On Sun, Aug 25, 2024 at 10:04 AM, Ed Harp wrote:
by spirit level, I would guess you mean the "CWD"
Yes, just some best practice thoughts. ?Aligning the four G11 mount spirit levels sets the mount into a mechanical position that corresponds with the initial Gemini-2 encoder position. ?The starting physical orientation of CWD and the corresponding controller state, a Cold or Warm Start, are synchronized through the encoder values. ?The simplest method involves setting the mount to CWD while powered off, and once Gemini-2 is powered on and passes the Cold Start, tracking begins. Other startup sequences just need to consider the end goal. ASIAIR expects the mount to be operational, similar to other controlled hardware, upon APP connection. If the startup process includes parking the mount, unpark afterwards for ASIAIR. Should the mount require Asmuth rotation for Polar Alignment, it now remain level to maintain accuracy with the encoders. Eventually, the mount will slew to the first bright star for sky alignment, which relies on the precision of CWD. Any movement disrupting the CWD's alignment with the encoders necessitates a return to the leveling process.? It's documented but seems to get lost in the details at times.
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On the Meridian Filp, that was about a behavior you noted.? The type of OTA and mount set up influences the use.? Scott's enhancements enable the mount to track for hours past the Meridian with the appropriate OTA, which can sometimes eliminate the need for a Meridian Flip.??While the behavior that ASIAIR uses, a Go-To depends on the characteristics of the mount.? If Gemini-2 has two positions it can reach a target, it always does a Go-To to the closest position. ?This can cause the topics to become interwoven.
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This involves the Limits.? As targets move across the sky, they also traverse over and past the mount's limit points. ?When using a Go-To function for a target on the West Side, ASIAIR requires the target to drift to a position accessible only from the East Side to perform a Meridian Flip. This position on the East Side becomes reachable only when the target moves beyond the EAST Limit and the start of the WGL Limit (the WEST minus WGL position). Both conditions are necessary for the flip.
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These criteria subsequently affect the limit parameters. If the OTA permits shooting beyond the Meridian, keep the ASIAR delay parameters at zero; it's all about the limits. If the OTA makes contact at or before the Meridian, then delays are necessary to meet the criteria. However, if your OTA target can bypass a Meridian Flip by continuing to track past the Meridian, then disabling it is another excellent option.
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This can also occur with equipment like a long refractor, where the camera cannot make contact at the northern leg latitudes. In such cases, with relaxed limits and exercising caution it’s possible to track through the meridian too.
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Doug
