Astro-Physics |
What are Absolute Encoders and What Can They Do?
In order to meet the needs of the most demanding astro-imagers and researchers, we have integrated the optional Renishaw RESOLUTE Absolute Encoders into our 1600GTO and 1100GTO mounts. These encoders and readheads comprise a true absolute non-contact optical encoder system, which offers the latest in technological advances to ensure accurate and reliable performance in the field. What will this mean for you? Near perfect periodic error correction, virtually zero Dec. backlash and your mount will never be lost, which will result in greater productivity and hassle-free imaging sessions. Your mount will be invisible, as it should be. Consider these features when the absolute encoders are installed in both axes:
RESOLUTE uses a unique single optical absolute track (a world first) combined with sophisticated optics. The readhead acts like an ultra fast miniature digital camera, taking photos of the coded scale of the encoder ring. Photos are analyzed by a high-speed DSP to determine absolute position. The built-in position check algorithm actively checks every reading. Advanced optics and position determination algorithms are designed to provide low noise and low sub-divisional error. The result is unparalleled performance. |
The images below were taken using a 1600GTO mount with the Absolute Encoders installed. As mentioned earlier, the 1100GTO will use the identical encoders, readheads and software. Your results should be similar using either the 1600GTO or 1100GTO. |
Unguided exposure: 10 minute (600 seconds) |
Unguided exposure: 5 minute (300 seconds) |
This image consists of four ten minute exposures that were done at 1200 mm focal length with an SBIG STL-1100. It was done in Luminence filtration. No separate guiding was done. Click on the thumbnail to view the enlarged image. |
We feel that even longer exposures with refractors are feasible since, typically, they only have a tiny amount of flexure compared to mirror scopes. This is particularly true if the object is straight up. However, since many optical systems have inherent flex issues and possible mirror movements and tracking rates vary from one part of the sky to another, Astro-Physics Command Center (APCC) Pro version software (purchased separately) will provide additional corrections to make unguided imaging a reality for a wide variety of optical systems, assuming that the error is repeatable and can be modeled. Who Most Benefits from Absolute Encoders
Software Controls for the Absolute Encoders The commands related to the Absolute Encoders can be issued through the easy-to-use interface of the Astro-Physics Absolute Encoder Utility (Windows-based) provided on a CD-ROM. This program utilizes the Astro-Physics ASCOM V2 driver. As of late April 2018, we are finalizing the AE tab for APCC and expect it to be available in the near future. Requirement: The GTOCP4
control box and associated power cable are required for all
installations.
1600GTO R.A. and Dec. Absolute Encoders What’s Included:
Order 1600GTO Dec. Absolute Encoder Kit |
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Inc. - All Rights Reserved
This page was last modified:
April 28, 2018
Astro-Physics,
Inc.
11250 Forest Hills Road, Machesney Park, IL 61115, U.S.A.
Phone: 815-282-1513 Fax: 815-282-9847