Data Set Summary ================ Data Set ID: N/A Instrument: URAP Instrument P.I.: Robert J. MacDowall Data Supplier: Roger Hess Data sampling rate: N/A Data Set Start time: 1992-01-01T00:00:00.000Z Data Set Stop time: 1992-04-30T23:59:59.999Z Naming convention ----------------- Plot files in this data set are named according to the convention: Pyymmdd.PS where yy = the last two digits of the year ('92' for 1992) mm = month of the year covered in the plot dd = the day of month covered in the plot Record format ------------- These plot files are stored in PostScript format. Data column descriptions ------------------------ N/A Missing data flag value ----------------------- N/A Data Description ================ GUIDE TO THE ARCHIVING OF ULYSSES RADIO AND PLASMA WAVE DATA Roger Hess, Robert MacDowall, Denise Lengyel-Frey March 15, 1995 Contents 1 Introduction 3 2 Delivery Schedule 3 4 World Wide Web Access to URAP Data 7 APPENDICES 8 B URAP SUMMARY PLOT DESCRIPTION 17 B.1 Overview 17 B.2 Plot Description 18 B.2.1 Plot panel descriptions 18 B.2.2 Overplotting plasma frequency, gyrofrequency 20 B.2.3 Plot Labels 20 B.3 Computed Background and Dynamic Range Determination 21 1 Introduction The Unified Radio and Plasma wave instrument (URAP) is designed to detect both remotely-generated electromagnetic waves and in-situ plasma waves. The former are radio waves arising from electron beams in the solar wind (type II and type III radio bursts), planetary radio emissions (from Jupiter, the Earth, etc.), and a cosmic background from the local galactic medium. The in-situ waves include thermal plasma fluctuations, electron plasma oscillations (Langmuir waves), ion-acoustic waves, and whistler-mode waves. Wave electric fields from less than 1 Hz to 940 kHz and magnetic fields from less than 1 Hz to 448 Hz can be measured. An extensive description of the five instruments that make up the URAP investigation can be found in [STONEETAL1992A]. Details relevant to the data archive are contained below. The Astron. Astrophys. Suppl. Ser. issue also contains other articles describing the Ulysses spacecraft as a whole and the other Ulysses instruments. Ulysses is spun for stability with a period of approximately 12 sec. The Z axis of the spacecraft is defined as being along the spin axis. The X and Y axes are perpendicular to the spin axis. URAP measures electric field by means of two antennas. One is a dipole formed by two 35 meter long wires along the +/- X axes and the other is a 7.5 meter long monopole that is on the Z axis Because of the longer length of the X antenna compared to the Z antenna, it is much more sensitive and has a much lower background signal level. For these reasons, only the X antenna data are provided in the UDS data files. Magnetic fields are measured by means of a two axis sensor aligned along the spacecraft Y and Z axes. 2 Delivery Schedule The URAP team will provide the archival data products to the Ulysses Data System no later than 2 months after GSFC has received the raw data. These data will be provided to the NSSDC no later than 1 year after GSFC has received the raw data. 3 Description of the Unified Radio and Plasma Wave Instrument The Unified Radio and Plasma Wave instrument on Ulysses is divided into several sub-instruments. Data from three of these sub-instruments, the Radio Astronomy Receiver, the Plasma Frequency Receiver, and the Wave Form Analyzer, are represented in the URAP archival data. 4 World Wide Web Access to URAP Data Some of the URAP data are being made available over the World Wide Web (WWW). By this means, the data are made convenient and quick to use by a much larger audience, including anyone with access to the Internet. The URAP home page on the WWW provides more information for those interested. The home page makes available color dynamic spectra of the RAR data and information on the location of Ulysses during the mission. Educational material and a bibliography of papers describing Ulysses and URAP are also provided. The home page also gives links to other WWW sites of interest including NASA, Goddard Space Flight Center, the Jet Propulsion Laboratory and the European Space Agency, as well as other investigators using the Ulysses instruments and data. The Universal Resource Locater for the URAP home page is http://urap.gsfc.nasa.gov/www.urap_homepage.html APPENDICES A UDS data files Eight files are provided that conform to the UDS conventions regarding the naming of files and the format of the data. The eight files are divided into 4 pairs of files with each pair consisting of a file containing data averaged over a 10 minute period and a file containing the maximum data value during the same 10 minute period. The 4 pairs of file contain data for the RAR, the PFR, WFA - magnetic field, and WFA - magnetic field. B URAP SUMMARY PLOT DESCRIPTION Version 10 March 1995 B.1 Overview A URAP Summary Plot is a plot of one day of Ulysses 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 are plotted in the form of dynamic spectra (3 dimensional plots of wave intensity versus frequency and time, with the degree of darkness proportional to the wave intensity. Frequency is plotted along the vertical axis, and time along the horizontal axis. A description of each plot panel is given in Section II. Most of the data are 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 are plotted as white, and data at or above the maximum value are shown as black. The pixel-font uses a 4x4 dot pattern to represent 