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PHD2 How to calculate total RMS Error from log file?

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#1 vland

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Posted 14 July 2021 - 07:18 AM

Hi, I'd like to create a small program to show the current RMS error, like seen in PHD:

 

 phd2rms.jpg

 

I think guess I should be able to do that starting from PHD2 log, using the Root Mean Squared function? 

how can I do that? this is the log for the current image

 

 

thanks for any input

Guiding Begins at 2021-07-14 14:05:14
Equipment Profile = Sim
Dither = both axes, Dither scale = 1.000, Image noise reduction = none, Guide-frame time lapse = 0, Server enabled
Pixel scale = 4.30 arc-sec/px, Binning = 1, Focal length = 240 mm
Search region = 15 px, Star mass tolerance = 50.0%, Multi-star mode, list size = 10
Camera = Simulator, gain = 95, full size = 752 x 580, have dark, dark dur = 1000, no defect map, pixel size = 5.0 um
Exposure = 1000 ms
Mount = On Camera, connected, guiding enabled, xAngle = -166.4, xRate = 3.108, yAngle = 104.9, yRate = 3.439, parity = ?/?
Norm rates RA = 13.4"/s @ dec 0, Dec = 14.8"/s; ortho.err. = 1.3 deg
X guide algorithm = Hysteresis, Hysteresis = 0.100, Aggression = 0.900, Minimum move = 0.190
Y guide algorithm = Resist Switch, Minimum move = 0.190 Aggression = 85% FastSwitch = enabled
Backlash comp = disabled, pulse = 20 ms
Max RA duration = 2500, Max DEC duration = 500, DEC guide mode = Auto
RA Guide Speed = Unknown, Dec Guide Speed = Unknown, Cal Dec = Unknown, Last Cal Issue = None, Timestamp = 7/14/2021 2:05:14 PM
RA/Dec = Unknown, Hour angle = Unknown, Pier side = Unknown, Rotator pos = N/A, Alt = Unknown, Az = Unknown
Lock position = 490.123, 110.907, Star position = 490.123, 110.907, HFD = 2.32 px
Frame,Time,mount,dx,dy,RARawDistance,DECRawDistance,RAGuideDistance,DECGuideDistance,RADuration,RADirection,DECDuration,DECDirection,XStep,YStep,StarMass,SNR,ErrorCode
1,1.147,"Mount",-0.073,-0.115,0.098,-0.097,0.000,0.000,0,,0,,,,628838,159.15,0
2,2.256,"Mount",-0.094,0.041,0.082,0.060,0.000,0.000,0,,0,,,,602034,148.36,0
3,3.371,"Mount",-0.154,0.075,0.132,0.106,0.000,0.000,0,,0,,,,608425,149.52,0
4,4.482,"Mount",-0.173,-0.072,0.186,-0.033,0.000,0.000,0,,0,,,,638570,153.85,0
5,5.594,"Mount",-0.006,-0.000,0.006,0.001,0.000,0.000,0,,0,,,,637409,144.31,0
6,6.702,"Mount",0.067,-0.220,-0.013,-0.229,0.000,0.000,0,,0,,,,681398,154.81,0
7,7.829,"Mount",0.030,-0.119,-0.001,-0.123,0.000,0.000,0,,0,,,,656855,160.86,0
8,8.952,"Mount",-0.061,-0.090,0.080,-0.074,0.000,0.000,0,,0,,,,635812,155.23,0
9,10.075,"Mount",0.033,-0.032,-0.024,-0.039,0.000,0.000,0,,0,,,,655001,160.31,0
10,11.199,"Mount",0.024,-0.133,0.008,-0.136,0.000,0.000,0,,0,,,,672288,158.48,0
11,12.325,"Mount",-0.155,-0.126,0.180,-0.090,0.000,0.000,0,,0,,,,660940,146.98,0
12,13.449,"Mount",0.086,-0.192,-0.038,-0.205,0.000,0.000,0,,0,,,,701362,171.31,0
13,14.570,"Mount",0.113,-0.136,-0.078,-0.157,0.000,0.000,0,,0,,,,694932,167.85,0
14,15.693,"Mount",-0.111,-0.122,0.137,-0.095,0.000,0.000,0,,0,,,,626583,160.86,0
15,16.888,"Mount",0.079,-0.275,-0.012,-0.286,0.000,-0.243,0,,71,N,,,704247,163.82,0
16,18.046,"Mount",0.043,-0.226,0.011,-0.230,0.000,-0.195,0,,57,N,,,685731,163.88,0
17,19.240,"Mount",0.036,-0.381,0.055,-0.380,0.000,-0.323,0,,94,N,,,689950,162.91,0
18,20.405,"Mount",0.061,-0.255,0.001,-0.262,0.000,-0.223,0,,65,N,,,705189,153.57,0
19,21.613,"Mount",-0.176,-0.239,0.228,-0.196,0.184,-0.167,59,W,49,N,,,653598,170.66,0
20,22.828,"Mount",0.270,-0.397,-0.169,-0.445,0.000,-0.379,0,,110,N,,,776135,181.15,0
21,23.931,"Mount",0.128,0.031,-0.132,0.003,0.000,0.000,0,,0,,,,655613,151.93,0
22,25.053,"Mount",0.073,0.061,-0.085,0.044,0.000,0.000,0,,0,,,,629480,147.57,0
23,26.180,"Mount",-0.066,-0.026,0.071,-0.012,0.000,0.000,0,,0,,,,634072,132.26,0
24,27.360,"Mount",0.236,-0.031,-0.222,-0.081,-0.180,0.000,58,E,0,,,,696272,167.29,0
25,28.460,"Mount",0.059,-0.144,-0.023,-0.153,0.000,0.000,0,,0,,,,678967,148.36,0
26,29.584,"Mount",0.047,-0.179,-0.003,-0.185,0.000,0.000,0,,0,,,,672510,153.99,0
27,30.705,"Mount",-0.145,-0.036,0.149,-0.005,0.000,0.000,0,,0,,,,626503,151.93,0
Guiding Ends at 2021-07-14 14:05:45


