Data Set Information
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| DATA_SET_NAME |
VG2 URA PLS DERIVED RDR ELECTRON FIT 48SEC V1.0
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| DATA_SET_ID |
VG2-U-PLS-5-RDR-ELEFIT-48SEC-V1.0
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| NSSDC_DATA_SET_ID |
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| DATA_SET_TERSE_DESCRIPTION |
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| DATA_SET_DESCRIPTION |
This data set contains electron parameters in the PLS energy range (10-5950 eV) at Uranus during the Voyager 2 encounter. Parameters are calculated in several ways. Total moment density and temperature are given. Each electron spectrum is also fit with a thermal component and 1-3 hot components depending on how many Maxwellians are needed to fit the entire distribution. The moment density and temperature of the hot component is calculated after the thermal component is subtracted from the spectrum. The CHI-Square value for each fit is given. The spacecraft charge is not calculated consistently, and may result in factor of 2-3 errors in the thermal electron density. Data is unreliable inside 5 RU and in the occultation regions. At Uranus measurements were taken using both a long and a short integration time. Each 48 SEC measurement frame contained either an E1-Short and an E2-Long measurement or an E2-Short and an EI-Long. To reduce systematic errors, complete electron spectra were obtained only by combining two long or two short spectra. The instrument threshold is at a density of about 0.001 CM-3; thus fits which yield data close to this value should be treated with caution. Flags in the data indicate whether the full analysis could be performed and if the data was contaminated by LECP stepping. A complete description of this data set is in Sittler et al. (1987). THE PARAMETER DEFINITIONS ARE: NAME TYPE DEFINITION TIME A*24 YR,MON,DAY,HR,MIN,SEC,MSEC IFLY ' Flag = 0 for Cruise, 1 for Magnetosphere, -2 for rough moment estimate only, -5 for no analysis LECPF ' Flag = 1 for LECP contamination, 0 otherwise EDATA(1) R*4 THBN(angle between DCUP normal and B vector) 2 ' RNE moment electron density (/CM**3) 3 ' RTE ' ' temperature (eV) 4 ' PHISC spacecraft potential (Volts) 5 ' RNC cold electron density (/CM**3) 6 ' SGNC standard deviation of RNC (/CM**3) 7 ' RTC cold electron temperature (eV) 8 ' SGTC standard deviation of RTC (eV) 9 ' CHIC CHI-Square of cold fit 10 ' RNH1 1st hot electron density (/CM**3) 11 ' SGNH1 standard deviation of RNH1 (/CM**3) 12 ' TH1 1st hot electron temperature (eV) 13 ' SGTH1 standard deviation of TH1 (eV) 14 ' CHIH1 CHI-Square of 1st hot fit 15 ' RNH2 2nd hot electron density (/CM**3) 16 ' SGNH2 standard deviation of RNH2 (/CM**3) 17 ' TH2 2nd hot electron temperature (eV) 18 ' SGTH2 standard deviation of th2 (eV) 19 ' CHIH2 CHI-Square of 2nd hot fit 20 ' RNH3 3rd hot electron density (/CM**3) 21 ' SGNH3 standard deviation of RNH3 (/CM**3) 22 ' TH3 3rd hot electron temperature (eV) 23 ' SGTH3 standard deviation of TH3 (eV) 24 ' CHIH3 CHI-square of 3rd hot fit 25 ' CHI CHI-Square for total fit 26 ' RNH moment hot electron density (/CM**3) 27 ' RTH moment hot electron temperature (eV) In computing RNH1,TH1 we used the 3rd to 7th channels above the breakpoint energy EB1 and subtracted the cold component FC from FE (observed) before doing the fit. In reality this fit was done iteratively between the cold and hot component fits (FC=FE-FH and FH=FE-FC etc.). A similar approach was used in computing RNH3,TH3 for which a Maxwellian fit was done to those channels above EB2. The parameters RNH2,TH2 were fit to the upper 5 (3 MIN) channels (generally above EB2). This fit was primarily done to allow proper estimation of FE to the high energy portion of the spectrum. In many cases there are not sufficient points to compute RNH3,TH3 AND RNH2,TH2 do provide a fair representation of the spectrum. If RNH1=RNH2=RNH3 then you should not use the 2nd and 3rd fit parameters. Values of 1.E32 indicate that the parameter could not be obtained from the data using the standard analysis technique. Additional information about this dataset and the instrument which produced it can be found elsewhere in this catalog. An overview of the data in this data set can be found in Sittler et al. (1987) and a complete instrument description can be found in Bridge (1977).
