Starting with fast photometry
To get started with fast CCD photometry photometry, first start the
tcpcom program by executing the fastphot_start script,
and use it to obtain a frame of the field
that the telescope is (currently) pointing to.
Use the DS9 region feature to mark the target and reference windows
in the CCD image displayed by DS9, and create a list of target
coordinates. Next, convert the DS9 region output list to a format that the
tcpcom program can understand, using the photcnv program.
Transmit this list to the CCD controller from
tcpcom and start a sequence of integrations.
Windowed CCD integrations are then obtained and stored in cycles down to
a few seconds. The CCD data can be processed and the resulting light curves
displayed in real time with the rtp program.
How to start the tcpcom program.
- Sit in front of the screen marked "lisa".
- Log in to the computer tessa as obs (password provided
by staff).
- Type fastphot_start to start the script that will set up
the proper environment and start tcpcom in a separate window.
- Type ds9 to start the DS9 image display program.
Important points to get started:
- After the "tcpcom" command interface window has appeared, go to
page 2 (number keys change page)
to check that the filter wheel is coming to the right
position, and especially that the grism and aperture wheels
are out of the way (they must be in the open position = position 8).
If they are not, use the G-key and the I-key to get the grism
and slit out of the way. The FASU filters can be accessed from
page 3. Check that they also are in the open position.
The calibration lamp unit can not be accessed from tcpcom. If
somebody left the mirror in or any calibration lamp on the last time
ALFOSC were used, you must quit the tcpcom program and start ALFOSC
again to take the mirror out and/or turn off the lamps, before restarting.
- To use the software, refer to the software guide pages or check the
help pages on the system (accessed with the ?-key).
Output data directory:
-
All data files is stored in subdirectories below a top level
data directory decided for the current date when tcpcom is
started. These directories are ALL under /fastphot-data.
The name of
this subdirectory follows the naming convention from bias
(i.e. ka01 is Jan 1 2001).
A detailed description on how to set up windowed mode photometry is
given in the tcpcom guide.
For a description on how to run the Real Time Photometry program,
rtp, see the rtp guide.
How to exit the tcpcom program.
Before you exit tcpcom, make sure to put the transfer mode back to
'full frame transfer mode', using keystroke 't'. If you forget this,
the standard ALFOSC CCD control program BIAS will hang once you make
an exposure.
An alternative solution is to reset the CCD controller (staff only).
Last updated: 9/6 2006, Jacob Clasen.