#2 jerahian

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Posted 14 July 2021 - 08:34 AM

I dislike response posts which do not answer the OP's question, but I'm going to post one of those here... flowerred.gif

 

If you are looking to analyze your PHD2 logs after a night's session, are you aware of PHD2 Log Viewer?  It gives you the full breakdown of a PHD2 log file, with charts, as well as frequency analysis to help you identify periodic error motion.

 

I just wanted to make sure you were aware of the existence of this great piece of software, before you spend time writing any code yourself.  If you're looking to do something else with it, then please ignore my response.

 

CS, Ara


  • MHamburg, happylimpet and Dynan like this

#3 vland

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Posted 14 July 2021 - 05:03 PM

I dislike response posts which do not answer the OP's question, but I'm going to post one of those here... flowerred.gif

 

If you are looking to analyze your PHD2 logs after a night's session, are you aware of PHD2 Log Viewer?  It gives you the full breakdown of a PHD2 log file, with charts, as well as frequency analysis to help you identify periodic error motion.

 

I just wanted to make sure you were aware of the existence of this great piece of software, before you spend time writing any code yourself.  If you're looking to do something else with it, then please ignore my response.

 

CS, Ara

 

Thank you Jerahian, I'm aware of this software and even gave a quick look at the source code but I don't know C/C++ 

 

What I'm developing is a simple service to send me basic information from Voyager and PHD2 to my Telegram channel (on my phone)

So that I can quickly take a look at telegram to see everything is going well. smirk.gif

 

I thought it'd be nice to include an RMS value like visible in PHD2, hence my question


Edited by vland, 14 July 2021 - 05:04 PM.


#4 Der_Pit

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Posted 15 July 2021 - 11:17 AM

Well, you don't say how (which language?) you intend to program this.  So no specific hints possible.

 

Obviously, you'd have to parse the output, splitting the (comma separated) entries and picking the ones called 'dx' and 'dy' (4 and 5) then take the last N values and average the squared values, then take the root of that.  

 

A more straightforward way would be to enable the PHD2 server mode, and write some program that gets the RMS values directly from PHD2.  The Wiki might help.



#5 vland

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Posted 15 July 2021 - 04:51 PM

Well, you don't say how (which language?) you intend to program this.  So no specific hints possible.

 

Obviously, you'd have to parse the output, splitting the (comma separated) entries and picking the ones called 'dx' and 'dy' (4 and 5) then take the last N values and average the squared values, then take the root of that.  

 

A more straightforward way would be to enable the PHD2 server mode, and write some program that gets the RMS values directly from PHD2.  The Wiki might help.

 

I'll write it in C#, my question was really about the "math" behind it. I tried what you said but didn't get the same result...

also, do you know how to translate px error to arc seconds error? 

eg 0.11 > 0.46''

 

 

PS: a call to phd2 server could be an alternative, but I'd still need to process the same kind of raw data 


Edited by vland, 15 July 2021 - 04:58 PM.



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