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5. Correctors, reducers, widefield lens systems
7. Rotating and folding M3 units
1. Autoguider units (AGUs) |
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For many applications, the high tracking accuracy of our telescope systems is sufficent. However, several special applications require a closed-loop autoguiding. Astelco's AGUs are beeing attached to the field derotators and allow precise tracking even on very long integration times.
2. Derotators |
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The ASTELCO field derotator is a proprietary design with a high speed motor, high precision worm wheel gear box and precision bearings without any backlash. This field derotator has been designed from scratch to create a unit that meets the fast slewing speeds of ASTELCO's high-performance telescopes without sacrificing the required performance and accuracy. All effects of field rotation are corrected in a precise and automatic mode.
The high speed of the field derotator guarantees that there are no
delays for the orientation and positioning of the instrumentation even
at maximum telescope slewing speeds. This means, when the telescope
reaches the target, the derotator also already reached its position and
the observation can start (this refers to an absolute rotational
position of the equipment like CCD cameras or others that need to be
positioned for example to North of the imaging field).
The ASTELCO field derotators accept loads up to 250kg without any
problem.
3. Autofocus systems |
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Precise temperature-compensated focussing is the basis for usable results. This system is included as standard equipment on our larger telescopes and is available as an option for all other systems.
4. Hexapod systems |
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On telescopes on the two meter class and above, movement of the M2 mirror is is done by a hexapod system, allowing for movement in all three axes including tilt. Thus, optical allignment and focussing can be easily acomplished by controlling the hexapod.
5. Correctors, reducers, widefield lens systems |
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For all telescope systems, a variety of field correctors, focal reducers and widefield lens systems are available to meet every possible optical configuration.
6. Wavefront sensors |
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These sensors are required to identify deviations in the wafefront created by the optical system, allowing for closed-loop corrections of for excemple active optic systems. ASTELCO can supply Shack-Hartmann wavefront sensors and others.
7. Rotating and folding M3 units |
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One of the most challenging tasks in ASTELCO's robotic telescopes is the precise and rapid switching of the light beam to any of the 8 possible Nasmyth foci. To accomplish this, the tertiary mirror M3 needs to be turned around the optical axis without losing collimation at any of the 8 possible Nasmyth foci.
Previous designs of the industry showed some flaws and therefore needed
to be improved. ASTELCO designed a new motorized rotating and
self-centering M3 unit to reach all Nasmyth foci by software control.
With this new design, rapid and precise focus changes between the
Nasmyth foci now get a simple standard task. Up to 8 different
instruments can be used at practically the same time. The new ASTELCO
design ensures reliable repeatability and perfect alignment at all times.
In telescopes that use the classical Cassegrain focus, the rotating M3
unit aditionaly can be folded away to allow the lightbeam passing
through M1.