David's Astronomy Pages Notes - Session 1324 (2025-05-10)

Notes (S1323)

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Notes (S1325A)

	Session Aims & Highlights
	- Observing Result  - Night Summary Plot  - Session Event Log
	Operational Issues
	- Critical Issues (0),  Major Issues (0),  Minor Issues (3),  Small Defects (2),  Continuous Improvement (6)
	- Figures (1)
	Images from 2025-05-10  >>
	Geomagnetic Station - Remedial Fix (2025-05-10)

Session Aims & Highlights (2025-05-10)

Main aims

1. Targets.  Acquire images of a selection of variable stars, nearby stars, comets & deep sky targets as allowed by sky conditions.

 Equipment & Software

• 12" LX200 and ST-10XME
• 80mm APO and ZWO ASI 178MC
• TheSky6, CCDSoft5, DeviceHub 7.0.3 RC3.4694, MeadeGeneric 1.3.12.522 , UPB 1.5,  Pulsar Dome Firmware 1.51 & Driver 6.3.10
• Pegasus UPB & Motor Focus, TCF-S 6.0.6
• SharpCap 3.2, PHD2  2.6.13, Siril 1.0.6, deCONZ 1.18.2, ASCOM 7.0.3 RC3
• [ DomeLink 1.0 / 1.1 - not used ]
   
• AstroMain 3.74.10,  AstroPlan 1.43.6,  AstroShCap 1.3.15, AstroGuard 1.10.6   (any new items or versions in bold)
  AstroMag 1.4.3, AstroVOE 1.15.1,  AstroSN 1.14,  AstroProtect 1.10.6,  AstroMove 1.15.12
  AstroWeather 1.27.8, AstroAllSky 3.23.5,  AstroObsCam 1.11.4 (not 1.11.5), AstroColorCam 1.2.13, AstroLaunch 1.13

Highlights

• Targets.  0/9 planned target observations were fully completed and only 1 target was partially completed.  The other 8 targets failed due to cloud/session suspension.
• CCD Camera. There were further issues with the CCDCamera freezing and images failing, with 7 red alerts being raised at 00:13 and 00:22 Issues were automatically resolved (eventually), but time was lost each time whilst RestartCCDSoft operations were carried out..
•   Dome. There was no issues opening/closing the shutter during the session. Dome closed and parked at end of session ok.

Notes

Summary Plots & Logs

Observing Plan

Observing Result

Dome & Scope Slewing Performance

Slew/Centering Performance

Guiding Performance

Sky Conditions (Locate Frames)

Night Sky Summary Plot Top axis: Sky Brightness at Zenith (in ADU/s) Lefthand axis: Local Time (hh LT). Righthand axis: Sun Altitude (degs)

