Iterative platesolve and slew

[amitshesh]

I wonder if sharpcap can support the following:

1. Platesolve and measure error between intended position and platesolved position.
2. If error is above a certain threshold, mount to slew to it's intended target AND GO TO STEP 1 ,else stop and declare success.

The part in caps is the new thing. The GPS button in the scope control tab could be made to behave this way.

Before sharpcap I used ekos, which has a slew to target function that does exactly this. Granted, it's platesolver is, for some reason, blazingly fast (astap comes close when it succeeds). But from the user's perspective, it's one button press and an iterative refinement to center the target starts with no further intervention. I have, on many occasions, witnessed ekos correct a massive error this way (also because it does not have the 15 degree range threshold that sharpcap has).

[admin]

Hi,

I guess that if you start out a long way from the correct co-ordinates (significantly more than 15 degrees) then the first plate solve/sync could put you merely in the rough vicinity of the right place. However in the more normal case of starting out 1 or maybe 2 degrees out (due to polar misalignment, cone error, etc), the first iteration is usually accurate enough. As you have guessed the 15 degree limit in SharpCap is tied to plate solver speed - to ensure that in normal usage the amount of time taken to plate solve is reasonable.

So I am afraid this feels like quite a niche request - happy to see if anyone else comes along and tells me I'm wrong about it though

cheers,

Robin

[amitshesh]

I have two reasons for requesting this, even after your reply:

1. Often when I use the GPS button, the target comes close to the center but not bang in the center. But pressing the button again manually makes the result better! This may very well be mount dependent (the az GTI in alt az mode for me), but the point is that the convergence seems to be non linear, and therefore is not always perfect in 1 step.

2. Given that sharpcap relies on external programs for both go-to and platesolving, effectively the result by the GPS button is also dependent on how good the platesolving and how accurate the model for the go-to is. An iterative refinement would help to make sharpcap's result less dependent on external things. Ekos can afford to do this because it does platesolve, go-to and refinement by itself.

I do agree on the slow platesolve hampering this. Since astap is significantly faster than the other platesolvers that are supported, perhaps this can be a astap specific functionality (e.g. in the settings).

[photon08]

I made almost the same FR at viewtopic.php?p=40647#p40647 .

This feature can help "poor" alt-az / Dobsonian users .