USER NAME (3 characters long):                 PRH
DEFAULTS:
  Number of images of each target:             3
  Type of image sequence (suc,mot):            mot
  Image insertion method (opt,asap,alap,mix):  mix
  Minimum altitude (deg):                      30
  Maximum |hour angle| (min):                  500.
  Moon avoidance radius at full moon (deg):    40.
  Max. random offset for target positions ("): 10.
  Frame mode (dark, light):                    light
  Resolution (high, medium, low):              high
  Frame size (full, center):                   full
  Filter:                                      clear
  Image compression method (none,FITS,zip):    FITS
  Exposure times (sec):
     1.
     2.
     4.
    10.
    20.
    30.
    40.
    60.

User profiles are usually saved to directory TAO\schedule. This sample user profile (TAO\schedule\PRH.txt) may be used as a template for creating your own user profiles. If you use more than one telescope, each one may have its own set of user profiles.

If a user runs two different observing programs on the same telescope, it may be convenient to create two different user profiles, with different user names, each profile containing the default preferences for one of the observing programs.

The various options which may be specified in a user's profile are described below:

• User name. This is a 3-character upper-case string which serves to identify the user.

• Number of images of each target. Observers who do minor planet/comet searches or astrometric follow-up often take 3 or 4 images of each target in order to clearly detect their motion. Photometric observers may take long time series consisting of tens of exposures. Supernova searchers usually take one exposure of each galaxy per night. The default number of images may be overriden by specifying the number of images in individual observation requests.

• Type of image sequence. This option specifies how the time interval between successive exposures of a given target (belonging to the same observation request) is determined by program Schedule. When this option is set to suc (short for successive), each exposure in the requested sequence is taken immediately after the end of the download of the preceding exposure (in practice, a short interval may exist between the end of the download of one exposure and the start of the next exposure due to the possible need to move the telescope to compensate for the target's motion, and to wait for the mechanical vibrations to settle down). Observers who do minor planet/comet astrometric follow-up will often set this option to mot (short for motion), which means that the time interval between successive exposures of a given target is determined by the target's rate of motion. This time interval will be inversely proportional to the target's rate of motion, so that all targets will move about the same user-specified number of pixels between successive exposures (this constant displacement is very convenient for either automated moving object detection or visual blinking). The default type of image sequence may be overriden by specifying the type of image sequence in individual observation requests. The user may also specify a desired time interval between the exposures of a given target; this time interval is specified in the individual observing requests, not in the user profile.

• Image insertion method. When processing a given observation request, Schedule tries to choose the "best" times to take the requested exposures. Here "best" has different meanings depending on the values of this option:
  • opt means that the scheduler chooses the observation times so as to maximize the altitude at which the images are taken.
  • asap means that the scheduler chooses the earliest available observation times. This is useful when bad weather is expected after some time during the night and you wish to observe certain targets as soon as possible, although possibly not at the highest possible altitudes.
  • alap means that the scheduler chooses the latest available observation times. This is useful when the weather is expected to improve after some time during the night and you wish to observe certain targets as late as possible, although possibly not at the highest possible altitudes.
  • mix means that the scheduler chooses the observation times so as to achieve a trade-off between maximum altitude and minimum slew time in moving between the requested target and the next target. The relative importance of slew time minimization in this trade-off may be specified by the user in the scheduler configuration file.
  The default image insertion method may be overriden by specifying the image insertion method in individual observation requests.

• Minimum altitude. This is a default minimum altitude value (expressed in degrees), which serves to ensure that no observations are scheduled to take place at an excessively low altitude. The default minimum altitude may be overriden by specifying the minimum altitude in individual observation requests. The scheduler also uses the model of the local horizon line to prevent observations through horizon obstructions. No observations are ever scheduled to take place below the model horizon line, regardless of the minimum altitude values specified by the users in their observation requests and user profiles.

• Maximum |hour angle|. This is a default maximum absolute value of the hour angle (expressed in minutes of time), which serves to ensure that no observations are scheduled to take place too far from the meridian. The default maximum |hour angle| may be overriden by specifying the maximum |hour angle| in individual observation requests. The scheduler also imposes maximum and minimum |hour angle| limits, which apply to all users regardless of the maximum |hour angle| specified in their user profiles or observation requests. These absolute limits represent the telescope safety slew limits, which should not be violated by the individual users.