Actual Weather vs Pre-Session Weather Forecast

Session Event Log

Time     Event Detail 23:49:05 Session Monitoring AutoStart monitoring for Live Session opportunity between 23:49 & 02:19 23:49:06   AutoStart Delayed Session delayed due to too few stars 00:00:48 Session AutoStarting Session autostarting (00:00) 00:01:09   CCDSoft Restarting CCDSoft being restarted (to set AutoSave No.) 00:01:36   Camera1 Connected SBIG Camera connected (Set point -15°C) 00:01:38 Session Created Session Created (Live, 2025-05-10 S01324, ImageSaveNum: 1324001) 00:01:43   Scope Switched On Telescope Power has been switched on via UPB Powerbox. 00:03:29   Services Started Observatory Services started 00:03:37 Observatory (Auto) Observatory placed in Fully-Automated Mode 00:03:39   AutoStart Delayed Session delayed due to too few stars 00:03:41 Session Pending Session pending (2025-05-10) 00:03:43 Session Initiating Session initiating (2025-05-10) 00:03:50   Camera1 Connected SBIG Camera connected (Set point -15°C) 00:03:52   Plan Requested Observing Plan requested from AstroPlan (1.43.6) 00:04:11   Plan Loaded Observing Plan loaded to queue (Plan ID: 1108) 00:04:53   Telescope Connected Telescope connected (TheSky6) 00:05:18 Session Equilibration Session ready to Open Dome 00:06:03   Dome Opened Dome opened (Opening time 45s, Zigbee 40s) 00:06:53 Session Running Session running 00:06:56   Queue Started Observing Queue started (9 targets selected) 00:06:59     Target Started (NrZen) Target started (Focus Field 14, HIP 69068) 00:07:14       Dome Unparked Dome unparked 00:11:06       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:13:47   SBIG Camera Take Image failed (Command timed-out) 00:13:48   CcdCamera Frozen CcdCamera appears to be frozen at around 00:13 in section 'SetCameraProperties / Asynchronous' 00:14:19   SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 00:14:22   CCDSoft Restarting CCDSoft being restarted (attempt to fix frozen CcdCamera) 00:14:29   SBIG Camera Reset SBIG Camera being power-cycled 00:15:23   Camera1 Connected SBIG Camera connected (Set point -15°C) 00:16:20   SBIG Camera Take Image failed (Command timed-out) 00:16:51   SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 00:17:20   SBIG Camera Take Image failed (Command timed-out) 00:17:51   SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 00:18:21   SBIG Camera Take Image failed (Command timed-out) 00:18:52   SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 00:19:21   SBIG Camera Take Image failed (Command timed-out) 00:19:52   SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 00:20:22   SBIG Camera Take Image failed (Command timed-out) 00:20:53   SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 00:21:22   SBIG Camera Take Image failed (Command timed-out) 00:21:48       Focusing Completed Foc1 AutoFocus Completed (Profile No 1, wide) 00:22:08   CCDSoft Restarting CCDSoft being restarted (attempt to fix frozen CcdCamera) 00:22:15   SBIG Camera Reset SBIG Camera being power-cycled 00:23:10   Camera1 Connected SBIG Camera connected (Set point -15°C) 00:23:21   SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 00:25:36       Focusing Completed Foc1 AutoFocus Completed (Profile No 1) 00:25:38       Focusing Started-Foc2 Foc2 Focusing Started (Secondary Scope, using ShCap) 00:27:36       Focusing Completed Foc2 AutoFocus Completed (Profile No 2, wide) 00:29:58       Focusing Completed Foc2 AutoFocus Completed (Profile No 2) 00:30:14     Target Completed (NrZen) Target completed (Focus Field 14, HIP 69068) 00:30:18     Target Started (1/9) Target started (1/9, UGC 12131 w/SN2025jyl) 00:34:52       Focusing Skipped Foc1 focusing skipped - star is too dim (TCF-S) 00:45:08     Target Completed Target partially completed (1/9, UGC 12131 w/SN2025jyl) 00:45:12     Target Started (2/9) Target started (2/9, T CrB) 00:49:25       Focusing Started-Foc1 Foc1 Focusing Started (TCF-S) 00:50:44       SoftSuspend Called Soft Suspend called due to Deteriorating Conditions (too few stars) 00:50:46   Critical Cloud Alert Critical Cloud Alert (Obs.Manager will close the Dome) 00:50:48   HardSuspend Called Hard Suspend called due to Critical Conditions (cloud) 00:50:52       Focusing Aborted Foc1 Focusing Aborted 00:50:54     Target Aborted (2/9) Target aborted (2/9, T CrB) due to cloud 00:50:56   Queue Paused Queue paused for Session Suspension 00:50:58 Session Suspending Session suspending 00:51:44   Dome Closed Dome closed (Closing time 50s, Zigbee 43s) 00:51:46 Session Suspended Session suspended 00:53:02     Target Cancelled Target cancelled (2/9, T CrB) due to cloud 01:12:32     Target Cancelled Target cancelled (3/9, AT2023fnn) due to cloud 01:24:50     Target Cancelled Target cancelled (4/9, GCVS BL Lac) due to too few stars 01:39:10     Target Cancelled Target cancelled (5/9, AT2025kej) due to cloud 01:52:00     Target Cancelled Target cancelled (6/9, AT2022bvc (CV)) due to too few stars 02:12:20     Target Cancelled Target cancelled (7/9, UGC 10058 w/SN2025gvs) due to cloud 02:34:20     Target Cancelled Target cancelled (8/9, AT2023qqq) due to too few stars 03:01:49     Target Cancelled Target cancelled (9/9, GCVS S Cyg) due to too few stars 03:01:53   Queue Completed Job Queue completed 03:01:58 Session Closing Session closing 03:02:03   Dome Closed Dome already closed (closed at 00:51, closing time 50s, zigbee 43s) 03:02:45   Dome Parked Dome parked (parking time 34s), Az: 90.0 deg 03:03:24   Telescope Parked Telescope parked (parking time 34s total) 03:03:48   Telescope State Handbox reads 'Scope parked Turn scope off.' 03:04:10   Telescope Switched Off Telescope Power has been switched off via UPB Switch. 03:05:35   Services Stopped Night Services stopped 03:05:38 Session Finishing Session Finishing started (Create Fits Summary, Transfer Files) 03:05:45     Dome (Find Park) Find Park started (Search Az 88.0 to 92.0°, Step 0.2°, Narrow) 03:06:27     Dome Find Park found (Best Park Az 90.2°) 03:06:33     Dome Dome has been synced at park position (Az 90.0°, Adjustment: -0.2°) 03:06:35   Dome Parked Dome parked 03:06:48   Dome Charging Dome is parked and re-charging Ok (15mA) 03:06:50 Session Finished Session Finished

