PHD logfilfortolkning

[RudiDeltager Neutron star]

Jeg er ved at analysere en logfil fra PHD 1.14 og er lidt i vildrede med hvordan man bestemmer til hvilken side DEC korrektionerne er foretaget. I logfilen er der bl.a DECDuration, et positivt antal ms der angiver pulslængde på korrektionen og DECDistance, fejl i DEC i pixels.

Kan man bare antage at når DECDistance er negativ er korrektionerne modsat vej af når DECDistance er positiv?

Edit:

Hvis ovenstående antagelse er korrekt, så ser DEC grafen således ud:

Som det ses, så bøwler jeg stadig lidt med “dec savtak effekt”.

Ovenstående er visualisering af følgende stump fra log filen:

——————————–

PHD Guide 1.14.0 — 1/3/2015 9:28:10 PM
Guiding begun
lock 1116.1 754.5, star 1116.1 754.5, Min Motion 0.15
Max RA dur 1000, Max DEC dur 1000, Star Mass delta thresh 0.50
RA angle -2.56, rate 0.0026, aggr 1.00, hyst=0.10
DEC angle -1.17, rate 0.0031, Dec mode 1, Algo 1, slopewt = 5.00
Frame,Time,dx,dy,Theta,RADuration,RADistance,DECDuration,DECDistance,StarMass,ErrorCode
1,1.659,-0.27,-0.03,-3.0,83.1,0.22,0.0,-0.08,71.04,0
2,4.510,0.18,0.69,1.3,173.5,-0.46,0.0,-0.56,67.47,0
3,7.595,-0.08,-0.27,-1.9,57.5,0.15,0.0,0.22,65.03,0
4,10.477,-0.34,0.32,2.4,0.0,0.11,0.0,-0.43,66.14,0
5,13.268,-0.79,0.82,2.3,77.0,0.20,0.0,-1.06,75.86,0
6,16.109,-1.25,0.36,2.9,299.3,0.79,268.1,-0.83,74.57,0
7,19.652,0.00,0.00,0.0,0.0,0.08,0,0,73.68,2
8,22.641,-0.42,1.21,1.9,101.9,-0.27,415.1,-1.28,82.16,0
9,26.063,-0.72,1.13,2.1,0.0,-0.04,429.3,-1.32,76.95,0
10,29.375,-0.95,2.21,2.0,141.5,-0.37,778.9,-2.40,84.76,0
11,33.376,-0.95,1.01,2.3,70.0,0.18,423.0,-1.31,63.90,0
12,36.817,0.00,0.00,0.0,0.0,0.02,0,0,76.31,2
13,39.784,-0.25,-1.67,-1.7,384.3,1.01,0.0,1.44,69.19,0
14,43.135,1.03,-1.02,-0.8,65.7,-0.17,0.0,1.35,63.78,0
15,46.018,0.80,-0.76,-0.8,93.0,-0.24,0.0,1.01,70.41,0
16,48.867,0.18,-0.77,-1.3,82.5,0.22,0.0,0.78,70.83,0
17,51.726,-0.02,-0.86,-1.6,173.8,0.46,0.0,0.78,80.17,0
18,54.936,0.00,0.00,0.0,0.0,0.05,0,0,76.06,2
19,57.952,0.00,0.00,0.0,0.0,0.00,0,0,80.34,2
20,60.938,0.40,0.46,0.8,201.5,-0.53,84.3,-0.26,86.05,0
21,64.094,-0.05,-0.34,-1.7,58.1,0.15,0.0,0.29,77.87,0
22,66.954,0.00,0.00,0.0,0.0,0.02,0,0,77.21,2
23,69.963,-0.05,-0.41,-1.7,92.5,0.24,0.0,0.36,73.16,0
24,72.839,-0.32,-0.30,-2.4,156.8,0.41,0.0,0.15,77.21,0
25,75.851,-0.64,-0.34,-2.6,262.9,0.69,0.0,0.07,82.07,0
26,79.047,0.38,-0.16,-0.4,0.0,-0.14,0.0,0.30,74.66,0
27,81.892,-0.16,0.68,1.8,86.3,-0.23,0.0,-0.68,73.07,0
28,84.782,-0.37,0.68,2.1,0.0,-0.08,0.0,-0.77,73.11,0
29,87.529,-0.60,0.35,2.6,103.3,0.27,0.0,-0.55,80.22,0
30,90.437,0.16,2.04,1.5,417.8,-1.10,587.6,-1.81,73.94,0
31,94.379,0.39,-1.24,-1.3,80.1,0.21,0.0,1.30,70.65,0
32,97.336,0.98,-1.36,-0.9,0.0,-0.05,0.0,1.64,67.78,0
33,100.163,0.86,-1.74,-1.1,77.3,0.20,0.0,1.94,68.62,0
