King rate, display, question


ap@CaptivePhotons.com
 

I may simply misunderstand, or maybe a minor cosmetic issue.

I wanted to try king rate while guiding, see if it made any difference.  Not expecting much, but maybe, and clouds are out and just experimenting until they clear. 

When I hit "set now" on the screen (which I already did prior to this screen shot) the bottom says "Tracking = Sidereal".   If I look at status window is correctly says King.

So the question in here is really this: if I don't want to take time to build a model, and am imaging low (bubble nebula for me from 26N), should kind rate be a better choice while guiding, perhaps producing less corrections? 

A model would be better of course, but sometimes I might be in a hurry (and I set up and tear down nightly). 

Linwood



 

My experience is that it's not going to make much difference unless you are doing both unguided imaging and are very low to the horizon



On Wed, Aug 18, 2021 at 6:12 PM ap@... <ap@...> wrote:
I may simply misunderstand, or maybe a minor cosmetic issue.

I wanted to try king rate while guiding, see if it made any difference.  Not expecting much, but maybe, and clouds are out and just experimenting until they clear. 

When I hit "set now" on the screen (which I already did prior to this screen shot) the bottom says "Tracking = Sidereal".   If I look at status window is correctly says King.

So the question in here is really this: if I don't want to take time to build a model, and am imaging low (bubble nebula for me from 26N), should kind rate be a better choice while guiding, perhaps producing less corrections? 

A model would be better of course, but sometimes I might be in a hurry (and I set up and tear down nightly). 

Linwood




--
Brian 



Brian Valente


Roland Christen
 

King ONLY has benefit if you are perfectly polar aligned. Typical King rate might change the tracking rate by 20 arc sec per hour for a given location, but if your polar alignment happens to be poor, you can easily get 60 arc sec per hour in the other direction at that same location. Thus totally swamping out any benefit from the King rate. It's also an average and doesn't really account for high or low temp, high or low atmospheric pressure, etc.
http://www.bbastrodesigns.com/equatTrackingRatesCalc.html

Rolando

-----Original Message-----
From: ap@... <ap@...>
To: main@ap-gto.groups.io
Sent: Wed, Aug 18, 2021 8:12 pm
Subject: [ap-gto] King rate, display, question

I may simply misunderstand, or maybe a minor cosmetic issue.

I wanted to try king rate while guiding, see if it made any difference.  Not expecting much, but maybe, and clouds are out and just experimenting until they clear. 

When I hit "set now" on the screen (which I already did prior to this screen shot) the bottom says "Tracking = Sidereal".   If I look at status window is correctly says King.

So the question in here is really this: if I don't want to take time to build a model, and am imaging low (bubble nebula for me from 26N), should kind rate be a better choice while guiding, perhaps producing less corrections? 

A model would be better of course, but sometimes I might be in a hurry (and I set up and tear down nightly). 

Linwood



--
Roland Christen
Astro-Physics


ap@CaptivePhotons.com
 

@Roland Christen:

 

  • King ONLY has benefit if you are perfectly polar aligned. Typical King rate might change the tracking rate by 20 arc sec per hour for a given location, but if your polar alignment happens to be poor, you can easily get 60 arc sec per hour in the other direction at that same location. Thus totally swamping out any benefit from the King rate. It's also an average and doesn't really account for high or low temp, high or low atmospheric pressure, etc.

 

Thanks.


Of course, thanks to Stefan and NINA’s new polar align, of course I have almost perfect alignment.  😊   Seriously efficient, fastest method I’ve seen, and seems very accurate.

 

I’m just learning all the things I can.  I guess the real answer is build a model.  Thank you for the advice.

 

Had a couple hours of clouds and experimentation is better than boredom.  Now it’s clearing and going to get my first try with the C11 on the AP1100.   And my target it high and I think I’m going with just the PA tonight despite being anxious to try the brand new NINA integration.

 

Clear sky is a luxury during rainy season in Florida.  Have to make choices.

 

Linwood