Session Alerts & Alarms

Time     Type       Name Detail 00:13:47 Red Alert SBIG Camera Alert Take Image failed (Command timed-out) 00:14:19 Green Clear SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 00:14:20 Red Alert CcdCamera CcdCamera appears to be frozen (last cycle at 00:13:47) in section 'SetCameraProperties / Asynchronous' 00:16:20 Red Alert SBIG Camera Alert Take Image failed (Command timed-out) 00:16:51 Green Clear SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 00:17:20 Red Alert SBIG Camera Alert Take Image failed (Command timed-out) 00:17:51 Green Clear SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 00:18:21 Red Alert SBIG Camera Alert Take Image failed (Command timed-out) 00:18:52 Green Clear SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 00:19:21 Red Alert SBIG Camera Alert Take Image failed (Command timed-out) 00:19:52 Green Clear SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 00:20:22 Red Alert SBIG Camera Alert Take Image failed (Command timed-out) 00:20:53 Green Clear SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 00:21:22 Red Alert SBIG Camera Alert Take Image failed (Command timed-out) 00:23:21 Green Clear SBIG Camera Take Image command accepted (bSbigDriverException flag is reset) 03:06:48 Green Clear Dome Charging Dome is parked and re-charging Ok (15mA)

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Operational Issues (2025-05-10, S1324)

• Critical Issues (0)
• Major Issues (0)
• Minor Issues (3)
• Small Defects (2)
• Continuous Improvement (6)
  

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Critical Issues

• None

Major Issues

• None

Minor Issues

• AstroColorCam Imaging stopped running due to an exception, meaning North Cam images, videos and keogram stopped (23:24). Data products from AstroColorCam stopped being refreshed at around 23:24 due to an exception in Main Run at 23:24:45 (with the message "".  Issue was noticed in the morning and the Image Run was restarted at 07:51.  Value of '-1' is not valid for 'Value'. 'Value' should be between 'minimum' and 'maximum'. Parameter name: Value"  Code should be examined to try to find out the origin of the exception and prevent it from occuring through appropirate data checks.    At the very least such exceptions should be caught at a lower level so that it doesn't cause the Main Loop to be exited and for imaging & processing to stop.  Fixed in AstroColorCam 1.2.14.
   Fixed 2025-05-12 (AstroColorCam 1.2.14)
   
• CCD Temperature and Cooling Power stopped being available within parts of AstroMain (00:23).  There was a repeat of the issue that occurred in the last two sessions (S1322, 2025-05-08 &  S1323, 2025-05-09) and the detailed description will not be repeated here.  Tracing was added to AstroMain 3.74.10 and 3.74.11 to log the values of bRestartingCCDSoft and gCameraConnected after leaving the RestartCCDSoft() routine, and also added to TakeImageAsync to log status of various utilised flags after an Image has been successfull obtained and  iCameraOk = 0. 
  As a reminder the relevant section in RunTempMonitor() routine which writes local variables CCDTemp and CoolerPower etc requires all the following conditions to be met:
     gCameraConnected = True 
   bRestartingCCDSoft = False  
   bCcdCameraCycleIsPending = False 
   Camera1_IsAccessible()  = True
  Logs from S1324 were examined and show that following CCDSoftRestart at 00:14 following focus frame attempt 16/23 the flag states were as follows:
    gCameraConnected = True
  bRestartingCCDSoft = False
  bCcdCameraCycleIsPending = False
  Camera1_IsAccessible() = False   (* issue)
For Camera1_IsAccessible() to be True requires the all the following conditions to be met
   
