The cluprobe operator

The cluprobe operator only works on Cluster satellite data.
The Cluster satellites rotates around one time every ~4 second.
The spin axis is almost perpendicular to the orbit plane of the earth.
The Cluster X ephemeris phase_2 shows the direction to the sun , (X = 1,2,3 or 4).
The cluprobe operator indicates when each of the EFW probes points towards the sun.

Mode 1: Show satellite and probes in a new window:

Usage in Calculator:
   p0y = cluprobe(q0,q1)

   q0 is Cluster X ephemeris phase_2
         X = 1,2,3 or 4

   q1 is Cluster X ephemeris position
         X is the same as above.
In this mode a new window (the cluprobe window) appears with a drawing of the satellite and the probes.

Cluprobe
The coordinate system in this window is the Inverted Despun Satellite (IDS) coordinate system.
The z-axis is the negative spin axis. The xy-plane is the satellite spin plane. The direction to the SUN is in the xz-plane.
It is almost parallel to the GSE Coordinate system. (Def of GSE in CSDS User manual Sec 3.13).

The Options in the cluprobe window menubar is used to set the parameters of the cluprobe window.

The Options->Color selection is used to set the color of the window background, EFW probes and FGM booms.

When Options->InScale->on is set the Cluster satellite, the length of the FEW probe wires and FGM booms are drawn in correct scale.
In this case the user must have a very high screen resolution to see the EFW probes.

When Options->Axis->off is set the axis are not plotted.

When Options->Mag->off is set the FGM booms are not plotted.

cluprobe and the ctm time manager:

In order for the cluprobe operator to calculate the phase, the length of the data requested must contain a full 360 deg. spin of the Cluster satellite. In the ctm time manger a useful interval is 10.0 second. However to see the probes rotates the Options->step in the ctm time manger is very useful. Using a step of 0.01 second gives a nice rotation of the probes. In this case the Options->continous in the ctm time manger can be used.
MARK: Do not run Options->continous in ctm for a long time, the ISDAT data base handler dbh is working hard in this mode.

Mode 2: Show probe direction in igr panels:

Usage in Calculator:
   p0y = cluprobe(q0,q1,'e1 e2 e3 e4 m1 m2 m9 dw')

   q0 is "Cluster X ephemeris phase_2"
         X = 1,2,3 or 4
   q1 is Cluster X ephemeris position
         X is the same as above.

   and the options in the third argument are selected from:
      e1  show when efw probe 1 is towards sun, length 1.0   (phase 5/8)
      e2  show when efw probe 2 is towards sun, length 2.0   (phase 1/8)
      e3  show when efw probe 3 is towards sun, length 3.0   (phase 7/8)
      e4  show when efw probe 4 is towards sun, length 4.0   (phase 3/8)

      m1  show when mag (FGM) boom 1 is towards sun, length -1.0   (phase 0/8)
      m2  show when mag boom 2 is towards sun, length -2.0   (phase 4/8)

      m9  show when mag booms are perpendicular towards sun, length -3.0  
                                                              (phase 6/8)
      wd  d=1,2,...,9  width of marker pulse, default is 4    
The first and second arguments in the cluprobe operator have to be the "Cluster X ephemeris phase_2", X = 1, 2, 3 or 4 .
and "Cluster X ephemeris position" (X is the same as above) The third argument is enclosed with ' and ' . A space character between each option.

EXAMPLE:
    p0y = cluprobe(q0,q1,'e3 e4')
    This shows when probe 3 points twoards the sun, length 3.
    This shows when probe 4 points twoards the sun, length 4.

Cluprobe 
This figure shows the result when the p0y = cluprobe(q0,q1,'e3 e4') is used in the igr Calculator. q0 is "Cluster 1 ephemeris phase_2" and q1 is "Cluster 1 ephemeris position". The blue lines with length 3 shows when EFW probe 3 points towards the sun. The blue lines with length 4 shows when EFW probe 4 points towards the sun. LIMITATION: The free() and XtFree() functions sometimes crashes on several data segments. Therefore this operator is set to work on only the first segment. The number of samples in the other segments are set to zero. (This might be solved in the future. Then this operator can be set to work on all segments.)


Updated Aug 05, 2006 by Bjørn Lybekk