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click here for the russian version
To respond to the demand for a versatile and universally to use mount,
ASTELCO has developed the "New Technology Mount" NTM-500. Now in it's
second generation, the NTM-500 is a very compact but extremely versatile
mount for optics up to 60~70cm aperture. Using the technology of
ASTELCO's large telescopes (direct-drives, highly dynamic high-torque
motors, precision encoders, …), the NTM-500 slews with up to 100°/sec (depending
on equipment on mount), maintaining an absolute pointing accuracy of
less than 5 arc seconds across the entire sky!
Of course, software control of the NTM is done the same way as for the
larger telescopes. Remote control is a standard feature and robotic
software modules are available. Applications of the NTM include seeing
monitors, GRB-telescopes and others.
These images show one of the installations of the NTM-500 set up in equatorial mode used as a seeing monitor on Cerro Paranal, Chile.
The mount can be installed either "classically" equatorial, or as an
"alt-alt" mount with horizontal right-ascension-axis and used for several special
purposes.
The classical equatorial mode allows long-exposure imaging without the
use of an autoguider and without the negative effects of the field
rotation. The alt-alt mode allows continuous observation runs of regions
around the zenith without any limitations of the meridian transit.
The use of "state of the art" drive technology with this mount leads to
maximum dynamic (extremly accurate tracking and extremly rapid
positioning), and also to the possibilty of very high acceleration at
all slewing and tracking speeds with very short response-times and
therefore allows for the first time tracking accuracies like
professional large telescopes without periodic errors and well known
problems with gear backlash and friction at various temperatures.
The mount consists of a very stiff and rigidly designed housing of the
two large dimensioned hollow axles, the motor-encoder-
unit, the bearings
and the brakes.
The housing of both axles are made of a special aluminum alloy and are
anodized.
The axles and all other parts of the mount are made of stainless steel
and are therefore rustproof.
Positioning, pointing and tracking will be performed by high dynamic
torque-motors which are designed as absolute backlash free direct drives
without any gears. Together with the high resolution encoders which are
mounted on both axles, these motor-encoder units guarantee precise
pointing and tracking.
An internal brake-system for both axles ensure the necessary safety
during operation at all pointing or tracking speeds and also during
emergency cases like power failures.
Slewing speed* |
20°/sec |
Acceleration and Deceleration |
20°/sec² |
Absolute positioning accuracy** |
< 5 arcsec RMS ("Full Sky Blind Pointing") |
Differential positioning accuracy*** |
< 1 arcsec RMS |
Tracking accuracy without autoguider |
< 1 arcsec / 120min |
Tracking accuracy with autoguider**** |
< 0.3 arcsec |
* Typically used maximum positioning speed, up to 100 deg/sec possible with NTM-500
** With established pointing-model
*** Within a field of 1,5° radius
**** Depending on CCD pixel size
After establishing the pointing model there is no need of a further „referencing“
– the pointing will take place at once with maximum accuracy.
Beside all automatic and software controlled functions of the mount, a
local and manual control is possible with a wireless keypad.
Mount type |
"German Mount" |
Set-up mode |
Equatorial or "Alt/Alt" |
Material |
Stainless steel and aluminum, Special Alloy |
Bearings |
High precision roller bearings |
Drives |
Direct drive torque motors |
Drive accuracy |
No periodic error |
Dynamic |
> 1:4.800 |
Load capacity |
(Instrumental-load) > 60kg (plus counter weights) |
Latitude adjustment |
0–90° |
Azimuth fine adjustment |
±10° at any position (coarse adjustment 360°) |
Mount weight |
Approx. 85kg |
Mean power consumption |
750 W/230 V |
Max. power consumption |
1500 W/230 V |
The electric and electronic control of the mount is performed by the
ASTELCO control boards located in the control box, the software control
by the (customer supplied) computer hardware as well as the ASTELCO
basic software:
• Control box (industrial 19" standard) with power supply
• Wireless Keypad for manual telescope control
• ASTELCO basic software package
• Software network interface (accessible from the control box)
• GPS receiver
The control software runs on the computer supplied inside the control
box. The existing network interface allows controlling the mount with
external software. It can also be used for controlling the telescope
with a bunch of desktop planetarium programs such as The Sky or SkyMap
Pro for Windows or Xephem, etc. for Linux. Drivers for these programs
are available.
Jumbled Galaxy Centaurus A (2007, Jun. 30)
Spiral Galaxy M83 - The Southern Pinwheel (2007, Jul. 24)
