The Uvplot Parameters File

The uvplot.par file contains parameters which govern the execution of the program. The contents and order in which entries must appear in this File are shown in Table 4, which reflects the values in the file as originally supplied on the distribution disk. Some explanatory notes about the contents of the uvplot.par file are given below.

  
Table 4: Uvplot.par file used in uvplot and allsky

Lines 6-8 contain the pointing vectors of the three star sensors of the attitude control system (OZD). These vectors are input as , , coordinates in the satellite frame of reference (see Figure 1). The following line contains the minimum angles in degrees between these vectors and a vector pointing from the satellite to the sun, moon, and earth, respectively. Following is the vector in the satellite reference frame for the axis of the high gain antenna.

The maximum - range to be displayed in the coverage plots may be specified in line 11, and should be entered in wavelengths.

The nup value is the minimum number of telescopes (including the spacecraft) that must be able to observe the source before - tracks will be displayed. The minimum value for this parameter is 2.

The following line provides uvplot with the first 4 characters of the rotation angle file name to be constructed if the switch to create uvplot data file is set to 10 or 11. The remainder of the file name is created from the truncated right ascension and declination of the source being observed. Using the 4 characters in this file for a source at ra = 22.4 hours and dec = 50.9 degrees, the file name constructed would be long2250.par.

In the three lines containing toggles for colour uv tracks, pointing restrictions and S/N threshold toggle,0 represents `on', and 1 `off'.

The double parameter line following this contain the switches which govern the writing of the - and rotation data to disk. Both switches can be set to either 1 or 0. The contents of this data file are documented in detail later in this manual (see Section 5.8.1). The following combinations produce these results:

• 0 0: do not create a uvplot.dat file. Note that in this case a SNR plot may be generated by uvplot only if there is already a uvplot.dat file on disk, created by an earlier run of uvplot.

• 1 0: create a uvplot.dat file containing only the satellite-earth baseline () coordinates.

• 1 1: create a uvplot.dat file containing both the satellite-earth and earth-earth baseline information.

• 0 1: create a uvplot.dat file containing only earth-earth baseline information.

Line 18 contains the scale for the SNR plots. If this value is set to 0, then the program will enable auto-scaling of the SNR data. If other then 0, then the value specified, which must be an integer, will be the maximum value appearing on the SNR plots; any SNR values greater then this will be clipped.

The next line sets the signal to noise threshold at which to carry out any desired actions.

The source name line may have a maximum of 12 characters.

The next line in uvplot.par is the coherence time in minutes of the observation, which is set to the integration time for the purpose of calculating the noise on each baseline. If is the time interval between solutions (which should be larger than the coherence time ), then data are obtained during a time interval of every minutes.

The following line is for choosing to make polarization - plots.

The second last line allows the user to choose what fraction of the earth-earth baseline points to plot. In the table use has set a value of 4 which means to plot only 1 out of every 4 points. If a value of 0 is given then no earth-earth baselines are plotted and only the earth-satellite baselines will show up. This feature is used primarily to speed up the display of uvplots in /bf uvplot and /bf allsky plus to make any Postscript output files smaller since the bulk of the file contains earth-earth points which can greatly increase the size of a postscript file.

The last line is to choose which satellite to use in making uvplots.