Remote Observing Manual

This manual documents the remote observing operations of Shared Skies. It covers the basic elements of all of the telescopes available remotely, and provides links to information about robotic observing and data archives. Other shorter pages are available as well. Please check the index for those.

Overview

System Architecture

Each telescope, its instruments, and its enclosure are controlled by a single computer system connected to the hardware. For different instruments there are other network components for power control and live video. The telescope operator and the observers do not have to be on site because these components are accessible remotely, either through the Internet by secure login and encrypted transmission, or through servers that limit functionality while insuring safe reliable, largely robotic, operation.

Remote Observing

In remote observing use, the telescope may have an operator on site and an observer off site, or it may be operated entirely by an off site observer-operator. In the latter case, when a fast network with low latency is available, the observer can have very effective control of the telescope in real time. Under less favorable conditions, the observer may make use of scripted operations and use a server on the high speed network to take on more automatic control of the system. Fully robotic operation based on queued requests is planned for some of the instruments in our network, but is not yet available.

Each telescope with its instruments and enclosure is under the control of a single computer system that is running INDI, an flexible instrumentation server protocol that accommodates several devices and clients simultaneously. In this way the observer may have control of the telescope while the operator stands by and monitors events, or the operator may take control as needed while the observer works with the data pipeline. Indeed, the "observer" may simply be another server on the network placing requests to the INDI server at the telescope. The essential software components that enable this process are

XEphem: an astronomical ephemeris, interactive sky map, and instrumentation interface

XmTel: a telescope control panel

XmCCD: a camera and filter wheel control panel

ds9: interactive image display spawned by xmccd

XmGuide: an autoguider controlpanel

XmDome: a dome rotation and shutter control panel

INDIServer: the remote server

Drivers: ccd, dome, tel, guide or others that talk to the server

All of the clients (XmTel, XmCCD, ...) are simply user interfaces to the INDI protocol. XEphem has a "control panel" that offers full access to the commands enabled by the hardware drivers, but it is not as convenient to use as the the individual panels. (At this time xmguide and xmdome are not available in indi versions, but their functions are handled by xephem.)

The server system is accessible on the command line with getINDI and setINDI issued on a system which has access to the port on which indiserver is running. With these commands a number of scripted utilities have been built to handle routine tasks such as starting the observations or running a sequential queue of images.

Connect to the Telescope Computer

The telescope operator and the remote observer must have an account an password on the telescope computer system, and must be working on a network where the firewall enables a connection. If the observer or operator are outside the firewall, they can have access only through the secure but limited web interface.

A Virtual Private Network (VPN) account may enable access from outside the universities. A VPN user appears to our systems as being within the campus originating from a specific range of IP addresses that are known beforehand to us. Once a telescope user has a VPN account we can test it with our system to insure they have access to the observatory networks. Note that the firewalls of both the University of Louisville and the University of Southern Queensland generally do not offer unlimited access between campuses. For example, if a user at USQ wants to directly control a telescope at Moore Observatory they must also have an account on one of the servers, because only the servers are open to USQ. For this reason, remote operation between Australia and the US is best done from a campus or observatory location. The additional advantage of this is that it offers use of videoconferencing and an observer on one campus may have telepresence at the remote observatory.

With those constraints, a command line to connect to CDK20S is

ssh -Y user@crux.mko.usq.edu.au

with a response to the request for a password. User names and passwords are provided to authorized users.

Passwordless login

Secure Shell (SSH) permits secure passwordless login with public/private key encryption. (More coming ...)

Tunneling for INDI with SSH

Secure Shell permits tunneling through the firewalls to pass the ports used by INDI from one system to another. (More coming ...)