Simplified User Mode (SUM) for the 37-m Telescope


This mode is available for users who do not need the advanced capabilities of the complete Umbrella program. It provides the most often used modes in a simple click and go fashion.

A description of the capabilities is given below. Commands to be typed at the X-window prompt are given in red. The descriptions are for the particular properties of this mode. For more detailed descriptions of the individual commands go to the Umbrella manual.

The program is started from an X-window on Fourier (to access fourier and set up X-windows on your Windows machine check the Haystack web site at http://web.haystack.mit.edu/obs/haystack/user_guide).

At the fourier prompt type

user@fourier[4]% KS
Several windows will pop up, two of which will eventually be hidden by other windows. These hidden windows are not necessary to the operation of the SUM mode. The final screen will look like this:

SUM screen

The screen will contain –
  1. The Xterm window (Xterm fourier.haystack.edu) where the original command was typed. This provides an interface to the Linux system and will be used for drift plot displays etc.

  2. An automatically updating (about every 10 seconds) image of the antenna in the top left-hand corner

  3. The traffic light system (called WatchThis), which shows the status of the important systems at a glance. Clicking on any one of the lights will provide more, mainly diagnostic, information.

  4. A status window (K Status) that provides information about the telescope position, active command and system temperature. This is useful in determining if the chosen commands that are being or have been executed.

  5. A command window (K…). Three main operations (Source, Frequency, and Observation) are allowed from here and they can be selected from pull-down menus.

  6. The upper plot window (tektronix (Tek)) shows the results of continuum (Discrete Source Scans - DSS) scans. The bottom plot is of signal strength (in Kelvins on the vertical axis) versus azimuth offset (in degrees on the horizontal axis) and the top plot is signal strength versus elevation offset. The center of each plot is the nominal pointing center from the input pointing model.

  7. The lower plot window (another Tektronix (Tek)) shows the results of spectral integrations. The bottom curves show the shape of the bandpass and the top plots are of the spectra – signal strength (in Kelvins on the vertical) versus Doppler velocity (in km/s on the horizontal). In the case of the K-band (1.3 cm) receiver only the left plot will be updated since there is only one channel. The right hand plot will show the last Q-band (7mm) spectrum and associated bandpass. In the case of the Q-band (7mm) receiver both plots (two polarizations) will be updated.


Source:

This button allows the user to choose from a catalog of sources. The planet and Sun and Moon positions are determined from an ephemeris. The positions of the other sources are defined in the schedule file for this program. These source positions also have epochs and velocities associated with them, and are listed below.

Source name Right Ascension Declination Epoch Velocity (Km/s) Bandwidth (MHz) Comments
Crab Nebula 05 34 31.44 22 00 52 2000 0 160 Supernova remnant
Cygnus A 19 59 28.36 40 44 02 2000 0 160 Radio Jet
NGC7538 23 11 36.6 61 11 48 1950 -58.0 160 Molecular cloud
Mira 02 16 49.4 -03 12 13 1950 47.0 17.8 Evolved Star
IK Tau 03 50 43.6 11 15 32 1950 34.4 17.8 Evolved Star
Orion 05 32 46.6 -05 24 30 1950 -3.7 17.8 Molecular Cloud
RLeo 09 44 52.2 11 39 42 1950 -2.5 17.8 Evolved Star
VyCMA 07 20 54.6 -25 40 12 1950 23.5 17.8 Evolved Star
ScrB 15 19 21.5 31 32 47 1950 0.5 17.8 Evolved Star
W3OH 02 23 17.8 61 38 58 1950 -48.0 5.93 HII region
KLIrc2 05 32 47.0 -05 24 23 1950 8.7 5.93 Young Star
W49 19 07 49.8 09 01 17 1950 10.0 5.93 HII region
W75N 20 36 50.5 42 27 01 1950 13.15 5.93 HII region
GGD37 22 54 19.2 61 45 44 1950 -8.8 5.93 HII region


The sources that have a wavelength associated with the name have their velocities setup for the narrow maser emission. Other sources may be added to this list.

The "Park" position stows the antenna at an azimuth of 327° and an elevation of 45°.

SUM Screen

Frequency:

Several frequencies (all in GHz) are provided here. Except for the "generic" ones, the frequencies all correspond to rotational transitions in molecules. The available frequencies are given below. In the panel the frequencies are in GHz and the wavelengths of the corresponding bands are also indicated.

  1. 21.0 – a generic frequency for continuum observations
  2. 22.235080 – Water (H2O) – 6(1,6) → 5(2,3)
  3. 23.696494 – Ammonia NH3(1,1)
  4. 23.722632 – Ammonia NH3(2,2)
  5. 41.0 – a generic frequency for continuum observations
  6. 43.122027 – Silicon Monoxide (SiO) - 1→ 0, v=1
  7. 44.069490– Methanol (CH3OH) – 7(0) → 6(1) A+


SUM Screen

Observation:

After the user has selected a source and a frequency, they can select one of several often-used modes of observation. It is important to note that the observation selected has to match the selected source and wavelength band (7mm or 13mm). When the "observation" button is clicked on, these modes are shown. They are as follows:
  1. DSS – Wideband – 7mm: This mode is for the discrete source scan on a continuum source at 7mm. Choosing this mode will enable a bandwidth of 160 MHz, turn on the beamswitcher, do a calibration, and run the DSS command. The program will automatically plot the results of the scan in the upper right plot window and transfer the DSS derived position offsets into the telescope system, provided the DSS is judged to be good. The DSS observations will take 3-4 minutes.