34,103.063,0.51,-2.09,-1.3,253.7,0.67,0.0,2.12,75.21,0
35,106.250,0.95,-1.09,-0.9,0.0,-0.11,0.0,1.37,80.45,0
36,109.001,0.88,-1.29,-1.0,0.0,-0.04,0.0,1.53,76.56,0
37,111.785,1.52,-1.05,-0.6,241.3,-0.63,507.6,1.57,79.23,0
38,115.502,0.00,0.00,0.0,0.0,-0.06,0,0,69.90,2
39,118.508,0.25,-1.60,-1.4,225.6,0.59,509.6,1.57,70.37,0
40,122.296,1.26,-0.91,-0.6,170.3,-0.45,430.5,1.33,76.88,0
41,125.820,0.72,-1.04,-1.0,0.0,-0.07,401.6,1.24,71.07,0
42,129.110,1.14,-0.86,-0.6,168.8,-0.44,401.2,1.24,71.27,0
43,132.669,0.92,-0.59,-0.6,169.3,-0.44,292.6,0.90,84.32,0
44,136.041,0.63,-1.40,-1.1,64.5,0.17,496.4,1.53,78.70,0
45,139.547,1.14,-0.65,-0.5,200.1,-0.53,338.1,1.04,69.87,0
46,143.239,0.95,-1.06,-0.8,94.1,-0.25,436.5,1.35,68.77,0
47,146.684,0.71,-0.72,-0.8,79.2,-0.21,304.1,0.94,84.77,0
48,149.983,0.91,-0.64,-0.6,149.9,-0.39,305.3,0.94,75.54,0
49,153.397,0.47,-1.13,-1.2,60.4,0.16,396.4,1.22,71.32,0
50,156.844,0.48,-0.65,-0.9,0.0,-0.03,254.2,0.78,64.05,0
51,159.982,0.47,-0.48,-0.8,0.0,-0.12,201.8,0.62,73.39,0
52,163.020,0.00,0.00,0.0,0.0,-0.01,0,0,83.68,2
53,166.006,0.58,-0.43,-0.6,86.9,-0.23,201.4,0.62,85.11,0
54,169.081,0.34,-0.75,-1.1,0.0,0.09,267.5,0.83,67.61,0
55,172.292,0.72,-0.80,-0.8,0.0,-0.14,329.5,1.02,70.21,0
56,175.591,-0.14,-0.67,-1.8,161.1,0.42,181.3,0.56,77.58,0
57,178.971,0.49,-0.18,-0.4,88.8,-0.23,116.7,0.36,70.41,0
58,182.112,-0.10,-0.08,-2.5,0.0,0.10,0.0,0.03,69.41,0
59,184.893,-0.42,0.63,2.2,0.0,0.02,0.0,-0.74,80.16,0
60,187.699,-0.52,-0.10,-3.0,167.3,0.44,0.0,-0.11,71.24,0
61,190.738,0.00,0.00,0.0,0.0,0.04,0,0,72.60,2
62,193.706,0.00,0.00,0.0,0.0,0.00,0,0,70.27,2
63,196.711,-1.38,-0.74,-2.7,534.4,1.40,0.0,0.13,78.43,0
64,200.139,-0.90,0.13,3.0,287.4,0.75,0.0,-0.47,66.77,0
65,203.322,0.00,0.00,0.0,0.0,0.08,0,0,72.09,2
66,206.374,-0.41,1.36,1.9,135.5,-0.36,0.0,-1.41,75.21,0
67,209.445,-0.06,1.32,1.6,242.6,-0.64,0.0,-1.24,74.01,0
68,212.582,-0.86,1.38,2.1,0.0,-0.09,521.3,-1.61,72.04,0
69,216.003,-0.50,1.61,1.9,160.6,-0.42,544.1,-1.68,76.06,0
70,219.646,-1.11,2.21,2.0,111.3,-0.29,801.6,-2.47,96.84,0
71,223.586,-0.71,2.33,1.9,242.7,-0.64,783.7,-2.42,79.45,0
72,227.664,-1.70,1.65,2.4,155.0,0.41,706.6,-2.18,73.29,0
73,231.541,-1.30,2.75,2.0,124.6,-0.33,984.9,-3.04,80.74,0
74,235.640,-1.76,1.98,2.3,123.8,0.33,813.5,-2.51,66.93,0
75,239.648,-1.35,2.98,2.0,158.5,-0.42,1000.0,-3.27,79.79,0
76,243.810,-1.22,1.75,2.2,0.0,0.02,676.0,-2.09,79.01,0
77,247.456,0.00,0.00,0.0,0.0,0.00,0,0,83.15,2
78,250.477,1.00,-1.49,-1.0,0.0,-0.02,0.0,1.76,79.80,0
79,253.295,0.76,-1.25,-1.0,0.0,0.04,0.0,1.45,72.01,0
80,256.067,0.71,-2.07,-1.2,184.5,0.48,0.0,2.19,68.44,0
81,259.089,1.24,-1.58,-0.9,0.0,-0.11,0.0,1.94,86.29,0
82,261.875,1.82,-1.20,-0.6,302.7,-0.79,0.0,1.82,66.93,0
83,265.090,1.32,-0.28,-0.2,357.3,-0.94,0.0,0.77,84.53,0
84,268.385,-0.51,-1.63,-1.9,417.4,1.10,0.0,1.30,64.98,0