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| DATA_SET_RELEASE_DATE |
1993-02-01T00:00:00.000Z
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| START_TIME |
1986-01-24T07:06:31.204Z
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| STOP_TIME |
1986-01-24T11:59:19.137Z
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| MISSION_NAME |
VOYAGER
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| MISSION_START_DATE |
1972-07-01T12:00:00.000Z
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| MISSION_STOP_DATE |
N/A (ongoing)
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| TARGET_NAME |
URANUS
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| TARGET_TYPE |
PLANET
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| INSTRUMENT_HOST_ID |
VG2
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| INSTRUMENT_NAME |
PLASMA SCIENCE EXPERIMENT
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| INSTRUMENT_ID |
PLS
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| INSTRUMENT_TYPE |
PLASMA INSTRUMENT
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| NODE_NAME |
planetary plasma interactions
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| ARCHIVE_STATUS |
ARCHIVED
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| CONFIDENCE_LEVEL_NOTE |
This data set provides an estimate of the electron parameters in the PLS energy range (10-5950 eV). The thermal electron parameters may be underestimated in some regions due to negative spacecraft charging which is not corrected for. Electron parameters may also be unreliable between 1736 and 1854 SCET on Jan 24 where electron temperatures are below the instrument energy threshold. Between 1920 and 2150 SCET on Jan 24 The spacecraft had a large (several hundred volt) negative potential, so electron parameters in this region should also be treated with caution. The instrument threshold for detecting electrons is a density of about 0.001 CM-3. At times when the density is near this value all derived parameters are suspect. From 1621 to 1649 on Jan. 24 sunlight created an artificial signal so this data should be discarded. The LECP stepper motor is also creates a spurious signal in the PLS detector; times when this occurs are flagged. SAMPLING_PARAMETER_NAME = TIME SAMPLING_PARAMETER_RESOLUTION = 48.000000 MINIMUM_SAMPLING_PARAMETER = N/A MAXIMUM_SAMPLING_PARAMETER = N/A SAMPLING_PARAMETER_INTERVAL = 48.000000 MINIMUM_AVAILABLE_SAMPLING_INT = 48.000000 SAMPLING_PARAMETER_UNIT = SECOND DATA_SET_PARAMETER_NAME = ELECTRON DENSITY NOISE_LEVEL = N/A DATA_SET_PARAMETER_UNIT = CM-3 SAMPLING_PARAMETER_NAME = TIME SAMPLING_PARAMETER_RESOLUTION = 48.000000 MINIMUM_SAMPLING_PARAMETER = N/A MAXIMUM_SAMPLING_PARAMETER = N/A SAMPLING_PARAMETER_INTERVAL = 48.000000 MINIMUM_AVAILABLE_SAMPLING_INT = 48.000000 SAMPLING_PARAMETER_UNIT = SECOND DATA_SET_PARAMETER_NAME = ELECTRON TEMPERATURE NOISE_LEVEL = N/A DATA_SET_PARAMETER_UNIT = CM-3
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| CITATION_DESCRIPTION |
Richardson, J.D., VG2-U-PLS-5-RDR-ELEFIT-48SEC-V1.0, VG2 URA PLS DERIVED RDR ELECTRON FIT 48SEC V1.0, NASA Planetary Data System, 1993.
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| ABSTRACT_TEXT |
This data set contains electron parameters in the PLS energy range (10-5950 eV) at Uranus during the Voyager 2 encounter. Parameters are calculated in several ways. Total moment density and temperature are given. Each electron spectrum is also fit with a thermal component and 1-3 hot components depending on how many Maxwellians are needed to fit the entire distribution. The moment density and temperature of the hot component is calculated after the thermal component is subtracted from the spectrum. The CHI-Square value for each fit is given. The spacecraft charge is not calculated consistently, and may result in factor of 2-3 errors in the thermal electron density. Data is unreliable inside 5 RU and in the occultation regions. At Uranus measurements were taken using both a long and a short integration time. Each 48 SEC measurement frame contained either an E1-Short and an E2-Long measurement or an E2-Short and an EI-Long. To reduce systematic errors, complete electron spectra were obtained only by combining two long or two short spectra. The instrument threshold is at a density of about 0.001 CM-3; thus fits which yield data close to this value should be treated with caution. Flags in the data indicate whether the full analysis could be performed and if the data was contaminated by LECP stepping. A complete description of this data set is in Sittler et al. (1987).
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| PRODUCER_FULL_NAME |
JOHN D. RICHARDSON
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| SEARCH/ACCESS DATA |
Planetary Plasma Interactions Website
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