  This can happen if the following conditions are met :
    (bCamera1TakingImage = False or Now() <= Camera1ExpectedStartDownloadTime)
   bRestartingCCDSoft = False
   bRunningConnectCamera = False
   gCameraConnected = True
   bCcdCameraCycleIsPending = False
   bCcdCameraReportedAsFrozen = False
Logs at 00:14 show the following flag states
    bCamera1TakingImage = True         (* probable issue)
  bRestartingCCDSoft = False
  bRunningConnectCamera = False
  gCameraConnected = True
  bCcdCameraCycleIsPending = False
  bCcdCameraReportedAsFrozen= True   (* issue) 
  Logs at 00:15 after successful frame 17/23 & successful frame 18/23 show the following flag states
     bCamera1TakingImage = False     
  bRestartingCCDSoft = False
  bRunningConnectCamera = False
  gCameraConnected = True
  bCcdCameraCycleIsPending = False
  bCcdCameraReportedAsFrozen= True   (* issue)
  Logs at 00:32 after Locate Frame 1 for UGC 12131 show the following flag states
     bCamera1TakingImage = False     
  bRestartingCCDSoft = False
  bRunningConnectCamera = False
  gCameraConnected = True
  bCcdCameraCycleIsPending = False
  bCcdCameraReportedAsFrozen= True   (* issue).
  Analysis after S1324 (2025-05-10) showed that issue occurs because Camera1_IsAccessible() is false due to  bCCDCameraReportedAsFrozen flag being unintentionally left with the value True . Fixed attempted in AstroMain 3.74.12 (2025-05-11), the bCcdCameraReportedAsFrozen flag is now reset at the end of RestartCCDSoft() and after a successful image in TakeImageAsync()
   Fixed attempted  2025-05-11 (Session, AstroMain 3.74.12)
   
• AstroPlan's ScheduleBuilder appears to have developed an issue whereby Convergence Plot does not show normal convergence/iterations. Convergence plot from the session (2025-05-10) see Fig 1a) appeared abnormal looking compared to usual Convergence (e.g S1322, 2025-05-08, see Fig 1b). Plot from the previous session S1323 (2025-05-09) was also odd. The plots from the last two sessions are noted to show a NaN value for the 'Overall' Score.  The AstroPlan executable (v1.43.6) running on the Observatory during the last two sessions is time stamped 2025-05-08 23:39, and whilst it had a minor change to add a new file to upload (ObsTempChart) there was no change to ScheduleBuilder code. Version 1.43.6 was installed on the Observatory Computer part way through session S1322 at a point which was after Observing Plan had been built using Version 1.43.5, and has been running since then.  A test plan was created on the Development computer using 1.43.5, and then repeated after installing 1.43.6.  Both had normal convergence plots.  A couple of test plan was then created on Observatory Computer which were both normal.  It is proposed to restart the AstroPlan program as a precaution.  Logs from 2025-05-08 and 2025-05-10 compared, apart from the observation that the Fitness NaN is reported right from the generation 1 there is nothing else that distinguishes them. It is proposed to restart the AstroPlan program as a precaution and to monitor things at the next session.   Schedule buiding at the start of the following session S1325 (2025-05-11) produced a nornal convergence plot. Issue is deemed to be closed.
   Closed 2025-05-12 (Session, AstroPlan)
   
