# -speed used during slewing
slew_spd 25 # speed relative to max. (in percent)
slew_spd_alert 100 # speed when initiating alert response
# -definitions of exposure lengths in seconds:
tshort 5 # short exposure length
tmedium 20 # medium exposure length
tlong 60 # long exposure length
max_moon 0.50 # max moon fraction to run a tlong;
# otherwise tmedium is substituted
# -cuts on angular positions of frame, sun and moon
min_elev 20.0 # min elev. for frame center (in deg.)
sun_elev 0.0 # max elev. of sun (in deg.)
moon_dis 30.0 # min distance to moon (in deg.)
First, the slew speeds are specified. For both normal slews and alert slews, the percentage of the maximum (as defined in schierd.conf) is given.
Next, the exposure length parameters. We have decided on standard values of 5 seconds, 20 seconds, and 60 seconds. Normal patrol operations use long (60s) exposures. However, when the moon is bright, the sky brightness can nearly saturate a long 60s exposure. Therefore, when the moon is up at its fraction is greater than max_moon, the exposure lengths are automatically stopped down to tmedium. Note, the system will not automatically take long exposures when the moon is brighter than that specified, either for regular sky patrols or for burst responses.
Finally, general cuts are made on what the telescope will image. A field must
be at least a certain altitude above the horizon: an azimuthially-dependent
number due to the elevation angle of the Declination limit switch on the mount
yoke. Simply put, the telescope cannot swing too far opposite the pointing
axis, or it will hit the yoke. In other directions, it can image closer to the
horizon. The sun must of course be below a designated negative altitude, and
the field must be at least 30
from the moon. These cuts are usually
only relevant for prompt burst responses. More stringent cuts can and should be
used for normal schedule items.