85,271.558,0.59,-1.80,-1.3,209.1,0.55,613.0,1.89,72.16,0
86,275.317,1.06,-0.62,-0.5,167.0,-0.44,321.4,0.99,64.54,0
87,278.761,0.00,0.00,0.0,0.0,-0.04,0,0,76.80,2
88,281.767,1.05,-0.36,-0.3,234.0,-0.61,241.9,0.75,63.05,0
89,285.279,0.23,-1.41,-1.4,175.6,0.46,449.5,1.39,78.92,0
90,288.915,1.07,-0.02,-0.0,286.7,-0.75,142.2,0.44,72.07,0
91,292.343,0.99,-0.81,-0.7,161.3,-0.42,366.1,1.13,59.91,0
92,295.931,0.78,-0.76,-0.8,98.1,-0.26,325.5,1.00,69.61,0
93,299.274,0.98,-0.54,-0.5,190.1,-0.50,286.4,0.88,66.71,0
94,302.685,0.75,-0.22,-0.3,193.6,-0.51,161.4,0.50,61.76,0
95,306.017,1.11,0.40,0.3,413.1,-1.08,0.0,0.06,71.28,0
96,309.380,0.29,-1.22,-1.3,104.4,0.27,398.8,1.23,75.80,0
97,312.843,0.00,0.00,0.0,0.0,0.03,0,0,75.56,2
98,315.870,-0.79,-0.45,-2.6,310.4,0.81,0.0,0.10,70.97,0
99,319.006,-0.25,-0.21,-2.4,141.2,0.37,0.0,0.09,68.18,0
100,322.064,0.36,-0.48,-0.9,0.0,0.00,190.2,0.59,76.01,0
101,325.194,0.46,0.63,0.9,249.9,-0.66,0.0,-0.40,83.72,0
102,328.318,-0.72,0.44,2.6,100.3,0.26,0.0,-0.69,62.11,0
103,331.203,0.11,-0.68,-1.4,104.7,0.27,216.8,0.67,79.93,0
104,334.402,0.29,-0.07,-0.3,58.7,-0.15,58.8,0.18,65.69,0
105,337.458,-0.34,0.94,1.9,84.0,-0.22,0.0,-1.00,76.68,0
106,340.343,-0.38,1.09,1.9,103.3,-0.27,0.0,-1.16,82.81,0
107,343.287,-0.49,0.98,2.0,0.0,-0.14,0.0,-1.10,75.80,0
108,346.065,-0.43,1.05,2.0,76.9,-0.20,367.7,-1.13,73.22,0
109,349.532,-0.79,1.68,2.0,94.3,-0.25,600.4,-1.85,75.22,0
110,353.197,-1.31,0.92,2.5,195.6,0.51,440.2,-1.36,77.57,0
111,356.847,-0.72,0.92,2.2,0.0,0.14,366.7,-1.13,70.87,0
112,360.180,-0.24,1.62,1.7,228.0,-0.60,514.2,-1.59,69.32,0
113,363.972,-0.87,1.93,2.0,134.5,-0.35,685.4,-2.11,82.02,0
114,367.913,-0.55,2.43,1.8,309.1,-0.81,793.7,-2.45,81.27,0
115,371.992,-2.27,1.25,2.6,387.2,1.02,662.1,-2.04,82.87,0
116,376.069,-0.58,1.01,2.1,0.0,0.04,373.8,-1.15,68.49,0
117,379.430,0.28,-0.34,-0.9,0.0,-0.04,0.0,0.43,70.46,0
118,382.268,0.76,-0.70,-0.7,90.2,-0.24,0.0,0.94,81.87,0
119,385.178,0.36,-0.98,-1.2,71.6,0.19,0.0,1.04,89.03,0
120,388.053,0.38,-0.97,-1.2,79.6,0.21,0.0,1.04,78.10,0
121,390.976,0.50,-0.63,-0.9,0.0,-0.04,0.0,0.78,76.52,0
122,393.760,0.93,-0.15,-0.2,239.5,-0.63,0.0,0.50,74.78,0
123,396.969,0.47,-1.00,-1.1,0.0,0.07,0.0,1.11,84.63,0
124,399.791,0.78,-0.99,-0.9,0.0,-0.10,393.7,1.21,65.70,0
125,403.157,0.34,-1.00,-1.2,84.3,0.22,341.0,1.05,77.51,0
126,406.616,0.66,-0.69,-0.8,0.0,-0.13,290.5,0.90,71.11,0
127,409.775,0.33,-0.27,-0.7,0.0,-0.13,122.0,0.38,78.05,
0
128,412.959,0.00,0.00,0.0,0.0,-0.01,0,0,65.62,2
129,415.995,0.64,-0.00,-0.0,183.5,-0.48,82.2,0.25,74.30,0
130,419.128,0.33,-0.60,-1.1,0.0,0.00,221.0,0.68,55.15,0
131,422.337,0.17,0.59,1.3,160.1,-0.42,0.0,-0.48,76.38,0
132,425.386,0.00,0.00,0.0,0.0,-0.04,0,0,72.75,2
133,428.414,0.47,0.68,1.0,264.1,-0.69,0.0,-0.44,72.51,0
——————————–

