Data Set Information
|
| DATA_SET_NAME |
VOYAGER 1 JUPITER PLASMA DERIVED ION MOMENTS 96 SEC
|
| DATA_SET_ID |
VG1-J-PLS-5-ION-MOM-96.0SEC
|
| NSSDC_DATA_SET_ID |
|
| DATA_SET_TERSE_DESCRIPTION |
|
| DATA_SET_DESCRIPTION |
Data Set Overview : THIS DATA SET CONTAINS THE BEST ESTIMATES OF THE TOTAL ION DENSITY AT JUPITER DURING THE VOYAGER 1 ENCOUNTER IN THE PLS VOLTAGE RANGE (10-5950 EV/Q). IT IS CALCULATED USING THE METHOD OF MCNUTT ET AL. (1981) WHICH TO FIRST ORDER CONSISTS OF TAKING THE TOTAL MEASURED CURRENT AND DIVIDING BY THE COLLECTOR AREA AND PLASMA BULK VELOCITY. THIS METHOD IS ONLY ACCURATE FOR HIGH MACH NUMBER FLOWS DIRECTLY INTO THE DETECTOR, AND MAY RESULT IN UNDERESTIMATES OF THE TOTAL DENSITY OF A FACTOR OF 2 IN THE OUTER MAGNETOSPHERE. THUS ABSOLUTE DENSITIES SHOULD BE TREATED WITH CAUTION, BUT DENSITY VARIATIONS IN THE DATA SET CAN BE TRUSTED. THE LOW RESOLUTION MODE DENSITY IS USED BEFORE 1979 63 1300, AFTER THIS THE LARGER OF THE HIGH AND LOW RESOLUTION MODE DENSITIES IN A 96 SEC PERIOD IS USED SINCE THE L-MODE SPECTRA OFTEN ARE SATURATED. COROTATION IS ASSUMED INSIDE L:17.5, AND A CONSTANT VELOCITY COMPONENT OF 200 KM/S INTO THE D CUP IS USED OUTSIDE OF THIS. THESE ARE THE DENSITIES GIVEN IN THE MCNUTT ET AL. (1981) PAPER CORRECTED BY A FACTOR OF 1.209 (.9617) FOR DENSITIES OBTAINED FROM THE SIDE (MAIN) SENSOR. THIS CORRECTION IS DUE TO A BETTER CALCULATION OF THE EFFECTIVE AREA OF THE SENSORS. DATA FORMAT: COLUMNS 1-6 ARE TIME (YEAR, DAY, HOUR, MIN, SEC, MSEC) COLUMN 7 IS THE MOMENT DENSITY IN CM-3. EACH ROW HAS FORMAT (6I4, E12.3). 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 MCNUTT ET AL. (1981) AND A COMPLETE INSTRUMENT DESCRIPTION CAN BE FOUND IN BRIDGE (1977). Processing Level Id : 5 Software Flag : Y Parameters : Sampling Parameter Name : TIME Data Set Parameter Name : ION DENSITY Sampling Parameter Resolution : 96.000000 Sampling Parameter Interval : 96.000000 Minimum Available Sampling Int : 96.000000 Data Set Parameter Unit : EV Sampling Parameter Unit : SECOND Description ----------- A derived parameter equaling the number of ions per unit volume over a specified range of ion energy, energy/charge, or energy/nucleon. Discrimination with regard to mass and or charge state is necessary to obtain this quantity, however, mass and charge state are often assumed due to instrument limitations. Many different forms of ion density are derived. Some are distinguished by their composition (N+, proton, ion, etc.) or their method of derivation (Maxwellian fit, method of moments). In some cases, more than one type of density will be provided in a single dataset. In general, if more than one ion species is analyzed, either by moment or fit, a total density will be provided which is the sum of the ion densities. If a plasma component does not have a Maxwellian distribution the actual distribution can be represented as the sum of several Maxwellians, in which case the density of each Maxwellian is given. Source Instrument Parameters : Instrument Host ID : VG1 Data Set Parameter Name : ION DENSITY Instrument Parameter Name : ION RATE Important Instrument Parameters : 1 Instrument Host ID : VG1 Data Set Parameter Name : ION DENSITY Instrument Parameter Name : ION CURRENT Important Instrument Parameters : 1 Instrument Host ID : VG1 Data Set Parameter Name : ION DENSITY Instrument Parameter Name : PARTICLE MULTIPLE PARAMETERS Important Instrument Parameters : 1 Processing : Processing History ------------------ Source Data Set ID : VG1-PLS Software : MOMANAL Product Data Set ID : VG1-J-PLS-5-ION-MOM-96.0SEC Software 'MOMANAL' ------------------ Software Name : MOMANAL Software Type : PIN Software Release Date : N/A Node ID : N/A Cognizant Engineer : N/A Software Access Description : N/A
