The first part of schierd.conf is self explanatory:
# configuration file for schierd
# format is "key value"
# comments start with `#' and go to end of line
# blank lines are okay
# lines cannot be continued
loglevel 1 # 0,1,2 = terse,verbose,debug
poll_time 0.1 # main loop time quantum
sample_time 3.0 # sample time in seconds
mntman AlanSchier # mount manufacturer
mntmodel Equatorial # mount model
mntsn 2 # mount serial number
errormail email@example.com # where to send error messages
The next section contains numbers that should be general across the Schier
enctol 300 # tolerance for encoder stop
slewacc 16.4 20.6 # acceleration for mount (deg/s2)
maxvel 35.0 35.0 # slew velocity for mount (deg/s)
homevel 2.0 2.0 # velocity to find home (deg/s)
stowpos -85.0 35.0 # Stow pos. in Axis coords (deg)
standbypos -85.0 140.0 # Standby pos. in Axis coords (deg)
deg2enc 24382 19395 # encoder counts per deg
rarange -185.0 0.0 # range of the ra axis (deg)
decrange 0.0 220.0 # range of the dec axis (deg)
foctol 0.001 # focus tolerance
The acceleration and velocity parameters are stated in degrees for the RA axis (axis 0) first, and the Dec axis (axis 1) second. The deg2enc values were calculated from the radius of the encoder tape on each drive wheel. The RA range and Dec range were determined experimentally, and are just short of the hardware limit switches. Under normal operation, the mount controller should never be told to move the telescope to an illegal position, and we have multiple redundancies. The maximum velocities were determined by how fast we could move the telescope without any odd noises coming from the mount. (Very scientific, eh?) The home velocity is the default from Mr. Schier.
The stow position is (for the northern hemisphere) pointed north, slightly
below the horizon. The standby position is very close to the zenith. These
values can change depending on the polar alignment of the telescope.
# the following keyword defines a file that contains the 2-star rotation matrix
matfile /rotse/run/etc/mat0529c.mat # full path
# The following keyword defines a file that contains a tpoint model
modfile /rotse/run/etc/mod_011211c.dat # full path
focusmodfile /rotse/run/etc/focusmod011214.dat # full path
obsfile /rotse/run/etc/observatory.conf # site information
statdir /rotse/data/pipeline/prod # idlpacman stat dir.
statroot rotse3a # root for statfile
The matfile matrix file specifies a two-star pointing model matrix file. The modfile is a Tpoint pointing model file. If a Tpoint model file is specified it will use this pointing model instead of the two-star matrix. The lines containing matfile and modfile can be commented out if no relevant pointing models exist. The modelling schierd decides to use is logged in /var/log/rotse.log. The obsfile is the observatory information file used for coordinate conversion.
The focusmodfile focus model file specifies the constants for the bilinear focus model fit. The format is described in Section 3.8.1.
Due to the homing inaccuracies of the Schier mount (the homing can drift by tens of arcminutes), the first calibrated image of the night is used to improve the home position. The automated calibration pipeline outputs a summary of each calibrated image in a file called statdirstatroot_stat.dat. After a home command, schierd checks every ten minutes for the most recent calibrated image that was taken after the most recent telescope homing, and updates the offset values. This improves pointing considerably.