How much is the appm model affected by temperature?


Tom Blahovici
 

Hi
The reason I ask is that I have 3 temperature sensors on my telescope.
One is the VBox, one is the thermocouple from a Moonlite Nitecrawler and one is a high accuracy sensor called SensorPush.
Last night when imaging, the values obtained from each, respectively were -25C, 21C, and 23C.
How can I trust these values and how much do they impact the model?
Tom


 

Hi Tom

in my experience, temperature affects it enough that you want to look at this. 

I suspect it's less critical whether the temperature is exactly accurate, and more important that you use the same source for building the model and during subsequent tracking. I think temp differences are important as a relative measure, not absolute (Ray's answer would trump mine of course)

On Thu, Jan 27, 2022 at 6:28 PM Tom Blahovici <tom.va2fsq@...> wrote:
Hi
The reason I ask is that I have 3 temperature sensors on my telescope.
One is the VBox, one is the thermocouple from a Moonlite Nitecrawler and one is a high accuracy sensor called SensorPush.
Last night when imaging, the values obtained from each, respectively were -25C, 21C, and 23C.
How can I trust these values and how much do they impact the model?
Tom



--
Brian 



Brian Valente


Ray Gralak
 

Tom, you want to use air temperature because it is used for the refraction calculation. And, you want it to be as accurate as possible. Which reading do you believe is correct? There is a big difference between -25C and +21/23 C, or is there a typo?

-Ra

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of Tom Blahovici
Sent: Thursday, January 27, 2022 6:28 PM
To: main@ap-gto.groups.io
Subject: [ap-gto] How much is the appm model affected by temperature?

Hi
The reason I ask is that I have 3 temperature sensors on my telescope.
One is the VBox, one is the thermocouple from a Moonlite Nitecrawler and one is a high accuracy sensor
called SensorPush.
Last night when imaging, the values obtained from each, respectively were -25C, 21C, and 23C.
How can I trust these values and how much do they impact the model?
Tom


Tom Blahovici
 

Typo. All at - degrees. Brrrrr


Ray Gralak
 

Typo. All at - degrees. Brrrrr
Okay, then the few degrees C difference between the readings will not matter much.

-Ray


Marcelo Figueroa
 

I have found in my semi permanent installation that modeling needs to be done at least 2 times a year, one for winter and one for summer.
 
The winter model works perfectly for several months, until at some point in the summer the stars start to appear a little oval, it is time to redo the model. Here the average winter temperature during the night is around 4º C and during the summer it can reach around 19º. And to input the temperature into APCC I use a Pegasus device.