operational mode descriptions.

InformationURL
Name
Planetary Radio Astronomy (PRA)
URL
Description

NSSDC Master Catalog description of the Voyager 1 PRA Instrument

InformationURL
Name
IDL program - convertvoyHIband
URL
Description

An IDL program that will read these Voyager PRA highband binary files and convert to IDL save sets.

PriorIDs
spase://VWO/NumericalData/Voyager1/PRA/VG1_PRA_High_Jupiter_PT48S
spase://VWO/NumericalData/Voyager1/PRA/Jupiter/High.PT48S
spase://VSPO/NumericalData/Voyager1/PRA/Jupiter/High/PT48S
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
Access to Voyager 1 and 2 PRA Highband 48 second binary data files
URL
Description

Within this directory list are the binary data files for Voyager 1 and 2 PRA highband.

Language
en
Format
Binary
Encoding
None
Acknowledgement
When using delivered data please acknowledge the data provider.
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
HTTPS from SPDF
URL
Description

Within this directory list are the IDL save sets for Voyager 1 PRA highband during Jupiter encounter.

Language
en
Format
IDL
Encoding
None
Acknowledgement
When using delivered data please acknowledge the data provider.
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
PDS/PPI
URL
ProductKey
VG1-J-PRA-4-SUMM-BROWSE-48SEC-V1.0
Description

This collection is archived with NASA's Planetary Data System.

Language
En
Format
Text.ASCII
Acknowledgement
NASA's Planetary Plasma Interactions (PPI) Node of the Planetary Data System (PDS) and the P.I. for the data.
InstrumentIDs
MeasurementType
Waves.Passive
MeasurementType
Spectrum
MeasurementType
ElectricField
MeasurementType
MagneticField
TemporalDescription
TimeSpan
StartDate
1979-02-01 00:00:00Z
StopDate
1979-04-13 23:59:59Z
Cadence
PT48S
SpectralRange
RadioFrequency
ObservedRegion
Jupiter
ObservedRegion
Heliosphere.Outer
Keywords
Dynamic Spectrogram
Spectrogram
Jupiter
Decametric Radio Emission
DAM
Parameter #1
Name
Date
Description

Year, month, and day of start in the format YYMMDD

Support
SupportQuantity
Temporal
Parameter #2
Name
Millisecond
Description

Milliseconds of day

Units
ms
Support
SupportQuantity
Temporal
Parameter #3
Name
Spectral Power
Description

Electric field power spectral density, an average of 8 sweeps of the PRA highband receiver of 128 frequency channels each.

Units
millibels
Wave
WaveType
PlasmaWaves
WaveQuantity
ACElectricField
FrequencyRange
SpectralRange
RadioFrequency
Low
1.2
High
40.4
Units
MHz