David's Astronomy - Notes 2019-01-23 (S00650)

Focus Profiles from Session, including new HFD measurements

Profile 1: Re-focusing prior to Target 10 (GCVS Z And)

Profile 2: Re-focusing prior to Target 22 (NGC 2585, Set 2)

Profile 3: Re-focusing prior to Target 33 (GCVS SY Cnc)
My Standard autofocus method has been thrown off by two anomalous
FWHM points at either end of range. HFD method performs ok.

Profile 4: Focusing Test
Focusing Test on planned Focus Star (GSC 1310:2696)
for Crab Pulsar Project. The focus star is a double star
and cause problems for autofocusing

Issues

Where there is insufficient data to produce a good quality inner or outer line, then line should either not be drawn or the default gradient line (if
gradient is available) should be drawn as a dashed line through the largest HFD point (usually the first or last point as appropriate)
>> Extend code for drawing of inner and outer limit lines
Gradient of Inner and Outer Focus Lines (HFD) to be annotated on diagram
>> Extend code for drawing of inner and outer focus line gradients

2019-01-24

Process
As part of a strategy to protect observatory equipment during unattended operation, one potential risk is that the Battery Charge in the Shutter Drive Unit has falls to a level that the shutter can't be safely shut. Risk reduction measures involve getting digital access to the battery level (%) & voltage so that

1) the Obs.Manager routine can use these value to decide whether it is safe to open the Shutter, and

2) to make the current battery level and recent trends more readily visible to allow any issues to be flagged up

A new threaded process in AstroMain Program collects information about the health of the Shutter Drive Battery by reading values that are written to Trace logs by the ASCOM.Pulsar_Observatories_Dome driver. These are lines like

03:01:11.119 Volatile 94.1 0 0.000000 94.1 0 0 930 14866 -1 47405 -3702 2320 0

Battery Level, Voltage and Amperage and Temperature values are extracted. Data is then plotted on the ObsViewer virtula observatory plot , and also forwarded to the AstroWeather program in an ObsEnv record, which then plots the data in a graph plotting routine along with other environmental data.

Example Graph showing Shutter Battery Level
The spikes are where shutter has been open or closed

The graph is useful for showing up a falling battery level, from 97% (15.2v) down to 89% (14.7v) over 4 days. This prompts a question over whether the falling battery level can be explained by 3 observing sessions during this period (which cause a drain on the battery due to opening/closing of the shutter and prolonged periods of 4-12 hours at a time when the Induction Charger is not in a position to recharge the battery, but will be recharged over the next few days) or there is a problem with the Induction Charger, with the Battery ReCharging Process or a simply a disconnected plug.

Annotated Plot Graph showing Shutter Battery Level over a 7 day period

Checking wires/plugs showed no problem. Two of the nights have seen temperatures down to -5 degC, with daytime temperatures not rising much above 3-4degC, so this may have been a contributary factor.

Falling Battery Level. Is there absence of any evidence of recharging in the last 4 days an earlier sign of some problem
>> Contact Pulsar Observatories for comment/opinion
Falling Battery Level. Will the battery level recharge itself over the next few days
>> Monitor Battery Level over the next week.

Update (2019-01-25)

Well after a 14 hour run of flat data (indication by flat temperature values of 2.8 degC), battery recharging suddenly kicked into life around 1 am last night and has proceeded to take the battery from 89% up to 98% in 9 hours.

So it seems that the Induction Charge process is working ok, but the way it happened seems unusual. May it’s just how the system is designed to work, or it points to something specific about the Shutter firmware or something specific about my unit or the setup in my observatory.

Graph from this morning (2019-01-25) . Temp. jumps from a stuck value of 2.8 degC to 8.0 degC. Amps jumps from -1 to 12 mA.

The point where charging kicks in and latest data are shown below

The point where Recharging Kicks In is shown in the following abstract from the ascom trace file

00:53:04.278 Volatile 89.6 0 0.000000 90.0 0 1 890 14713 -1 22841 2772 5773 0
00:53:05.292 Volatile 89.6 0 0.000000 90.0 0 1 890 14713 -1 22841 2772 5773 0
00:53:06.290 Volatile 89.6 0 0.000000 90.0 0 1 890 14713 -1 22841 2772 5773 0
00:53:07.320 Volatile 89.6 0 0.000000 90.0 0 1 890 14727 12 22841 8002 2357 0
00:53:08.334 Volatile 89.6 0 0.000000 90.0 0 1 890 14727 12 22841 8002 2357 0
00:53:09.332 Volatile 89.6 0 0.000000 90.0 0 1 890 14727 12 22841 8002 2357 0

Note: Non relevant rows (Azimuth Get & Shutter Status) are removed for brevity

Temperature Data from Pulsar Dome Unit compared to other
temperature reading during S650 observing session

Temperature Data from Pulsar Dome Unit compared to the main Observatory Temperature over an 8 day period

Periods with Flat ('stuck') data .
>> Contact Pulsar Observatories technician for comment/opinion

This Web Page:

Notes - Session 650 (2019-01-23)

Last Updated :

2023-11-26

Site Owner :

David Richards

Home Page :

David's Astronomy Web Site


	Session Aims & Highlights
	- Observing Result - Night Summary Plot - Session Event Log

	Operational Issues
	- Critical Issues (0), Major Issues (3), Minor Issues (2), Continuous Improvement (5)
	Autofocussing - FWHM & HFD Profiles

	Images from 2019-01-23 >>

	Pulsar Dome - Shutter Battery Monitoring
	Pulsar Dome - Temperature Monitoring

David's Astronomy Pages
Notes - Session 650 (2019-01-23)

Session Aims & Highlights (2019-01-23)

Operational Issues (2019-01-23, S650)

Autofocussing / HFD Profiles

2019-01-24

Pulsar Dome - Shutter Drive Battery Monitoring

Pulsar Dome - Temperature Monitoring