• Moon avoidance radius at full moon. This parameter specifies the default value of a variable avoidance radius (expressed in degrees) around the moon, which serves to prevent observations too close to the moon. The radius specified in this parameter is the avoidance radius around the full moon. For other moon phases, the avoidance radius is scaled by a factor (1 - cos d)/2, where d is the angular separation between the sun and the moon in the sky. Therefore, the avoidance radius drops to one half its full moon value when the moon is in quadrature (d = 90 deg), and to zero at new moon (d = 0). An observation request will not be carried out when the distance between the target and the moon is smaller than the scaled avoidance radius for the moon phase at the date of observation. The avoidance radius only takes effect when the moon is at an altitude greater than -5 deg. This allows certain observations to be made at distances from the moon which are smaller than the avoidance radius, if they can be carried out while the moon is below altitude -5 deg. The default avoidance radius may be overriden by specifying the avoidance radius in individual observation requests.

• Max. random offset for target positions. This parameter specifies the maximum absolute value (expressed in arcseconds) of a small random offset which may be applied to the target position where each image will be taken. This offset is useful for minor planet observers who need to detect faint targets by their motion in a sequence of images. The random offsets decrease the probability that fixed detector defects will mimic the motion of the target when blinking the various images. Observers of stationary targets will normally set this parameter to zero.

• Frame mode. In all probability, every user will take light frames by default, rather than dark frames. The default frame mode may be overriden by specifying the frame mode in individual observation requests.

• Resolution. The three options high, medium, and low refer to binning factors 1, 2, and 3, respectively. The default camera resolution may be overriden by specifying the camera resolution in individual observation requests.

• Frame size. Users or large-format CCD detectors sometimes take partial frames employing only part of the detector. You may choose between full frames and center sub-frames which use one-fourth of the detector's area. The default frame size may be overriden by specifying the frame size in individual observation requests. This option is only available if the telescope is controlled by ACP using the MU image acquisition script.

• Filter. This specifies the name of the default filter to be employed in observations requested by this user. Filter names are listed in a text file whose preparation is explained in a previous section. The default filter may be overriden by specifying the filter in an individual observation request. This option is only available if the telescope is controlled by ACP using the MU image acquisition script.

• Image compression method. This specifies the image compression method to be applied on the user's science images. The available compression methods are listed below:
  • none means that no compression will be applied.
  • FITS means that the FITS images will be compressed using the Windows program Maxim DL. The user will need to use Maxim DL to open or uncompress his/her images. If Maxim DL is available to the user, this is probably the most convenient compression method. Compression rates are usually of the order of 50%.
  • zip means that the FITS images will be compressed using the program pkZip. Any zip program may be used to uncompress the images. Compression rates are usually of the order of 50%.
  This option is only available if the telescope is controlled by ACP using the MU image acquisition script.

• Exposure times. The user's standard exposure times should be listed in ascending order, one per line. These exposure times are used by the scheduler to automatically choose the exposure time for a given observation, according to the following rules:
  • The exposure time is determined by the target's rate of motion and by the image scale (expressed in arcseconds/pixel) for the camera resolution to be used in the observation.
  • The exposure time is chosen among the standard exposure times listed in the user's profile.
  • Targets which move less than a user-specified number of pixels during the longest (that is, the last) exposure time listed in the user's profile will be observed with that exposure time (note that this longest exposure time will be used by default to all stationary targets).
  • For faster targets, the scheduler chooses the longest standard exposure time during which the target moves less than the user-specified number of pixels.
  In this way, the scheduler ensures that fast-moving NEOs do not produce trailed images regardless of their rate of motion (of course, an object which moves several pixels during the shortest standard exposure time will produce a trailed image, but this can only be avoided by defining another, shorter standard exposure time). The use of standard exposure times is also convenient for image calibration purposes in case one uses a dark frame library containing darks for several exposure times. The above automated choice of exposure time may be overriden by specifying the exposure time in individual observation requests.