Billedet havde som forventet aflange stjerner i DEC retningen.

Efterhånden er jeg ved at tro at det simpelthen er monteringen det er galt med. Det er måske tandhjul og snekker i motor/grae/montering der er klar til udskiftning?

Edit-edit:

Det skal lige tilføjes, at grundet Månen var næsten fuld, kombineret med en lidt diset atmosfære, så sloges PHD indimellem med at signal/støj forholdet var for lavt, ind imellem under 2 og aldrig over 3! Men på den anden side, så kørte ra guidingen fint.

Edit-edit-edit:

Efter at have siddet og kikket lidt på grafen, så kan noget tyde på at der er en enorm backlash i dec systemet?

rudibr2015-01-04 18:19:40

/Rudi B. Rasmussen

[RudiDeltager Neutron star]

Fra hestens egen mund:

————-

My guess is that you’re well balanced in Dec and rocking in the gears a bit. You’re using the “resist switch” Dec guiding mode that assumes your error is all going to be in one direction. Polar misalignment will lead to a drift that is unidirectional. This mode will only give Dec guide commands if they’re in the direction of drift it thinks is going on. This is done to keep you on one side of the worm.

If you have very little real drift but rock in the gears a bit, PHD can easily think the drift has reversed or that it’s guess was incorrect, switching the allowed direction of movement. But, it takes some number of samples for this to occur and you can end up with the sawtooth.

Try either unbalancing in Dec a bit (so you can’t rock so easily) or changing to the “lowpass” algorithm (or both).

Craig

————-

Jeg prøver Craig’s forslag

/Rudi B. Rasmussen

[edbbobDeltager Super Nova]

@Rudi

Hvis din montering er alignet nogenlunde fornuftigt kan du være heldig at du kan guide helt uden DEC. Det er mest RA som jo konstant drives frem af mekanikken (og dermed har en periodisk fejl) som man guider.

Det med at have en svag ubalance (man står altid og tænker hvor meget? Tag rigeligt!) er heller ikke så tosset.

Overordnet kan man sige at den som virkelig forstår guiding, har et hoved som er skruet ufatteligt godt på. Det er indviklet, og der er mange faktorer som spiller ind. Personligt synes jeg mere det er held end forstand, når mine stjerner ikke er aflange.

