6 Image Display

6.1 Overview

In Part I Section 4.1 we described the two-phase plan for the DEIMOS image display. We focus here on the second phase.

There are long-term advantages to the choice of the NOAO RTD/PIE server.

• The image display will be deployed throughout the IRAF user community. Observers will already be familiar with its basic operation.
• The images will be directly available to IRAF without the need for intervening file writing.
• The message bus/plug-in architecture will permit interaction with tools that support individual observing programs. Any task will be able to connect to the DEIMOS image in real time.
• The field acquisition and mask alignment procedures described in Part II Chapter 2 can be written to use the message bus.
• It will facilitate automated focus and instrument diagnostic procedures.

The plug-in architecture means that each piece of functionality can be developed separately from the others.

Because the NOAO RTD server is at such an early stage of development it is difficult to be specific about the display modules and their mechanisms. We describe the first plug in that will be required for DEIMOS.

6.2 Figures

(none)

6.3 Nomenclature

Figdisp:

The image client program at Keck which can incrementally display LRIS and HIRES images in real time as the CCD computer transmits them.

NOAO RTD:

Real Time Display. The image display client program under development at NOAO for use with the NOAO Mosaic detector.

PIE:

Plug-in Image Extension server. The next generation of astronomical image display being jointly developed by SAO/CfA and NOAO.

Message Bus:

The underlying communications mechanism of the NOAO RTD and the PIE.

Distributed Shared Image:

A form of data storage managed over the message bus which permits multiple processes on multiple hosts to interact with an image.

6.4 Component Modules

6.4.1 Data Capture Agent

Function
receive data from the CCD crate and make it available to processes on the message bus
Language
C
Type
daemon
Author
Kibrick/Allen
Essay
This is a modified version of lickserv which will bridge the gap between existing Keck CCD systems and the PIE server.
Inputs
interleaved pixel streams from the CCD crate
Outputs
a distributed shared image
Deployment
Commissioning
Labor
120 hours

Keywords used by module
Reads DCS and instrument keywords destined for the image headers

6.5 Subsystem Procedures

(none)

6.6 Deliverable Documents

A section of the lickserv manual describing the connection to the NOAO message bus.