|
| DATA_SET_RELEASE_DATE |
1988-08-01T00:00:00.000Z
|
| START_TIME |
1979-03-01T12:04:12.474Z
|
| STOP_TIME |
1979-03-05T04:45:54.608Z
|
| MISSION_NAME |
VOYAGER
|
| MISSION_START_DATE |
1972-07-01T12:00:00.000Z
|
| MISSION_STOP_DATE |
N/A (ongoing)
|
| TARGET_NAME |
JUPITER
|
| TARGET_TYPE |
PLANET
|
| INSTRUMENT_HOST_ID |
VG1
|
| INSTRUMENT_NAME |
PLASMA SCIENCE EXPERIMENT
|
| INSTRUMENT_ID |
PLS
|
| INSTRUMENT_TYPE |
PLASMA ANALYZER
|
| NODE_NAME |
Planetary Plasma Interactions
|
| ARCHIVE_STATUS |
ARCHIVED
|
| CONFIDENCE_LEVEL_NOTE |
Overview : THIS DATA SET PROVIDES AN ESTIMATE OF THE POSITIVE ION CHARGE DENSITY. SEVERAL ASSUMPTION ARE MADE TO SIMPLIFY THE ANALYSIS; THESE MAY AFFECT THE ACCURACY OF THE RESULTS. HIGH MACH NUMBER FLOW IS ASSUMED; MACH NUMBERS OF 2-3, WHICH ARE REASONABLE LOWER LIMITS FOR HEAVY IONS, RESULT IN 10-20% UNDERESTIMATES OF THE CHARGE DENSITY. THE ANALYSIS ASSUMES A UNIT RESPONSE (IE., ALL PARTICLES IN A COLD BEAM INCIDENT ON THE APERTURE OF THE EXPERIMENT WOULD BE MEASURED AT THE COLLECTOR). THE ACTUAL RESPONSE IS DOCUMENTED IN MCNUTT ET AL. (1981) AND CAN BE AS LOW AS 70%. A VELOCITY INTO THE DETECTOR MUST ALSO BE ASSUMED; THE VELOCITY USED IS THE COROTATION VELOCITY INSIDE OF 17.5 RJ AND 200 KM/S OUTSIDE OF THIS. THIS VELOCITY PROFILE IS IN ACCORD WITH THAT MEASURED WHERE VELOCITY DETERMINATIONS ARE POSSIBLE, BUT THE USE OF INCORRECT VALUES GIVE ERRORS IN THE DENSITY WHICH VARY LINEARLY WITH ERRORS IN THE VELOCITY. FINALLY, ONLY IONS IN THE PLS ENERGY RANGE (10-5950 EV/Q) ARE COUNTED. THE CUMULATIVE ERROR FROM ALL THESE EFFECTS IS LESS THAN 10% IN THE SOLAR WIND, LESS THAN A FACTOR OF TWO IN THE OUTER MAGNETOSPHERE (R>20 RJ) AND LESS THAN 20-30% INSIDE OF THIS. SINCE THE AMPLITUDE OF EACH OF THESE EFFECTS VARIES SLOWLY IN TIME (DISTANCE), THE RELATIVE CHANGES IN DENSITY ARE GOOD TO A FEW PERCENT IN MOST CASES.
|
| CITATION_DESCRIPTION |
Citation TBD
|
| ABSTRACT_TEXT |
THIS DATA SET CONTAINS THE BEST ESTIMATES OF THE TOTAL ION DENSITY AT JUPITER DURING THE VOYAGER 1 ENCOUNTER IN THE PLS VOLTAGE RANGE (10-5950 EV/Q). IT IS CALCULATED USING THE METHOD OF MCNUTT ET AL. (1981) WHICH TO FIRST ORDER CONSISTS OF TAKING THE TOTAL MEASURED CURRENT AND DIVIDING BY THE COLLECTOR AREA AND PLASMA BULK VELOCITY. THIS METHOD IS ONLY ACCURATE FOR HIGH MACH NUMBER FLOWS DIRECTLY INTO THE DETECTOR, AND MAY RESULT IN UNDERESTIMATES OF THE TOTAL DENSITY OF A FACTOR OF 2 IN THE OUTER MAGNETOSPHERE. THUS ABSOLUTE DENSITIES SHOULD BE TREATED WITH CAUTION, BUT DENSITY VARIATIONS IN THE DATA SET CAN BE TRUSTED. THE LOW RESOLUTION MODE DENSITY IS USED BEFORE 1979 63 1300, AFTER THIS THE LARGER OF THE HIGH AND LOW RESOLUTION MODE DENSITIES IN A 96 SEC PERIOD IS USED SINCE THE L-MODE SPECTRA OFTEN ARE SATURATED. COROTATION IS ASSUMED INSIDE L:17.5, AND A CONSTANT VELOCITY COMPONENT OF 200 KM/S INTO THE D CUP IS USED OUTSIDE OF THIS. THESE ARE THE DENSITIES GIVEN IN THE MCNUTT ET AL. (1981) PAPER CORRECTED BY A FACTOR OF 1.209 (.9617) FOR DENSITIES OBTAINED FROM THE SIDE (MAIN) SENSOR. THIS CORRECTION IS DUE TO A BETTER CALCULATION OF THE EFFECTIVE AREA OF THE SENSORS. DATA FORMAT: COLUMNS 1-6 ARE TIME (YEAR, DAY, HOUR, MIN, SEC, MSEC) COLUMN 7 IS THE MOMENT DENSITY IN CM-3. EACH ROW HAS FORMAT (6I4, E12.3). 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 MCNUTT ET AL. (1981) AND A COMPLETE INSTRUMENT DESCRIPTION CAN BE FOUND IN BRIDGE (1977).
|
| PRODUCER_FULL_NAME |
JOHN D. RICHARDSON
|
| SEARCH/ACCESS DATA |
Planetary Plasma Interactions Website
|
|
.png)
.png)