• There were a series of 'SBIG Camera' red alerts during first part of the session run (00:13 - 00:22). Whilst performing NearZenith Foc1  (Wide) Focusing at the start of session, there were 7 red SBIG Camera Alerts between 00:13:47 and 00:21:22,  plus a CCDCamera red alert at 00:14:20.  Job Executor/Overseer responding by calling RestartCCDSoft at 00:14:22 and again at 00:22:08.   Problems initially began during Focus Frame 15/23 and the image was reported as failed (timed-out) and the first SBIG Camera alert was raised and a CcdCamera Frozen event was recorded at  00:13:47-48 with the  message "CcdCamera appears to be frozen at around 00:13 in section 'SetCameraProperties / Asynchronous' " and likely reported the  CCDCamera as frozen at the same time).  CCDCamera was logged as briefly resuming at 00:13:47.81 with the message "CcdCamera has resumed (cycle = 19.9s)"  but was pending again by 00:13:50  with the message "CcdCamera is Pending (3s) ". The job executor then proceeded with an attempt to take Focus Frame 16/23 at 00:13:52 ('adding fuel to the fire').  After 30s, CcdCamera was logged as frozen at 00:14:20 with the message  "CcdCamera is Frozen (33s) in section 'SetCameraProperties / Asynchronous". This triggered a call to RestartCCDSoft() in an attempt to 'fix frozen CcdCamera' .  At 00:15:23 Focus Frame 16/123 was deemed a failed .  The next 2 focus frames (17/23 & 18/23) were then successfully acquired, but Camera issues returned and Frames 18/23* to 12/23 all failed (timed--out).   In 18/23* and 19/23 , the CCDCamera was logged as Pending (up to 27s) and then briefly resumed again, before taking a pending state again.   At 00:16:17 to 20 Obs.Monitor was briefly held up with the message "Obs.Monitor resumed (cycle = 3.5s)".  There were no CcdCamera Pending states recorded during attempt to take frames 20/23 to 23/23, but each attempt led to an associated red SBIG Camera alerts. Despite these issue the Foc1 (Wide) Focusing was nevertheless completed ok on this ocassion.  In preparation for Foc1 (Standard) Focus Profile the Job Executor reported that the CCDCamera appears to be frozen and RestartCCDSoft() was called in 'an attempt to fix frozen CcdCamera'. This was successful and there were no further camera issues. Whilst Camera Issues haven't been totally resolved their impact and potential to cause Foc1 Focusing to fail is significantly reduced by the fixes in AstroMain 3.74.22. Closed after review 2025-05-31.
   Potentially fixed 2025-05-28 (Session, CCD Camera, AstroMain 3.74.22)

Small Defects

• After a frozen Camera / CCDSoft Restart focus frames were seemingly taken with Ha filter instead of C filter (00:15). Whilst performing NearZenith Foc1  (Wide) Focusing at the start of session, there were 7 red SBIG Camera Alerts between 00:13:47 and 00:21:22,  plus a CCDCamera red alert at 00:14:20.  Followin the first alert RestartCCDSoft was called and temporarily resolved the camera iss.  Focus Frames 17/23 and 18/23 were reported as having been taken with the Ha filter instead of the C filter that was being used prior to the Camera issue.  Focus Frames taken during subsequent Foc1 (Standard) Focus Profile, likewise appeared to use the Ha filter instead of the expected and normal C Filter.  Low values for Star MaxPixel and & Image MaxPixel from Focus Frame 17/23 and 18/23 are consistent with the use of a low transmission filter like the Ha Filter, rather than the much larger values seen in frames 1/23 to 14/23 that were taken with the C Filter. There is no explanation or reason for why the filter changed at this time.  The Camera reverted to using C Filter ahead of Locate Frames for Target 1/9 (UGC 12131) AstroMain should be modifed to check and if neccessary change the filter following a RestartCCDSoft operation, and before starting a new focus profile.  Underlying reason of the anomaly is not known but a fix is implented in AstroMain 3.74.12, whereby the filter position is checked as part of ConnectCamera() routine and if it is not position 0 (zerobased) (ie  1 Clear) the filter is set to 0 (zerobased) (ie 1 Clear).  The initial implementation in AstroMain 3.74.12 contained a bug that was subsequently fixed in AstroMain 3.74.13.
   Fixed in 2025-05-12 (AstroMain 3.74.13)
   
• No ObsCam images were collected during the session. This happened as AstroObsCam imaging was stopped earlier during the day by the user during separate work activity in the Observatory and it had been forgotten to turn on the imaging again after that work had finished.  Issue closed after review. It is up to user to remember to set imaging going again. One potential future automated capability could  be developed to make the program automatically restart imaging when the program recieves a 'message' from AstroMain to take a Session Starting Image.
   Closed after review (Observatory, AstroObsCam, User Awareness)