16 shades of gray. B.2 Plot Description B.2.1 Plot panel descriptions The 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 675 time steps are represented along the horizontal axis, corresponding to 24 hours of data. For data 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 ranges, which are in logarithm of floating point DPU-FFT output. The panels are described in order from top to bottom. Panel 1 This is a dynamic spectrum of RAR X antenna electric field data. The full set of 12 high receiver frequencies and 64 low receiver frequencies is plotted, with interpolation done for any missing frequencies (extrapolation is not done). The high receiver frequencies have a logarithmic spacing between approximately 50 KHz and 1 MHz. The low receiver frequencies are spaced linearly in frequency between 1.25 and 48.5 KHz. Panel 2 This panel is a dynamic spectrum of electric field data from RAR, PFR and WFA instruments. The 12 frequencies of the RAR high receiver Z antenna data are plotted. A gap separates RAR and PFR data. The PFR data is the peak data from the X antenna. Thirty-two PFR frequencies are plotted, ranging from 0.5 to 35 KHz. When the PFR is in fixed tune mode, there are 32 times as many PFR samples at a single frequency. They are spread across the 32 frequencies, to permit a better representation of the single frequency data. Twenty-four WFA frequencies from the X electric field antenna are plotted at the bottom of the panel. The low receiver frequencies range between about 0.1 to 5 Hz; the high receiver frequencies range from 9 to 448 Hz. The frequencies are approximately logarithmically spaced. The data plotted are average data from the WFA instrument. Panel 3 WFA magnetic field data are plotted here. The high receiver data (upper 12 frequencies) are always from the Y search coil. The low receiver (lower 12 frequencies) will be either Y or Z search coil data, depending on which search coil was being sampled (indicated in panel 4). Frequencies and units are as for the WFA Ex data. Panel 4 This panel indicates various instrument statuses. A dark line indicates an "on" condition, and a light line indicates "off". Six status flags are shown. These are: a) RAR SUM: The flag indicates whether the RAR is in summation (X+Z) mode. A dark line indicates summation is on. There are a pair of lines for this flag. The top line of the pair indicates RAR high receiver summation, and the second line indicates low RAR receiver summation. b) RAR POLAR: This flag indicates RAR polarization mode on or off. Again, the first of the two polarization lines is for the high receiver and the next is for the low receiver. c) PFR Fast: a dark line indicates that the PFR is in fast-scan mode; a light line indicates that the mode is slow-scan; no line indicates fixed-tune (single-frequency) mode. The fixed tune frequency is shown during the fixed tune interval. Note that the PFR causes a mode (and bit rate) dependent interference in the WFA data. d) Greater than 10 Hz Ez: This flag indicates that the WFA high receiver data is from the Ez antenna (dark) or, alternatively, from the WFA Bz antenna (light). Note that neither of these types of data is plotted on the Summary Plot. (Only Ex data is plotted for the high band EWFA; only By data is plotted for the high band BWFA.) e) Less than 10 Hz By: This indicates whether the magnetic data in the low receiver is from the By (dark) or Bz (light) antenna. This flag does correspond to the data plotted for the B lo receiver. f) 1024 bps: A dark line indicates 1024 bps data. A light line indicates 512 bps. A blank corresponds to a bit rate lower than 512 bps or a data gap. Panels 5,6 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 occurrence. 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 low and hi band plots show two vertical lines at the beginning of each plot. These indicate the instrument antenna and filter status. For the FES high band 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 filter is designated by a light point and all filters with an upper limit of 6 kHz or lower are designated by a blank. For the low receiver antenna, a black point indicates Ex, a light point, Ez, and no point, the B search coils. For the low band filter, 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. B.2.2 Overplotting plasma frequency, gyrofrequency 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 (SWOOPS) and magnetometer (MAG) data, provided by the respective instrument teams. B.2.3 Plot Labels 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 high and low 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 high, X low, and Z high, respectively. The next line shows the minimum and maximum data values in telemetry units for the RAR low 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 ecliptic coordinates (_E), as determined from the SEDR database. B.3 Computed Background and Dynamic Range Determination Backgrounds may be computed from the data. This is done separately for each RAR receiver (RAR X high, RAR X low, RAR Z high) as well as for the non-RAR receivers (PFR, WFA high, WFA low, B WFA high and B WFA low). The goal is to achieve a full utilization of the gray scale. To accomplish this, a percentage of white and black pixels is specified, typically 4% white and 4% black. Histograms of the data values are computed for each panel. The background and range are defined by these histograms; i.e. they are calculated to provide the percentages of black and white pixels specified.