  2. DSS – Line – 7mm: This mode will perform a DSS on a strong SiO maser line source. The bandwidth is set to be very narrow so that the strong line mimics a continuum source in the band. As in the first mode, the offsets are automatically transferred.

  3. DSS – Wideband – 13mm: This mode is for the discrete source scan on a continuum source at 13 mm. Choosing this mode will enable a bandwidth of 160 MHz, turn off the beamswitcher, do a calibration, and run the DSS command. The program will also automatically transfer the DSS derived position offsets into the telescope system.

  4. DSS – Line – 13mm: This mode will perform a DSS on a strong water maser line source. The bandwidth is set to be very narrow so that the strong line mimics a continuum source in the band. As in the first mode, the offsets are automatically transferred.

  5. DriftMap-7mm: This command will perform a drift map of a source at 7mm (36-43 GHz). The user first needs to select a 7mm frequency from the frequency list. The drift parameters are pre-selected to make a map of (600Cos* x 360) arcseconds around the center position, where * is the declination of the source. The map should take about 15-20 minutes. The results of the drift map are not automatically displayed. See section below on plotting the results of a drift map.

  6. DriftMap-13mm: This command will perform a drift map of a source at 13mm (21-24 GHz). The user first needs to select a 13mm frequency from the frequency list. The drift parameters are pre-selected to make a map of about (600Cos* x 360) arcseconds around the center position, where * is the declination of the source. The map should take about 15-20 minutes. The results of the drift map are not automatically displayed. See section below on plotting the results of a drift map.

  7. Quick-Look-7mm-Spectrum: This command will make a 30 second beamswitched spectrum on a pre-selected source at a pre-selected frequency. The bandwidth is set to 17.8 MHz.

  8. Quick-Look-13mm-Spectrum: This command will make a 1 minute position switched spectrum on a pre-selected source at a pre-selected frequency. The bandwidth is set to 17.8 MHz.

  9. 13-mm-Switched-Spectrum: This command will make a 30 second frequency switched spectrum on a pre-selected source at a pre-selected frequency in the 21-24 GHz band (13mm). The bandwidth is set to 17.8 MHz. The frequency offsets are set to ¼ of the bandwidth.

  10. Exit: This command will shutdown the SUM mode software and exit all the windows.

  11. Abort: This command will allow the user to abort the active command.


SUM Screen

Example window with an active DSS command running. Notice that the OnSource button in the Status window is green and the active command says "DSS". The RA and Dec and epoch fields are filled with the source coordinates.

SUM Screen

Plotting the results of a drift map

The results of a drift map are not automatically displayed. In order to see the map, in the Xterm window, type:
user@fourier% DriftMap
This will (after a few seconds) plot your drift scan as a color map in Right Ascension and Declination coordinates (labeled in arcseconds). The map color levels can be manipulated by moving the cursor to any part of the map and "clicking" the mouse (left or right buttons will work). The plot levels should be correct by default

When you have the desired color levels, move the cursor to any spot within the PGPlot window and type:
user@fourier% q
This will freeze the plot levels. The q command also creates a postscript file pgplot.ps. It is recommended that you rename the pgplot.ps file before you run another driftscan and map plot as the next plot will write over the pgplot.ps file.


Appendix for Experienced Users

The full Umbrella is running behind the scenes in K mode.  The "WatchThis" traffic lights and their additional frames are described in WatchThis and in Frequently Asked Questions.

The two active icons along the right edge of the screen (perhaps under the DSS plot) are "Xterm Log" and "Xterm Umbrla" as usual but with an unreadable font.  These are xterms and can be expanded to be readable as follows:  With the cursor inside an active icon, <Ctrl> right click and hold the click while pulling the cursor down the list of fonts that appears.  (This is difficult because the font is unreadable.)  When you release the mouse click, the corresponding font will replace the unreadable font and the xterm will expand to show 80 columns by 24 lines as usual.  Repeat if necessary.  You may need to use the mouse to slide the xterm left.

The "Abort" command sends an INTERRUPT (<Ctrl> C equivalent) to Umbrella.  Use repeatedly if necessary.

Two additional scripts are intended to help in K mode:
dssamp

shows the results of the last DSS if GOOD, perhaps to be used to calculate efficiencies or fluxes.


You can't type into "Xterm Umbrla" in K mode, but the cheat script allows a command to be sent to Umbrella behind the back of K mode:

cheat <arbitrary string to be sent to Umbrella>

Cheat can be used repeatedly.  This allows an experienced user to seriously mess things up:  Caveat usor.