Quicklook products are currently produced for six Cluster instruments; CIS
(ions), EFW (spacecraft potential), FGM (magnetic field), PEACE (electrons),
STAFF (electric and magnetic field fluctations) and WHISPER (high frequency
electric field fluctations). A description of all the Cluster instruments is
The quicklook plots are produced at two resolutions, i) Six-hour plots at 1 minute resolution and ii) Whole orbit plots (~57 hours) at 10 minute resolution. Data is normally only presented from one of the four spacecraft (SC3, Samba). This is the spacecraft that has been selected by the Cluster Science Working Team (SWT) as the reference spacecraft and that will be used for the generation of the one-minute validated Summary Parameter data.
In the case of line plots the colour of the line indicates the spacecraft used (Black=SC1:Rumba, Red=SC2:Salsa, Green=SC3:Samba, Blue=SC4:Tango). Science data is taken during about 50% of the orbit and will normally be stored using the on-board solid state recorders. Data is downloaded to ESA's Villafranca del Castillo Satellite Tracking Station (VILSPA). Since a single groundstation is being used to support all four Cluster spacecraft there can be a delay of several days between data acquisition and transmission to the ground.
There are currently three quicklook plot styles defined. The Overview plot provides data from all six instruments showing basic field, particle and wave information. The Fields and Waves concentrates on data from the the FGM, STAFF and WHISPER instruments, while the Particles display shows data from CIS and PEACE. The magnitude of the magnetic field (from FGM) is common to all three plot styles. A thumbnail of the GSE orbit position for the reference spacecraft is also common to all the quicklook plots.
The CIS instrument will provide low energy ion density, velocity and
|EFW provides a measure of the spacecraft potential. The Overview plot show the spacecraft potential from the reference spacecraft and from spacecraft 1 (Rumba). The ASPOC instrument will not be operated on Rumba and in this case the potential can be used as a measure of the plasma density. High density results in low S/C potential, low density in high S/C potential. We therefore plot minus the S/C potential to aid the use of this parameter as a proxy for the plasma density. Comparison of the potentials from Rumba and the reference spacecraft (Samba) provides an indication of the operation ASPOC instrument on Samba and may be useful when looking at the low energy PEACE data.|
|The FGM instrument will provide DC magnetic field information.
Overview: Field magnitude
Fields and Waves:Field magnitude and two direction angles theta, phi (GSE).
Particles: Same as Overview.
|The PEACE instrument will provide low energy electron information.
Overview: Electron spectrogram
Fields and Waves:N/A
Particles: Same as Overview except that the spacecraft potential has been overplotted (dotted < 30eV and solid > 30eV)
|The STAFF instrument will provide information on fluctuations in the
magnetic and electric fields.
Overview: Bx Spectrogram from the STAFF Spectral Analyser
Fields and Waves:Bx Spectrogram from both the Spectral Analyser and direct search coil measurements. Also Ez from the Spectral Analyser.
|The WHISPER instrument will provide information on the high frequency
Electric field fluctuations .
Overview:Electric field spectrogram
Fields and Waves:Same as overview.
Below the time axis of each plot are displayed a set of horizontal lines. The thickness of these lines indicate the telemetry collection mode on each of the four spacecraft. A thin line indicates that a spacecraft was operating in normal mode, a think line denotes the enhanced burst mode and no line means that the spacecraft was not in a science collection mode. The lines are colour coded according to the spacecraft (from top to bottom; Black=SC1:Rumba, Red=SC2:Salsa, Green=SC3:Samba, Blue=SC4:Tango). This information is only added once the Summary Parameter Auxiliary files become available and so will not be displayed on the most recent data.
Information on the position of the reference spacecraft is taken from the JSOC catalogue files (please visit the JSOC web site for more information). A sub-set of these data are plotted including the location, L-shell and Magnetic Local Time of the reference spacecraft, and some of the four spacecraft configuration parameters (elongation, planarity and size). The full data set can be accessed from the national data centres. Field tracing using T96 (s/w pressure 4, DST -10, IMF BY -2, BZ 5.0) has been used to calculate the approximate location of the magnetic footprint when the spacecraft are inside the magnetosphere.
For these plots the latest (>|) control on the interface will take you to the plot corresponding to the latest quicklook plot. There will usually be predicted position plots beyond this, and these can be accessed either using the forward (>) control or by setting the date.
|The following JSOC predicted scientific
events are also marked.
PE - Perigee
AP - Apogee
QL - Auroral Oval
NT/ST - Tail Xgse < -10 Re
NS - Neutral Sheet Crossing
MP - Magnetopause
BS - Bow Shock
|To simplify selection of particular orbits, a page based on the JSOC Master Science Plan, Bryant plots is provided. Clicking inside the plot will display the corresponing quicklook whole orbit plot. A separate browser window (target name "Cluster_Quicklook") will be used allowing quick navigation of of the MSP.|
Each of the data plots has a small thumbnail schematic of the orbit in GSE. In the case of the whole orbit plots, clicking on the thumbnail will take you to a full size view of the GSE orbit and of the constellation configuration. Constellations are plotted every 9.5 hours and the phasing is shifted slightly so that over a number of plots the evolution round the orbit can be seen. The orbit is coloured according to the reference spacecraft (green= SC3 in the example). The other spacecraft are plotted relative to the reference spacecraft and expanded by a factor of ~ 10 to 35 to allow them to be viewed on the orbit plot. The first constellation after perigee has the reference spacecraft marked with a diamond.