2 Installation and Setup This section discusses planning and installation for a new or updated telescope configuration. For the most part, these topics do not arise during routine operation. The exception is the necessity to find the Home position each time the host computer is powered on, but even this can be configured to be performed automatically. Follows are the overall steps required to prepare a new installation for OCAAS, in a reasonable order. Some steps may not apply in some situations. · Prepare observatory building and infrastructure · Install OCAAS software · Install and configure computer cards · Edit configuration files · Connect GPS and/or set computer time and location · Align telescope axes using finder or eyepiece · Focus camera · Prepare second-order pointing mesh schedule · Calibrate and confirm dome/roof operation · Connect weather station 2.1 Preparing the Observatory A fully operational observatory is much more than OCAAS. OCAAS encompasses only the software aspects of an observatory. Issues such as environmental, electrical, safety, site infrastructure, building, personnel, security, hardware selection and so on are at least equally important but are beyond the scope of this document. 2.1.1 Data Dispensation One issue which can be discussed is the large amount of data which an automated observatory can generate and the implications this has on storing and retrieving that data. Consider a 1kx1k CCD camera with 16 bit pixels. Each image will be 2MB. If an average exposure is 60 seconds, one exposure is begun every 2 minutes, and the observing period is 12 hours long, then 360 images will be taken. Assuming the image files are compressed by a lossless method by a factor of two, this will require 360MB of disk storage... each night, night after night. If the observatory is operating at a remote site, this data must be retrieved, either through an electronic transmission or via removable media. A 56kbit/sec telephone modem operating at 5KB/sec throughput will require 72,000 seconds or 20 hours to transfer this data uncompressed. The slightest glitch and this scheme falls behind. An ISDN connection operating at 100kbit/sec throughput will require 10 hours. At least this will keep up. A 10mbit/sec ethernet operating at a sustained 200KB/sec throughput will require one half hour. This is very reasonable. An alternative to transmitting the data is to store it on mass media. This will require a small amount of time from a local site operator to attend media changes and arrange for the media to be mailed back to the home facility. This involves operational expenses for several sets of media to be in constant circulation, postage, and operator compensation. As an example of using current media technology using this scenario, that 360MB of data from one night could be stored on four 100MB Iomega Zip disks at approximately 7MB/$. Or, almost three nights of data could be stored on one 1GB Iomega Jaz disk at about 10MB/$. Or two nights on one CD-RW at about 30MB/$. Or, two nights on one CD-R at about 500MB/$ which is very cost effective indeed even if only a fraction was expected to be archived. OCAAS installations have been built using all of the above scenarios. Contact CSI for assistance in setting up scripts to manage automated dialing, networking, or media if needed. 2.1.2 Mount Installation The mechanical issues involved in properly mounting a telescope are many. But once it is firmly mounted, cables are securely positioned (beware of cable wraps at extremes of travel!) and the scope is ready for operation OCAAS includes tools to calibrate the axes and focus the camera. If the telescope is an Alt-Az mount with an image rotator, the reference rotation is also calibrated. There are effectively three methods each of which progressively refine the alignment, but even the initial procedure is often entirely sufficient for nominal tracking accuracy with a good mount. An exciting implication of fast axis alignment is the possibility of a portable telescope. Mounted on a suitable trailer or other mobile facility, such an instrument would be well suited for rendezvousing with transient phenomena including eclipses, occultations and grazing events. 2.2 Installing OCAAS Software You must have superuser privilege to perform the installation. OCAAS for Linux is normally distributed on a CDROM. Begin my mounting it as you would any CDROM on your system. For example, on a Linux system with a drive connected as the master device on the secondary IDE interface, the following command will graft the root of the CDROM file system to /mnt/cdrom: # mount -t iso9660 /dev/hdc /mnt/cdrom Then run the installation script as follows: # /mnt/cdrom/install It will begin by confirming that you wish to install OCAAS. You must then indicate whether you have executed a license agreement to operate OCAAS. If not, the script exits. Next you are asked the directory location for the new software. Installations are encouraged to use the default. If this is an upgrade, your current copy of the GSC catalog will be reused and all images, logs and config files in your current installation may be retained for your reference. Next the script insures there is sufficient disk space to hold the new software. Next the script will check for and create if Installation necessary a new user and group in /etc/passwd and /etc/group, respectively, both named ocaas. If this is an upgrade, the existing ocaas login, group and home directory will be preserved. That ends the questions. The script then copies the software to your hard drive; sets all files to be owned by ocaas user and group; edits /etc/ld.so.conf and executes /sbin/ldconfig to access the OCAAS shared libraries; and adds OCAAS boot capability to /etc/rc.d/rc.local. 2.3 Configuring Controller Cards The OCAAS PC uses specialized controller cards to communicate with the external hardware. Follows is a discussion of configuring the software to match each of the controller cards supported by OCAAS. Your installation may not use all of these controllers. 2.3.1 Apogee CCD Camera installation For the Apogee line of CCD cameras, the driver is in $TELHOME/dev/apogee.o. It is actually a Linux module with several parameters which must be specified when installed using the insmod utility. The array containing these values is called apg0. Most options can be read off directly from corresponding mnemonics in the .ini file supplied by Apogee when the camera is purchased. The parameters are as follows: