Three_C

Using Planner

  1. Turn on the computer the monitor, and the printer. Power for the computer and the monitor is routed through a surge protector which also controls the WWV clock. Since the clock needs to be on constantly, do not turn off the power switch on the surge protector.
    The software makes assumptions about the location of the devices it controls. These assumptions define the HOME position and are: the telescope is 15 above the due South point, the filter wheel is on Clear, the dome is on tooth 298 (labeled along the track - approximately due East), and the offset stages are in the center of their respective ranges.

  2. Turn on the Main Power and Photometer switches on the rack.
    The Main Power switch controls power to the Superior Equipment in the rack and the Photometer switch controls power to the photometer and its stepper motors.

  3. Make sure the dome slit is open and the slit power cord is disconnected.
    The Ash Dome has a segmented slit. When opening, decide whether the lower segment should be up or down and set the hook appropriately using the attached chain. When the slit is fully raised, unplug the power cord and wrap it around the power box. We have spent several unpleasant nights rewiring the plug after it was ripped out of the wall socket.

  4. Type planner
    The first screen to appear asks for some basic information.

    Enter barometric pressure (inches) :30.00
    Enter mean temperature (deg F) :50.0
    Star Catalog Name :
    Altitude of rise/set (30) :30
    Press ENTER to accept, ESC to abort

  5. If ENTER is pressed on a line containing a default value, that value will be used. The procedure for computing the automatic moves requires the temperature and pressure in order to compute the refraction correction. The catalog name must be created in advance, using any common full screen editor. See the section below on catalog generation. Include the extension in the catalog name (e.g., wcat1.dat). The altitude of rise/set sets a limit for considering an object to be available for observation. Only objects that meet the condition of having altitudes greater than this limit will be available for selection. The built-in constraints on the telescope, however, will not allow it to move to an altitude less than 20 under automatic control.

    This is a dialog box, so that if errors in entry are made before leaving this screen, simply use the cursor keys to return to the proper line and enter the correct data.

    When ENTER is pressed at the end of this screen, planner will display the following screen

    Astronomical Data - SFASU Observatory
    Jul 1 1996 Latitude = 31.75
    Time Zone CDT Longitude = 6.31
    JD at 24H UT50266.5000
    JD at 22:14 CDT50265.9041
    ST at 24H UT12:22
    ST at 22:14 CDT22:02
    Sunset20:28
    Evening Twilight22:07
    Dawn Twilight04:39
    Sunrise06:18
    Length of day14:10
    Moonrise20.58
    Moonset06:54

    Note: Moonrise/set are listed for the 24 hour period given above.Rise, set, and twilight times are CDT.

  6. The information presented here is necessary for the correct operation of the three_c program and is listed here for the information of the user. Program execution is paused at the bottom of this screen. If you would like to print this information, press PrintScreen. When you are ready to continue press Enter. The calendar information just computed is then stored in a file called nitefile.dat. Along with the calendar information displayed above, planner computes the night coordinates of the catalog stars. It applies corrections for precession, aberration, and nutation, determines which of the catalog stars will be above the critical altitude from the end of evening twilight to the beginning of dawn twilight, eliminates objects from the list which are within 15 of the moon, and sorts the remaining objects in terms of their set times. The updated coordinates of the sorted and culled list of objects is written to a file called starfile.dat. Control is then returned to MSDOS.