Continuous Improvement

• Modify AstroMag's Realtime StackPlots to use Solund station in place of Sumburgh Head.  Data from Sumburgh Head (or in its place Lerwick) is one of the preferred comparison stations to use in the Stackplot. However ASCII data is not available in realtime or indeed for 48 hours.  Instead of having a blank line trace in realtime (last 24 hr) stackplots or stackplots created for prior day, it is proposed to use data from the Solund (sol).
   Done 2025-05-11 (AstroMag 1.4.4)
   
• Modify AstroMag's Activity Chart to cap activity bar to top of graph area. Activity plot can produce a bar that is taller than the graph in event of large shift due to change in set up or power outage etc.  Rectange top should be capped at top of chart (grTop). Implemented in AstroMag 1.4.4.
   Done 2025-05-11 (AstroMag 1.4.4)
   
• Rationalise Create Plots buttons on AstroMag's Charts tab. Implemented in AstroMag 1.4.4. 
   Done 2025-05-11 (AstroMag 1.4.4)
   
• Extend AstroMag to produce Charts that show difference between readings from Observatory's Geomagnetic Station and those from Comparison Stations. The creation of a difference chart between Observatory's magnetometer readings and those from Comparison Stations was key to identifying a relationship between magnetometer readings produced by the SAM III box and the temperature in the Observatory where the Sam III box resides. That chart was created in Excel and and takes time and user effort which is ok for a one-off but not for repeated application.   It is proposed to automate this task in AstroMag by copying and modifying an existing Stackplot charts. The chart will be useful for tweaking the temperature coefficients used and identifying area of remaining discrepeny when using temperature corrections.  Implemented in AstroMag 1.4.5.
   Done 2025-05-11 (AstroMag 1.4.5)
   
• Modify AstroMain's ListComPorts() routine to name COM8 and COM9 Ports.  Currently in AstroMain 3.74.12 the recently added devices (the 'Ardunio/DS18B20 Temperature' and SAM III) are list in the 'COM Ports in Use' report section as COM8 and COM9 respectively but the devices are not named or described. Proposal is to modify ListComPorts routine to include device name / notes for the these two ports.  Implemented in AstroMain 3.74.13.
   Done 2025-05-11 (AstroMain 3.74.13)
   
• Rename AstroColorCam to AstroNorthCam.  Whilst AstroColorCam is a valid description as it supports imaging from the Observatory's Tapo Colour Camera,   it is harder to take in the, and isn't so descriptive as AstroNorthCam as the camera specifically collects and processes images of the north sky and the products of the program are prefixed NorthCam. The work to change the program name is quite involved and requires change to the VS project (currently AstroColorCam),  Modified Program Folder (rename to AstroNorthCam,  rename .ini file to AstroNorthCam.ini) , AstroLaunch (to launch AstroNorthCam program), AstroMove (to backup AstroNorthCam VS project and to move executable to AllSky/Weather Computer) & AstroMain (to list AstroNorthCam program version). Implemented on 2025-05-14
   Done 2025-05-14 (AstroNorthCam 1.3, AstroMove 1.16, AstroLaunch 1.3.1, AstroMain 3.74.13 )

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Geomagnetic Station -  Remedial Fix (2025-05-10)

A Geomagnetic Monitoring Station is being added to the Observatory in Spring 2025 for monitoring changes in the earth's magnetic field and to supplement and build upon the Observatory's existing Aurora monitoring that use a Black/White AllSky Camera and new NorthCam Colour Camera.

During Commissioning & Diagnositics phase it was discovered that the initial setup suffered from two significant issue (Noise & Anomalous Spiking) that require remediation.

The following notes describes the Remedial Fix that was made on 2025-05-10

Other notes  :
| Review | SAM III | Site Prep | Assembly Design | Parts Assembly | Testing | Final Assembly | Installation | Commissioning | Remedial Fix | Operation |

 

Whilst the final remedial fix was made using an LC Low Pass Filter (see below), this work came after an extended period of thought and discussion about the most appropriate fix.

