| URAP |
A URAP Summary Plot is a plot of one day of Ulysses STO Unified Radio and Plasma (URAP) experiment data. The URAP experiment consists of five instruments: Radio Astronomy Receiver (RAR); Plasma Frequency Receiver (PFR); Wave Form Analyzer (WFA); Fast Envelope Sampler (FES); and Sounder (SND). The Summary Plot consists of six plot panels. Data is plotted in the form of dynamic spectra (3 dimensional plots of wave amplitude versus frequency and time, with the degree of darkness proportional to the wave intensity. Frequency is plotted along the vertical axis, and time is along the horizontal axis. A description of each plot panel is given in Section II.
The data is on the plot is stretched (assigned a grey shade) between minimum and maximum data values, the maximum being the minimum plus dynamic range designated for a receiver. The specified dynamic ranges are shown at the right side of the plot, under the heading "Dyn. Range". A linear interpolation is done between minimum and maximum values to determine the degree of darkness of the plotted data point. Data at or below the minimum is plotted as white, and data at or above the maximum value is shown as black. Pixels having sixteen different grey shades have been defined, although the eye can distinguish only about 8 shades.
The hardcopy plot consists of six panels, the first four of which are plotted with time along the horizontal axis. For these plots the time increment is 128 seconds, which means that up to 675 possible times are plotted along the horizontal axis. For instruments with a higher time resolution than this, the maximum data value occurring during a 128 second interval is plotted. Frequency is plotted along the vertical axis. Frequency labels such as 100K refer to 100 KHz; otherwise the labels refer to Hz. Dynamic ranges shown at the right of the panels are in telemetry units, except for the WFA, which are in logarithm of decompacted FFT output. The panels are described in order from top to bottom.
The bottom two side-by-side panels (to the right of the plot label) show data for each observed FES event for high band and low band detectors. For each event, shown by a straight horizontal line, 1024 data points are taken. On the plot, however, only the maximum value of 4 contiguous points is displayed. Up to 56 individual events may be plotted. The events are plotted from bottom to top of panel in order of their occurence. The vertical scale is time of event in hours of the day. Each event shown represents the most intense FES event observed during 49 formats (a format is 32 sec at 1024 bps). These panels are in the form of dynamic spectra; therefore the degree of darkness is proportional to the intensity of data observed during event.
The FES lo and hi band plots show two vertical lines at the beginning of each plot. These indicate the instrument antenna and filter status. For the hi band receiver the Ex antenna is flagged by a black point, and the Ez antenna by a light point. The 6-60 kHz filter is shown by black, the 2-20 kHz band is designated by a light point and all bands with an upper limit of 6 kHz or lower has no point. For the lo receiver a black point indicates Ex, a light point Ez, and no point the B antenna. For the filter band, a black point indicates 2-10 Khz, a light point .6-6 kHz, and no point indicates the upper frequency limit is lower than 2 kHz. When the FES receiver is attached to the B antenna, the band is always 0.01-1 kHz.
The option exists for plotting electron plasma frequency fpe, ion plasma frequency fpi and electron gyrofrequency fce as lines on the dynamic spectra. The fpe data is plotted on the PFR plot, fpi is plotted on the EWFA panel, and fce is shown on the BWFA panel. These data are obtained from Ulysses files of plasma (BAM) and magnetometer (HED) data.
Various plot labels are printed in the lower left-hand corner of the Summary Plot. The first 3 lines give date of the plotted data, version number of the Summary Plot program, and date the plot was generated. The next 2 lines designate the RAR hi and lo receiver modes at the beginning and end of the plotted time interval. The modes are M (measure mode), L (linear sweep), and F (freeze mode). For measure mode, the list number is given after the "#" sign. For freeze mode, the frequency number follows the "#" sign. For the low receiver in measure mode, "F" designates full list, "E" indicates first half of list, and "O" implies the second half of the list is used.
The next line indicates RAR background type and offset. Designation for the RAR background determination is as follows: Background type "0" indicates offset values (computed minus standard background values) and dynamic ranges may be specified for the RAR receiver. Background type "1" indicates that for each frequency a background is computed from the data for that day, and a histogram of data minus background for all frequencies is used to automatically set the offset and dynamic range for each RAR receiver. The offset and range depend on the percentage of white and black pixels chosen by the user. The offsets (either chosen or computed) are shown after the "/". The 3 offsets shown correspond to offsets for the RAR X hi, X lo, and Z hi, respectively.
The next line shows the minimum and maximum data values in telemetry units for the RAR lo X data for the day.
In the next 3 lines, distances and angles are given as determined using various locations, namely, Ulysses (U), Sun (S), Jupiter (J), and Earth (E).
The last 2 lines give the longitude and latitude of the spacecraft in either heliographic coordinates (_H) or sun-centered coordinates (_E), as determined from the SEDR database.
The backgrounds (i.e. minimum values for stretch) and dynamic ranges (maximum minus minimum values) are determined as follows:
Backgrounds are computed from the data and a histogram of data minus background (E-B) for the receiver is determined. This is done separately for each RAR receiver (RAR X hi, RAR X lo, RAR Z hi) as well as for the non-RAR receivers (PFR, WFA hi, WFA lo, B WFA hi and B WFA lo). The receiver background and range is defined by this histogram; i.e. the background is defined as some minimum E-B value, and the range is defined as some upper E-B limit minus the minimum E_B value. A percentage of white and black pixels is specified, typically 4% white and 4% black, in effect setting the minumum and maximum E-B values for the plot. The E-B data is therefore "stretched" between these limits, i.e. a grey level is assigned to each E-B value which is proportional to the data value between minumum and maximum limits. The dynamic range label reflects the difference between minimum and maximum E-B values.
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Updated 2005-10-17