---------------------------- General software description ---------------------------- The software which normally runs OPTIC is called "otcom". The location of all software is /usr/local/inst, where subdirectories include bin - binaries, should be first in path config - setup files for telescope and filter wheel doc - documentation dsp - DSP code for the SDSU controller etc - sample save files and sound files pro - Vista procedures script - scripts for otcom src - source code for otcom and other programs The normal place where data are saved is /b0/optic. This should be writable for all users. General observers normally should log in as "obs" and there is a root account known as "otroot". See somebody knowledgeable about passwords. When otcom starts up it first checks to see whether it can communcate with the interface, initializes it, then checks to see whether it can communicate over the fiber to the SDSU controller. If so, it reads a telescope configuration file and filter definition file. Finally, it begins accepting socket connections from client program(s) which is typically the TCL GUI called "otgui", as well as accepting commands which are typed at the window where otcom is run. An important thing to do at this point is to "download the DSP code". The DSPs in the SDSU controller boot from ROM, but need specialized code which is adapted to the particular CCDs and hardware connections and which can run the needed routines. For OPTIC, the normal DSP code is called "optic4.lod" for the timing board and "opticlub.lod" for the utility board. These are automatically downloaded when you type "df" at otcom. In principle this ought to be done as part of the initialization, but it isn't (yet). Otcom has a very simple interpreter which accepts commands (any unique abbreviation is acceptable and case does not matter), and carries out actions such as "clear 4" (clear the CCDs four times), or "go" (perform a readout", or "status" which lists the important variables and state of the camera. These will be detailed later. The GUI allows the user most of the functionality of the command line interpreter in a more intuitive graphical format, but it is important to realize that the standard input of otcom is normally accessible for typed commands. Each command which the GUI passes on to otcom is echoed in the GUI's log window, and these commands can be typed directly in the "Command:" entry window of the GUI or at otcom's standard input. The reason that it's worth going beyond the GUI is that otcom has a script facility (described below) which can be extremely useful, but it only uses the command set, of course. Most of the communications from otcom are shown in the log window of the GUI but not all. In particular, if otcom requires interaction with you, perhaps because you entered a command with unacceptable arguments or because you are trying to overwrite an existing file, it does so via the otcom's standard input, *not* the GUI. Therefore otcom should never be run purely as a server in the background, but should be run as a normal program in a window of its own. If OPTIC is run as a conventional CCD there are no other windows which the user needs to know about. However, if OPTIC is run with guide stars or in tracking mode there are two other windows which might appear. The command "FGS" (Find Guide Star) takes a quick exposure of the lower CCD regions (i.e. bottom 516 pixels), binned 2x2, and pops up an image from which the user can select guide stars. Its use is described below in detail, but this is how the user chooses stars (or not) for guiding and enters the coordinates. When the user has selected "OT" mode and starts an exposure, another window, called "XOPTIC", pops up which shows video of the guide stars and various statistics about them (also described in detail below). Finally, OPTIC has a few utilities which are good to know about. One is called "othead" which will dump out one line of header information from an exposure (or a title line with no argument). This is helpful for making an automatic log of a night's observing. See Manual_utilities for more details. Another useful utility is "mkfinder" which will download a 15 arcminute image from the Digital Sky Survey, overlay an OPTIC footprint, and write a postscript file which you can print. The third important utility is called "conflat". The result of OT shifting an image is that each pixel in the final image has actually been integrated on a variety of physical pixels. An exposure during which OT shifting has taken place normally writes several auxiliary files in addition to the final image: myprefix_fgs.??? - guide star locating image used by fgs myprefix_gsc.??? - guide star locations which were chosen during fgs myprefix_gs.??? - table of guide star locations and properties myprefix_ot.??? - table of where each pixel was integrated myprefix_tg.??? - telescope guide commands (if enabled) myprefix_vid.??? - 3D FITS file of all video images Conflat takes an unshifted, unbinned flatfield and convolves it according to the data in the '_ot' file so that it agrees with the OT convolution which took place in the image file. A note about file names. In some people's opinion, a mandatory suffix of ".fits" for FITS files is stupid and contributes to the general problem of RSI, and the refusal of the FITS standard to recognize unsigned 16-bit integers also stupid, given the properties of A/D converters, and is curiously in conflict with the 2880 byte block size and mandatory byte order on which FITS is based. Otcom by default writes files which consist of a prefix and a 3-digit suffix, e.g. "/MI5/bond.007", and writes *unsigned* 16-bit integers. If you don't like the file names, create a script which will rename them after the fact. If you insist on *signed* 16-bit integers (with an appropriate BZERO), you can use the "set" command described below to enable it. (030120: I've knuckled under to the GUUC and made signed FITS files the default.)