First Remedial Plan (2025-04-18)
The first remedial plan formulated to solve the issues noted with Y Axis Magnetometer during Commissioning Phase involved adding a new Y Axis Sensor Assembly , which wouldn't involve digging up the existing 3 axis Sensor Assembly and would need to pull-out existing X & Y Sensors :  The plan would require

Requires
 - new FG-3+ magnetometer (£67.70 from https://robosavvy.co.uk/fgsensors-fg-3-sensor.html)
 - new fluxgate capacitors
      10 uF, 25v Tatalum Capacitor  (£ 1 + delivery)
     100 nF, 25v Ceramic Capacitor (£ 1 +delivery)
- new piping  (3 ends caps, 1 x 90 deg bend, 1 x 135 deg bend, 2 connectors - £10)
- new 15m length of Cat6 cable required (already available, but may opt for a shielded Cat6 cable given lessons / experience.

and the work would involve
  Assembly / test new magnetometer & fixture
  Part dig existing hole, install new Y Axis fixture
  Dig up trench,  thread new cablethrough corrugated pipe (if possible) or run cable beside corrugated piper


Second Remedial Plan (2025-05-01)
The propsed remediation plan as at 2025-05-01 to resolve issues discovered during Commissioning Phase were as follows:

- dig up existing setup (downhole assembly and cables)
- retrieve existing magnetometers and temperature sensor
- build new assembly,
    - incorporate wider separation between magnetometers
    - connected using S/FTP shielded cable,
    - cable shielding will be grounded at sensor assemby end, by connecting it a common drain wire
       that will be run out of the assembly and embedded in the side of hole  (shielding won't be grounded at the Observatory end)
    - continue to use standard method using unbalanced circuits
- relocate the Temperature Sensor into its our buried enclosure at the same depth as the magnetometers, but separated by some distance.
- install new assembly
- connect cables back to SAM unit in Observatory

Third (Alternate) Remedial Plan  (2025-05-02)
An alternative remedial plan was as follows:

 -dig up existing cables from hole
- retrofit TIA-422 balanced circuit system above the
   - build and install outdoor interface box at sensor end incorporating TIA-422 balanced circuit board
   - build and install circuity at SAM III end using TIA-422 balanced circuit board
   - set jumper on SAM III to 12v
   - may need to lay & use use new cabling ? (how to ground if using shielded cabling)
- potential issues with this plan.
   - the time to extra complexity at both outdoor and indoor ends of the cable
   -  the uncertainty on whether the spikes issue will be solved or not.
   - uncertainty on making the outdoor enclosure be fully water proof..

Fourth Remedial Plan (2025-05-04 - 2025-05-09)
A new plan was formulated that wouldn't require digging up the
 -conduct tests to understand the noise / cross-talk in cable wires
- conduct test to see if noise going to the SAM III unit could be removed using a LC Low-Pass Filter at the Observatory End
- if tests are positive, employ a LC Low-Pass Filter on all three cable wires at the Observatory End.
- run the system with the LC Low Pass Filters and determine if
  a) noise levels are reduced to acceptable levels and
  b) that issue with spiking /shifts in readings is eliminated.
- consider further work (if necessary) to ground all the unused cable wires at the Observatory End
- if the plan doesn't work, then other options involving digging up the sensor assembly/replacing cables come back into play.

This plan was implemented on 2025-05-10 and has proved to be broadly successful, and allowed the Geomagnetic Station to move into Operational Phase on 2025-05-13 after running without issue for 3 days.

Noise & Filter Tests & Remedial Fix (2025-05-10)
Remedial fix was finally made on 2025-05-10 after noise tests  after demonstrating the positive benefits of a LC Low Pass Filter

Noise Tests
Noise tests were conducted on 2025-05-10 to understand the amount of cross-talk / noise in the cables wires at the Observatory End.

Noise Tests Making Noise Tests on unpowered X and Y cables to show presence and amount of background noise when Z is not powered and presence and amount of noise/cross talk when Z magnetometer is powered		Examining noise on Oscilliscope Traces show signal in Y Axis due to cross-talk from the powered Z axis
Examining noise on Oscilliscope Traces show signal in X and Y Axies due to cross talk from the powered Z axis		Examining noise on Oscilliscope

Signal Filter Tests
Noise tests were followed by further tests with a LC Low Pass Filter inserted on the Z Axis.  This successfully demonstrated that a simple filter cleaned up the signal going into the SAM box and significantly reduced the noise in Z Axis readings from the SAM Box. Oscilliscope demonstrated that the filter

