General Overview

SHARC-II is relatively straightforward to use, though might be daunting for the first-time user. The purpose of this document is to go over the basics, so that the rest of the more detailed documentation is easier to process.

You will spend most of your time in front of a single computer, named "kilauea". From it, you access other computers that play different roles in the data aquistion. The main "sharcii" computer is responsible for reading out data, and via a "server", provides realtime data to "clients" that display it. The clients also allow the user to initiate integration, set exposure times, etc. The "sharcii" computer reads the data and stores it to a file. After each integration, it also copies the file to a remote system, currently /halfT on "lapakahi". Kilauea is used to reduce data while at the telescope. It can be done in near-real time, allowing the user to assess the data quality, pointing issues, etc. To control the telescope, a program called "UIP" is used. It is run on kilauea.

Optionally, but recommended, you can use the "tpick" computer to control the DSOS. This system actively corrects the surface of the CSO dish, providing stable and near-diffraction limited beam profiles independent of zenith angle.

Computers and how they talk to each other.

You will be using 5 or more computers to operate SHARC-II. Below we list the name of each and the role it plays.

sharcii

• The most important system, as it interfaces with the SHARC-II electronics
• Is a rack-mounted SUN which resides in the Lounge
• Runs the "IRC SERVER", which transfers data to clients
• Saves data locally, as well as transfers a copy to the lapakahi computer
• Runs the Helium fridge cycling program (although usually displayed on the lapakahi console)

kilauea

• The computer you have most direct contact with
• Is a SuSE LINUX machine in the control room
• Runs the "IRC CLIENT", which controls SHARC-II (Integration time, etc)
• Runs the UIP, which controls the telescope
• The computer typically used to reduce data at the telescope.

lapakahi

• Stores copies of SHARC-II data; disk (/halfT) mounted onto kilauea.

tpick

• Runs the DISH SURFACE OPTIMIZATION SYSTEM (DSOS).
• Typically is logged in from kilauea