Notes on QSO C Programs
It seems that there might be some confusion on C programs and
their availability for the queue mode. Here's some clarification:
- Grade and ranking for C programs are determined by the Time Allocation
Committee (TAC) for a given Agency. A C grade DOES NOT guarantee that
the program will be included in the queue program database. As explained
in the phase 1 Tutorial, telescope time is scheduled for A+B programs only
and C programs are considered for overfilling the queue.
- The final decision to include a C program in the queue for a given
semester is made by the QSO Team. This decision is based on several
As a result, you will rarely find more than 2 or 3 C programs for a given
Agency in the queue database for a given semester. Those are usually
found among the first 4 or 5 C programs ranked by an Agency at the most
and usually are well sufficient for the overfilling purposes of the queue
system. Only C programs appearing in the table published on the QSO
Web page for a given semester must have a phase 2 done by their PI. Also,
if a program C is accepted, it is possible that the amount of time allocated
differs from the amount requested, for the same reasons as given above.
- Ranking of the C program within the C grade for a given Agency.
- The conditions requested by the program, in particular the image
quality, sky background and RA of the targets, in the general context
of the entire database of programs. For instance, a C program requesting
0.65" has no chance to get any data; its priority will always be exceeded
by other A + B programs. C programs with strong time constraints are also
- It is useless to overfill the queue more than by about 25%. This
is the number we have used since we started QSO at CFHT. The completion level
is modest for C programs (more so with MegaCam due to bad weather, overheads,
and a lot of time-critical programs accepting modest IQ while normally we
would have used C programs). This has been a hard lesson of queue systems
for different observatories; it's a complete waste of time for the C program
PIs to overfill the queue by a larger fraction.