Vue d'ensemble du projet Audine

THE AUDINE PROJECT - OVERVIEW

The Audine project arose from the observation that the current cost of CCD cameras makes it virtually impossible for the average amateur astronomer to afford this technology, and this is regretable in the extreme. There is an inimitable sense of accomplishment associated with being able to digitally subtract air turbulence in order to capture the finest details in the images of planets. The observation of galaxies beyond magnitude 20, the ability to exploit the gathered data, and the knowledge that one has discovered a new object are all sensations unique to CCD observation.

The AUDE association finds the fact that many amateur astronomers cannot utilize this technology - in particular young people who are just begining in this field - counterproductive and regretable. We think that a CCD camera kit is an exceptional teaching tool that facilitates the introduction of the amateur astronomer to multiple disciplines. Moreover, we have found that the people who build their own CCD cameras are those who learn the techniques and technology best. Finally, we hope that a dynamic environment will be created between the current users and future users that will facilitate the exchange of information and mutual aid. All the technical principles, diagrams, procedures of assembly and development, as well as the software that has been developed are made public and is completely free if you do not trade with it. Our project is now your project as well.

Many amateurs have encouraged us, but this enthusiasm also worried us: would the AUDE Association be able to face the demand if the project becomes successful ? We believe that the AUDE Association cannot ensure the diffusion of a CCD camera for general use into astronomy. That is not our goal - our objective is to provide the details of a maximum number of elements of the Audine camera and where they can be found in the shops. We want the cost of this project to remain as low as possible.

The Audine camera is a rectangular box with sides equal to 80 X 80 mm (3.15 in. X 3.15 in.), the height is 90 mm (3.54 in.) and it weighs 600 grams (~1.32 lbs.). The CCD sensor is the Kodak KAF-0400 which has 768x512 square pixels of 9 microns. A system with a Peltier module cools the sensor. The readout noise is lower than 18 electrons. The digitization of the image is of 15 bits and the reading time is approximately 15 seconds for full resolution. The camera is connected to an IBM-PC compatible computer via the printer port. It is also perfectly possible to use Audine with a portable computer.

Currently, the camera does not have a shutter. Although this is normally not a problem, imaging of very bright objects such as the moon or sun without a shutter may damage the instrument. For all other astronomical objects, effective solutions are explained in this documentation.

The figure below shows a diagram of the Audine system:

A flat cable (maximum length 7 meters - 22 ft. 11 in.) connects the camera to the computer via the printer port. The acquisition software on the PC forms part of the system. Today there are 4 principal software packages:

PISCO. It functions under Windows 95 and soon under Windows NT. It is a very general program of acquisition. It is simple to use but its functions are powerful.
AUDACE for Windows 95. Its powerful language of script enables you to program sequences of acquisition corresponding exactly to your need. AUDACE is very modular. For example, the control interface can be installed on a computer and the parts of the program controlling the camera can be installed on another computer. One of the modules of AUDACE can also control the equatorial drive of the telescope. This software uses the concept of the client/server interface so that the various modules can initiate a dialogue through the TCP/IP protocol. You can thus work with a host computer while the camera is managed by a remote computer more than 50 meters distant. Moreover, another extension of AUDACE makes it possible to control the camera (and the telescope or other peripheral) through your Internet navigator. Thus, you can work with an astronomical installation located in another part of the world.
IRIS for Windows 95. It is used to process the images and some functions make it possible to configure the camera.
QMiPS32 for DOS (mode 32 bits). It is used specifically by the designing group of the Audine system to develop new digital acquisition techniques.

Currently, only PISCO and AUDACE can be downloaded from this site. The electronic part of the camera is on two printed circuits. The lower card comprises connectors (DB25 for the connection with the PC and DB15 for the power supply) as well as the circuits for the interface and the power supply. The higher card is comprised of the CCD, the configuration circuits for the clocks, the amplification circuits, and the analog-to-digital conversion circuits.

A voltage of +/-15V at ~ 40 mA powers the electronic part of the camera. Another power supply is used for the Peltier module which cools the CCD. This power supply also generates a voltage of +12V to actuate a ventilator. This ventilator is used to evacuate the heat produced by the Peltier blanket.
All the electronic parts are integrated in a metal box which you can mounted directly on the telescope.
The camera has a DB15 extension port , and has a 4-bit bus programmable by the computer. The applications of this bus are numerous: control of a filter wheel, of a shutter, of a telescope hand controller for self-guiding purposes...

For more information on the operation of a CCD, click here.