Vh

Morten

[RudiDeltager Neutron star]

Tak for svar Morten. Nu har jeg jo lige bestilt EQ5 Pro opgradering, dvs stepper motore og GOTO. Og efter at have læst manualen igennem er jeg meget fortrøstningsfuld, især kapitlet der beskriver pol align funktionen hvor man finjusterer polalignment på en eller flere stjerner glæder jeg mig til at få adgang til. Ligeledes syntes jeg at backlash kompensationen også ser smart ud, jeg skal dog lige forstå denne funktion lidt bedre inden jeg bruger den (så vidt jeg forstår, så er det simpelthen bare hvor langt i siderisk tid, målt i grader, et objekt står stille når man har slewet mod øst og stoppet. Kan ikke lige se hvordan det virker på dekl.?)

I øvrigt havde jeg misforstået “resist switch” funktionen i PHD, og som Craig skrev til mig, så er det jo nok en kombination af backlash og resist switch der har drillet mig.

/Rudi B. Rasmussen

[Torben TaustrupAdmin Neutron star]

Jeg er enig med Morten. Hvis opstillingen er nøjagtigt polopstillet, så behøver

man ikke at lave korrektioner på deklinationen.

Det ser ud til, at din deklination overkorrigerer, for en korrektion skulle

gerne flytte stregen op/ned på 0-linjen.

Selvom vores opstilling er perfekt polopstillet, så vil deklinationen lave

korrektioner pga. lufturoen. I princippet behøver vi ikke at guide på deklina-

tionsaksen, men da der altid vil være variationer på R.A., så vil de to tilsam-

en give pænere stjerner

Det er jo egentlig lidt underligt, at vores deklination kører mere præcist end

R.A. – men vi er nok ovre i diskussionen om massen der skal flyttes kontra den

kraft der er til rådighed.

mvh

Torben

TOC Observatory - "http://tocobs.org -14.5″ – f:4,2 Newt - Atik383 - ZWO2600-mono – SXV H9 - QHY8L-color - SkyWatcher 80 mm ED refraktor - 60 mm F:6 apocromat - TAL Apolar 125 f : 7,5.

[RudiDeltager Neutron star]

Torben Taustrup wrote: Jeg er enig med Morten. Hvis opstillingen er nøjagtigt polopstillet, så behøver
man ikke at lave korrektioner på deklinationen.

Det kan vi forhåbentligt alle blive enige om (Men rent principelt kræver det jo også at mountet står nøjagtig i vatter, i hvert fald i ø/v retning)

Jeg håber at det hjælper at opgradere monteringen til de mere præcise step motore samt goto kontrol. Med Synscan hånd kontrollen kan man jo checke pol alignment og efterjustere på en stjerne samt kompensere for backlash.

Nu skal jeg have kittet hjem fra Henrik (Lyra), montere det, og så ellers ud i alle de klare nætter vi efterhånden har til gode. Så starter jeg helt forfra og skal lære goto setuppet at kende, først visuelt, dernæst foto uden guiding for at se hvad der er muligt med de nye motore ifht de gamle og først da vil jeg starte op med auto guiding igen – og ihhh hvor jeg dog glæder mig

/Rudi B. Rasmussen

[Torben TaustrupAdmin Neutron star]

Jeg skal nok lige tilføje, at selvom opstillingen er korrekt polopstillet, så

vil der pga. atmosfærens varierende afbøjning ved forskellige højder over

horisonten ske en gradvis feltglidning i deklinationsretningen. Dette forhold

kan retfærdiggøre guiding på deklinationen.

mvh

TOrben

TOC Observatory - "http://tocobs.org -14.5″ – f:4,2 Newt - Atik383 - ZWO2600-mono – SXV H9 - QHY8L-color - SkyWatcher 80 mm ED refraktor - 60 mm F:6 apocromat - TAL Apolar 125 f : 7,5.

[RudiDeltager Neutron star]

Ja Torben, utrolig mange faktore spiller ind, og atmosfærisk refraktion kender jeg jo alt til som gammel styrmand fra sekstanternes tid. Og det smarte ved autoguiding er jo at det bl.a automatisk korrigerer for dette, hvis guide teleskopet ellers ser i nogenlunde samme retning som hoved teleskopet.

/Rudi B. Rasmussen

[Forfatter]

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