Slew to position error after platesolving (e.g. meridian flip or sequence start)

[Ruediger]

[yes ] Is the issue reproducible?
[x ] Are you running the latest version?
[x ] Are all prerequisites that are mentioned inside the manual met?

Description

After a Meridian Flip there is an position offset generated though the mount points to the right possition.

After the flip is executed the mount points to the correct position. Then it takes a plates solve image, solves and corrects the mount to a wrong position. It looks like, that the mount is sent to the J2000 coordinates of the solve and not to the JNOW coordinates. This also happens in sequence when slewing to target is activated.

This happens in all flips and slews to targets.

Steps to Reproduce

• Enable flip and “Recenter after Flip”
• Execute Flip
• after solving the correct position the mount slews to an offset (approx. 2')

Expected behaviour

stay on or move to correct position

Actual behaviour

there is an offset generated

Log attached

[DeepSky]

I use a Meade Lx200 GPS and I have the same issue. Slew is pretty good, but Reslew To Taget point the scope every time some arc minute in RA out from the correct position.

1. The scope is well alligned and ready to observe.
2. Select a target in sky atlas Form.
3. Press the Slew button in the same Form.
4. Telescope move and Target is placed very near the center of the image.
5. Do a Plate Solving and Recenter.
6. An image is taken and solved, the scope is moved some arc minuts to West, placing the target away from center of the image, another image is taken and solved and process end with success. (?).

I hope this help.

N.I.N.A. ver. 1.10 HF1

[Jim Waters]

Same issue here too with my Losmandy GM811G.

[DeepSky]

I am attaching a short ASCOM log (commented) illustrating the problem I encounter in the CENTER routine. As you can see, the telescope is positioned on the target, is synchronized on the coordinates of the image taken and is repositioned on coordinates that do not correspond to those of the target. The next CENTER rutine will confirm the position as correct a few minutes away from the target. Unfortunately, I do not have the corresponding NINA log available.
Hope this helps.

/Slew to target.
19:21:56.622: Telescope - Commands: SlewToCoordinates
RA 06:42:08
Dec 009° 52' 25": (slew started)
19:22:12.895: Telescope - Commands: SlewToCoordinates: (slew complete)

/Sync on solved position.
19:23:15.631: Telescope - Commands: SlewToCoordinates
RA 06:42:10
Dec 009° 51' 56":
19:23:21.211: Telescope - Commands: SyncToCoordinates: (done)

/Reslew to target. As you can see the coordinate differs from those of the target.
19:23:23.579: Telescope - Commands: SlewToCoordinates
RA 06:42:22
Dec 009° 52' 22": (slew started)
19:23:39.082: Telescope - Commands: SlewToCoordinates: (slew complete)

[DeepSky]

Continuing to have pointing problems with the MEADE LX200GPS, I ran a series of tests using NINA's camera simulator and the MEADE real telescope.
As can be seen from the attached logs, although the telescope is correctly synchronized, in the N.I.N.A. report "failed silently", although in the NINA log the destination coordinates have apparently not been changed, the coordinates actually sent to ASCOM are different.

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ASCOM log (Epoch: Jnow)

10:55:34.418: Telescope - Commands: SlewToCoordinates
RA 21:30:57
Dec 012° 15' 25": (slew started)
10:55:44.927: Telescope - Commands: SlewToCoordinates: (slew complete)
10:56:35.316: Telescope - Commands: SlewToCoordinates
RA 21:31:06
Dec 012° 15' 30":
10:56:40.926: Telescope - Commands: SyncToCoordinates: (done)
10:56:50.978: Telescope - Commands: SlewToCoordinates
RA 21:30:55
Dec 012° 15' 37": (slew started)
10:57:02.583: Telescope - Commands: SlewToCoordinates: (slew complete)

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N.I.N.A. log (Epoch: J2000)

[2021-02-09T10:56:28.7412] [TRACE] [MemberName] Solve
[2021-02-09T10:56:28.7412] [TRACE] [FileName] E:\Projects\nina\NINA\PlateSolving\ImageSolver.cs
[2021-02-09T10:56:28.7412] [TRACE] [Message] Solving with parameters:
FocalLength: 631
PixelSize: 3
SearchRadius: 30
Regions: 500
DownSampleFactor: 2
MaxObjects: 500
Reference Coordinates RA: 21:29:59 Dec: 12° 10' 09" Epoch: J2000

[2021-02-09T10:56:29.7256] [INFO] [MemberName] FinalizeSave
[2021-02-09T10:56:29.7256] [INFO] [FileName] E:\Projects\nina\NINA\Model\ImageData\ImageData.cs
[2021-02-09T10:56:29.7256] [INFO] [Message] Saving image at C:\Users\Carlo\AppData\Local\NINA\PlateSolver\mgmiwqeu.us4.fits