Signal Filtering using LC Low Pass Filter setup on breadboard using filter designed by SAM-III user John Dubois design involving a 560 pF capacitor and 6.8 mH inductor		Oscilliscope Traces Signal Input from Z Axis Magnetometer/cable run - Yellow Line Signal Out from Filter - Purple Line (Note: this is accidentally scaled x2 in the Oscilliscope window)
5 hour test run using Signal Filter on Z Axis the much lower noise in the Z Axis readings (Green line) compared to X & Y Axes (Blue & Red line) is visually clear.		Table of 10 min noise levels in X, Y & Z readings (nT, 1 S.D)
		Time      x     y      z 12:30:14, 16.6, 14.5, 1.5 12:40:15, 16.1, 13.0, 1.4 12:50:16, 16.6, 13.7, 1.9 13:00:18, 19.7, 15.0, 1.9 13:10:19, 19.5, 11.1, 1.6 13:21:11, 24.2, 16.4, 2.0 13:41:13, 27.7, 13.6, 1.7 13:51:15, 25.2, 13.9, 2.0 14:01:16, 20.5, 11.8, 1.6 14:11:18, 21.7, 13.0, 1.9 14:21:19, 23.6, 14.3, 1.3 14:31:20, 27.2, 13.4, 2.5 14:42:12, 17.2, 12.3, 1.6 14:52:13, 20.6, 12.3, 1.6 15:02:15, 23.2, 11.9, 1.0 15:12:16, 19.9,  9.8, 1.0 15:22:18, 21.6, 13.0, 0.7 15:32:19, 13.2, 10.6, 1.0 15:42:20, 19.6, 14.1, 1.0 15:53:12, 24.4, 15.1, 2.6 16:03:13, 24.7, 15.3, 1.4 16:13:15, 16.0, 13.9, 1.2 16:23:16, 19.2, 14.1, 1.3 16:33:17, 19.5, 10.0, 1.7 16:43:19, 13.6, 10.4, 1.6 16:53:20, 15.5, 10.1, 1.5 17:04:12, 16.2, 13.3, 1.1

Remedial Fix
Based on successul application of LC Low Pass Filter to demonstrably reduce noise in Z Axis signal in 3 axis setup (based on Oscilliscope graphs) and reduce 10min noise measurement as measured by AstroMag program  from 17 nT (1 SD) to an acceptable 2 nT (1 SD), a Signal Filter Circuit board was built using a LC Low Pass Filter circuit and associated terminals for each axis  (X, Y and Z) and installed in Observatory in the late afternoon on 2025-05-10.

Signal Filter Circuit Circuit constructed using the same LC low pass filter design that was tested above		Signal Filter Circuit - Annotated uses a 560 pF capacitor and 6.8 mH inductor for each of the 3 axes.

Remedial Fix Trial
Analysis of noise during the first 2 hours confirms that the Signal Filter has successfully reduced the 10min noise on all 3 axis to an acceptable low value of around 2nT (1 SD)

2025-05-10 18:24:52,  2.3,  3.0,  3.0
2025-05-10 18:34:54,  1.5,  0.9,  2.1
2025-05-10 18:45:45,  1.8,  0.9,  1.5
2025-05-10 18:55:46,  1.2,  0.7,  2.1
2025-05-10 19:05:48,  1.0,  0.3,  1.6
2025-05-10 19:15:49,  1.1,  1.2,  1.6
2025-05-10 19:25:51,  1.3,  1.0,  1.8
2025-05-10 19:35:52,  1.8,  0.5,  1.2
2025-05-10 19:45:53,  1.9,  1.2,  1.2
2025-05-10 19:56:45,  1.5,  1.7,  1.8
2025-05-10 20:11:47,  2.0,  2.9,  0.7
2025-05-10 20:21:48,  1.0,  1.5,  1.3
2025-05-10 20:31:50,  1.9,  0.6,  1.4

The setup will be run for 48 hours to see if the Signal Filter stops the previously seen spiking/shifting issue, or if the issue persists.

| Review | SAM III | Site Prep | Assembly Design | Parts Assembly | Testing | Final Assembly | Installation | Commissioning | Remedial Fix | Operation |

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