Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/~palfa/doc/za_limit_instructions.txt Дата изменения: Wed May 19 20:50:10 2010 Дата индексирования: Sun Apr 10 21:34:59 2016 Кодировка: Поисковые слова: deep sky

---------------------------------------------------------------------
Instructions for observing with the ZA limits imposed on slewing and
tracking due to overstraining the platform structure.
---------------------------------------------------------------------

NOTE 1: During the night (approx. 7pm - 7am), slewing and tracking is allowed
in the ZA range between 3.5 and 12 degrees. During the day, slewing and
tracking is allowed in the ZA range between 6 and 10 degrees.

NOTE 2: There is NO warning in CIMA if the current source goes outside the
allowed ZA range--the telescope will just silently stop tracking the source
when it has reached the ZA limit. You can watch the telescope's current AZ & ZA
in aostatus (run 'aostatus &' on the command line.)

NOTE 3: Telescope status (Tracking, Slewing, Settling, or Not Tracking) is
displayed in aostatus. If the telescope hits the ZA limit during the
observation, tracking will stop, status will change to Not Tracking as the
source drifts out of the beam, but data taking will continue until you abort
the observation or requested obs. time is over.

1. Start the 'smart' version of cima. Enter p2030 as the project ID and your
name/initials for observer. Select 'Pulsar' and click 'Accept.'

2. Several windows will open. In the 'Receiver Selection Menu' window, select
ALFA, and click 'Accept.' The receiver will rotate into position. You can watch
the telescope status in aostatus or the 'CIMA observation status' window.

3. In the 'CIMA Main Menu' window, click 'Load Configuration'. Load the file
'ALFA_P_Mocks_smart.conf. Click 'Load and Apply'. A 'CIMA Observing Menu'
window will open. (Applying the configuration takes a bit. When it's done, in
the 'CIMA Observation Status' window on upper right, the green square will say
Idle.)

Loading the configuration file also sets up ALFA rotation and loads the catalog
za_limit.cat. This catalog contains pointings from the C grid only with
|b| < 2deg and 10deg < Dec < 26deg. The telescope will start slewing towards
the first source of the catalog.

4. Click on 'Backend Control' in the 'CIMA Main Menu' on the left. A 'Mock
Spectrometer configuration menu' window will open. Click on 'Adjust Mock Power.'
Mock power levels will get printed in the 'CIMA observation log display' on
the lower right. The first 4 columns of numbers should be close to 30.
Approx. 25-33 is ok, much less than that means you are not getting power in
some beams--if that is the case, tell the operator.

Each pair of lines in this output corresponds to one beam (there are 2 Mock
bands per beam), and power for each polarization (A or B) is measured
separately. If only one beam or one polarization of one beam is dead, it's
still ok to observe.

(Possible trivial reasons for not getting power in *any* of the beams: the lid
has not been taken off ALFA after a radar run, or a master switch has not been
turned on after maintenance.)

Dismiss the 'Mock Spectrometer configuration menu'.

5. In the 'CIMA Main Menu', click on 'Pointing Control.' All pointings from the
za_limit.cat catalog will be displayed, along with their current AZ & ZA, time
to rising/setting, and slew time to each. Note that the rise/set times are
with respect to the normal telescope 'horizon', which is ZA=19deg, not the
current restricted ZA range.

With the ZA restrictions, making reliable schedule files would be very
difficult, so observing is manual until the restrictions are lifted.

6. In 'Pointing Control', select a pointing whose ZA is within the allowed
limits, and click 'Apply'. After the telescope has slewed to it, in 'CIMA
observing menu' click 'Observe' (if this is buried below a mass of windows,
you can bring it up by clicking 'Pulsar Observing' in the 'CIMA Main Menu').

7. In 'Pointing Control' you can click on "Show Graphically" to see where the
telescope is looking at in AZ/ZA, and where the grid of pointings is in AZ/ZA.

--If the current source goes outside the allowed ZA range, abort the
observation ('Abort' button in 'CIMA observing menu' or 'CIMA log display') and
select another source.

--If none of the PALFA search pointings are within the allowed ZA range at the
start or end of the session, you can observe some known pulsars. In 'Pointng
Control', click on the catalog name on upper right. Then 'General Catalogs' and
select psr.cat or psr_bright.cat and 'Accept'. To go back to our catalog,
click on the catalog name, 'Project Catalogs', za_limit.cat, and 'Accept'.

--Keep track of what pointings you have observed and after the session is over,
comment them out in the za_limit.cat file (# in the beginning of a line will
mark it as a comment and that pointing won't show up in Pointing Control next
time). The file is in /share/obs4/usr/pulsar/p2030; if you don't have access,
send me (deneva@naic.edu) a list and I will mark the done pointings.