1100GTO Absolute Encoders -
Installed on 1100GTO-AE and 1100GTO-AEL
In order to meet the needs of the most demanding astro-imagers and researchers, we have integrated the optional Renishaw RESOLUTE Absolute Encoders into the 1100GTO-AE and 1100GTO-AEL 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 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 Pro version software, purchased separately)
provides 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. Tests at the University of Hawaii with our 3600GTOPE
equipped with an R.A. Precision Encoder and using the APCC
Pro version with the APPM pointing model (beta version) already have
shown that unguided exposures are possible with large Ritchey-Cretien
imaging scopes. This will greatly enhance their research program.
Software Controls for the Absolute Encoders
Note: The Astro-Physics Command Center (APCC) software is not included as part of this package. It is available as an optional purchase.
1100GTO-AE and 1100GTO-AEL: If you plan to use Absolute Encoders, we encourage you to order your mount with the R.A. and Dec. encoders fully installed and tested prior to shipment.
Absolute Encoder Upgrade Option: If you decide at a later date that the Absolute Encoders will enhance your imaging sessions, you can order the kit to install yourself. This kit will include all of the parts required. The system will be tested as a whole prior to shipment to ensure that all components are functioning properly. In order to complete the assembly, a little manual dexterity is required to position the screws in a restrictive space. We will provide detailed instructions to guide you through this process. This kit will not be available until sometime in 2016.
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This page was last modified: December 27, 2015
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