[2021-02-09T10:56:29.7286] [TRACE] [MemberName] SaveToDisk
[2021-02-09T10:56:29.7286] [TRACE] [FileName] E:\Projects\nina\NINA\Model\ImageData\ImageData.cs
[2021-02-09T10:56:29.7286] [TRACE] [Message] Start: 09.02.2021 09:56:28.746; Stopped: 09.02.2021 09:56:29.728; Elapsed: 00:00:00.9817273

[2021-02-09T10:56:29.7326] [DEBUG] [MemberName] StartCLI
[2021-02-09T10:56:29.7326] [DEBUG] [FileName] E:\Projects\nina\NINA\PlateSolving\Solvers\CLISolver.cs
[2021-02-09T10:56:29.7326] [DEBUG] [Message] Starting process 'C:\Program Files\astap\astap.exe' with args '-f "C:\Users\Carlo\AppData\Local\NINA\PlateSolver\mgmiwqeu.us4.fits" -fov 0.960771 -z 2 -s 500 -r 30 -ra 21.499733 -spd 102.169109'

[2021-02-09T10:56:35.2742] [DEBUG] [MemberName] Center
[2021-02-09T10:56:35.2742] [DEBUG] [FileName] E:\Projects\nina\NINA\PlateSolving\CenteringSolver.cs
[2021-02-09T10:56:35.2742] [DEBUG] [Message] Centering Solver - Scope Position: RA: 21:29:58; Dec: 12° 10' 08"; Epoch: J2000; Centering Coordinates: RA: 21:29:59; Dec: 12° 10' 09"; Epoch: J2000; Solve Result: RA: 21:30:07; Dec: 12° 10' 06"; Epoch: J2000; Separation RA: -00:00:09; Dec: 00° 00' 02"; Distance: 0.0351558511183264; Bearing: -90.9592852599004

[2021-02-09T10:56:50.9495] [DEBUG] [MemberName] Center
[2021-02-09T10:56:50.9495] [DEBUG] [FileName] E:\Projects\nina\NINA\PlateSolving\CenteringSolver.cs
[2021-02-09T10:56:50.9495] [DEBUG] [Message] Sync failed silently - calculating offset instead to compensate. Original: RA: 21:30:04; Dec: 12° 10' 10"; Epoch: J2000; Solved: RA: 21:30:07; Dec: 12° 10' 06"; Epoch: J2000; Offset: RA: -00:00:03; Dec: 00° 00' 04"; Distance: 0.0107784036935298; Bearing: -95.9368986390169

[2021-02-09T10:56:50.9525] [TRACE] [MemberName] Center
[2021-02-09T10:56:50.9525] [TRACE] [FileName] E:\Projects\nina\NINA\PlateSolving\CenteringSolver.cs
[2021-02-09T10:56:50.9525] [TRACE] [Message] Slewing to target after sync. Target coordinates RA: 21:29:59 Dec: 12° 10' 09" Epoch: J2000

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[Stefan B]

Hi,

when a sync is rejected N.I.N.A. will shift the coordinates instead to reach the correct target position.

As the log indicates, the sync call to ASCOM returns successful, but the coordinates after the sync are still misaligned and then N.I.N.A. proceeds to shift the coordinates, as it thinks that it is not synced correctly. Looks to me that the driver is not updating the RA/Dec immediately after sync which leads to this scenario.

[Ruediger]

Hi,

in my case all Snycs are disabled. As well in the NINA options (“No Sync”=”ON”), as also in the ASCOM driver.

‌

[Stefan B]

When sync is disabled, NINA will also calculate offset coordinates to reach the destination. Otherwise it would be impossible to center a target.

[Ruediger]

Clear. Just wanted to add this information, in order to identify the root cause of the problem. Maybe something is going wrong in this use case when calculating the offset. I suppose that most of the users have their mounts set to accept Syncs. So this problem may occur rather rarely.

[DeepSky]

Surely the firmware of the Meade LX200 does not shine for it’s speed, but N.I.N.A. must wait for the response from the telescope driver.

Otherwise the telescope is correctly synchronized, and the correction movements are wrong.

[Stefan B]

N.I.N.A. asks the ASCOM driver for the current scope coordinates after the sync. There is no way of knowing for the application if the driver is just slow with the updates, as it can just query the ascom driver for the current telescope coordinates and that’s what the driver responds.

[Dale Ghent]

By my count, there are at least 4 different ASCOM drivers of various states of maintenance that support the LX200 systems in some way. Meade does not make their own mount drivers, so there have been many 3rd party attempts over the years. Are both of you using the same ASCOM driver? Have you tried a different ASCOM driver for the LX200 to see if the problem persists?

[Ruediger]

I am using a 10 Micron mount and the original 10 Micron ASCOM driver.

[DeepSky]

I use the latest firmware for LX200GPS on the ASCOM site which is ver.5.0.

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[Stefan B]

Most likely this issue is not there in 1.11 anymore. If it is still there please reopen.

[Ruediger]

Did not happen to me again in latest nightly. I think it is fixed. Thx!

Rüdiger