Hi Guys,
Trying to make some sense of a PHD log from my last guising session.
It's a 3 hour log which did include some wind gusts guiding a 12.5" f/5 with an OAG, Lodestar and Canon 400D.
I was able to get 5 min shots with round stars, with about 70% of frames usable.
Trying to improve the "brain" set up using this data in PHD.
One obvious thing is that I was 11 arc minutes away from the SCP in terms of polar alignment - is this meant to be in DEC, RA, or both?
Any commentary people can provide would be great.
Thanks in advance,
John K.
Analysis covers 01:15 AM to 04:15 AM Guiding errors
Guider px
Arcsecs
Image px
RA peak error
7.90
8.46
11.36
RA RMS error
0.64
0.68
0.92
DEC peak error
9.61
10.29
13.82
DEC RMS error
1.12
1.20
1.62
Combined peak error
11.25
12.04
16.18
Combined RMS error
1.29
1.38
1.86
Correction drive analysis
RA
DEC
Frames with correction
49.0%
43.9%
Corrections at max
0.0%
100.0%
Average percent of max corr.
18.3%
100.0%
Periodic errors in RA
Top 5 periodic components in RA error, showing period & amplitude. Amplitude is relative to the DC offset.
Guider px
Arcsecs
Image px
DC offset
0.15
0.16
0.22
108.3 minutes
0.15
0.16
0.21
24.17 seconds
0.13
0.14
0.19
21.7 minutes
0.11
0.12
0.16
1.8 minutes
0.11
0.12
0.16
2.2 minutes
0.11
0.11
0.15
Drift estimate
Guider px
Arcsecs
Image px
DEC drift / minute
1.46
1.56
2.09
Std error of drift mean
0.55
0.59
0.79
Estimated polar-alignment error: 11.24 arcmins, based on specified guide-star declination of -58º. Experimental estimate for non-drift-check events. Field rotation
Estimated maximum field-rotation per minute at farthest edge of imaging field for various guider-to-imager alignment offsets in multiples of imager FOV. Guidestar-to-edge angles in arcmins.
John,
According to the PHD help file the polar alignment is an "estimate"
You need then to use the drift align tab feature to get corrections in Azimuth and Altitude.
