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INDI Library v1.8.5 Released (19 Apr 2020)

April 2020 release of INDI Library v1.8.5 introduces new drivers while providing fixes and improvements to existing devices and core framework.

Polaris Hour Angle & GPSD

1 month 2 weeks ago 1 month 2 weeks ago by AstroNico.
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Polaris Hour Angle & GPSD #56153
Hello

I have a just setup an USB GPS module for my Pi4.
GPSD is working and VirtualGPS is disabled.

Do you know why "Polaris Hour Angle" is different between Ekos panel and INDI panel?
And which one should I use?


Thanks
Nico
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1 month 2 weeks ago
AradoSKYindi
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Polaris Hour Angle & GPSD #56161
Hello,

Location is in multiple places within AstroBerry. A quick check is to open GPSPANEL. The default location is Warsaw, Poland. If that is your location, then the clock of the PI has drifted. The PI does not come with an RTC. RPI cases are not RTC friendly. Look at PI time. Adding an RTC is doable with planning.

If GPSD is working, INDI Device Manager should accept GPSD when selected to do so. If not selected or not working, INDI takes the System.

This leaves us with the multiple places of location. KSTARS and PI have a GEOGRAPHICAL LOCATION. In PI and KSTARS, the default location is Warsaw, Poland. Change both locations to your geographical area. Then look at Polaris angle.

Synchronization of location is a manual effort. KSTARS is dependent on the OS for many time and location stores. INDI logs will show the clock difference between its time and the system.

It is an aesthetics issue. I like harmony. So, I normalized my AstroBerry. It should make smaller log sizes.
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1 month 2 weeks ago
AstroNico
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Polaris Hour Angle & GPSD #56166
Thanks.
"GPSPANEL" and "INDI-KSTARS-EKOS" both give my current location, retrieved from my GPS module, so I think that my GPS module & GPSD are working properly.

But I still don't understand why the "Polaris Hour Angle" is different between Ekos panel and INDI panel? There is more than 20minutes difference.

However, the HA value given by the left GPSPANEL seems closer to the correct one (the one I get with SynscanInit).

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1 month 2 weeks ago 1 month 2 weeks ago by Ihoujin.
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Polaris Hour Angle & GPSD #56167
I have seen this before. Often different polar finder apps calculate a different PHA. Without understanding what they are doing under the hood I can only guess as to why. But I've always suspected some do not factor in the Time Zone Meridian offset correctly.

Edit: Here are the results from various tools.
GPSD 2:03
KStars 1:37
SynscanInit 1:46
Stellarium: 1:37
Cartes Du Ciel 1:38

INDI/KStars on Raspberry Pi 4, 4gb
Raspbian Buster with AstroPi3 script configuration
Skywatcher HEQ5 Pro Mount
Canon 600D Camera
Orion SSAG/ASI120mm @280mm Guide Scope
PHD2
Adafruit Motor Hat shield
Adafruit GPS Module
Generic Bluetooth Joystick.
Startech 7 port powered USB Hub.
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1 month 2 weeks ago 1 month 2 weeks ago by AradoSKYindi. Reason: syntax
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Polaris Hour Angle & GPSD #56172
Hello,

The big take away from this is that each solution says to believe their story on where they think we are. In the meantime, our scope and its location are tied to a system. Each system must sync the mount to its internal clock. Therefore the polar pole has a million differences depending on where each system calculates its PHA.

The true test comes when the first GOTO and SYNC command goes to M81 and you see nothing by space. What is interesting is that KSTARS, Stellirium, and Cartes Du Ciel have very similar solutions. 1 sec difference is insignificant. No mention was given of syncronized clocks in these findings. The other are significantly different. Who does everyone believe?

I just recently added RTC to my RPI4B and RPI3B+. GPSD was nice but Raspbian and NTP don't mix. As proof, my RPI4B clock time was 1 hour behind the GPSD time in EKOS. I was puzzled. Then I remember the Raspbian and PI caviat about no RTC. Ok, the geographical location profile needs to be changed. Yes, I am not in Warsaw Poland.
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1 month 2 weeks ago 1 month 2 weeks ago by Ihoujin.
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Polaris Hour Angle & GPSD #56180

AradoSKYindi wrote: Hello,
No mention was given of syncronized clocks in these findings.


I had each application open at once with common location and time settings. Then quickly noted their figures to within the minute.

INDI/KStars on Raspberry Pi 4, 4gb
Raspbian Buster with AstroPi3 script configuration
Skywatcher HEQ5 Pro Mount
Canon 600D Camera
Orion SSAG/ASI120mm @280mm Guide Scope
PHD2
Adafruit Motor Hat shield
Adafruit GPS Module
Generic Bluetooth Joystick.
Startech 7 port powered USB Hub.

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1 month 2 weeks ago
AradoSKYindi
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Polaris Hour Angle & GPSD #56182
Hello,

Fantastic. Then the difference between is pretty significant. GPDSD +29 secs and SynscanInit +9 seconds is pretty big swag calculations.

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1 month 2 weeks ago
Ihoujin
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Polaris Hour Angle & GPSD #56186
It's worse than you think. The smallest significant figure I provided was Minutes, not Seconds.
GPSD 2:03:ss
KStars 1:37:ss
SynscanInit 1:46:ss
Stellarium: 1:37:ss
Cartes Du Ciel 1:38:ss

Also I live at Longitude 75°W, just a few kilometers from the Eastern Time Zone Meridian. So Time Zone offset is not a factor at play here.

INDI/KStars on Raspberry Pi 4, 4gb
Raspbian Buster with AstroPi3 script configuration
Skywatcher HEQ5 Pro Mount
Canon 600D Camera
Orion SSAG/ASI120mm @280mm Guide Scope
PHD2
Adafruit Motor Hat shield
Adafruit GPS Module
Generic Bluetooth Joystick.
Startech 7 port powered USB Hub.

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1 month 2 weeks ago
AradoSKYindi
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Polaris Hour Angle & GPSD #56226
Hello,

Thank you for the correction. Minute deviations are pretty dramatic. Even in minutes, KSTARS, Stellarim, and Cartes Du Ceil are more aligned than GPSD and Synscaninit. NTPD GPSD is supposed to not be working with Raspbian INDI. No hooks are in the process. This would explain its drift faster. Then again, NTPD requires configuration. That would make it a guess.

It should not matter the location of Polaris in one sense. We are looking at establishing the Celestial Pole. After that, time becomes critical. If not, deep space is all the view we will get. If we wait 8 minutes, the object will be in the view eventually.

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1 week 2 days ago
Kaczorek
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Polaris Hour Angle & GPSD #57762
Note that GPSD calculates Polaris Hour Angle for the time of last fix (the clock does not tick after), whereas sliding GPS Panel provides ticking clock synchronized with GPS (or system if you use Virtual GPS).
As the result Polaris Hour Angle displayed in sliding GPS Panel is current (and constantly changing), which is not the case for GPSD.

--
Radek Kaczorek
Astroberry Server | NEQ6 | Atik 460EX | Atik EFW2 | ASI 120MM

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1 week 2 days ago
jabian
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Polaris Hour Angle & GPSD #57802
“RPI cases are not RTC friendly”
Which problems they have ?
Stellarmate gadget comes with a RTC...

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1 week 2 days ago
AradoSKYindi
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Polaris Hour Angle & GPSD #57810

jabian wrote: “RPI cases are not RTC friendly”
Which problems they have ?
Stellarmate gadget comes with a RTC...


Hello,

Cases with heatsinks and fans around the big chip IC. Usually the RTC wants Pins 1,3,5, and 7 for the 3V device needs. This is where the conflict happens.

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