42 replies to this topic

[zbadger]

Xavier Jubier's site 

http://xjubier.free..../solar_eclipses

calculates timing and latitude and longitude for the entire eclipse path.  Very much appreciate his nationwide utlity. 

 

That being said, I picked a random spot and loaded all his info exactly into Eclipse Orchestrator (EO).

 

29° 45' 56.94" N   <—>   29.76582°      4m 26.1s (total solar eclipse)
99° 33' 35.00" W   <—>   -99.55972°
Start of total eclipse (C2) :  2024/04/08 18:30:56.4

 

Of course, very crucial for automated imaging is knowledge of the timing of second contact.  I put in all his location information exactly into EO and EO's second contact time was 18:30:52.0 - 4.4 seconds EARLIER than Xaviers calculation.  I know it is important to bracket but when one wants to shift from Bailys Beads to Chromoshere and Prominences, one could miss one or the other very easily over a 4 second span. 

 

Solutions - suggestions - thoughts as to how to correct one way or another for such a discrepancy?

 

PS - I have Refraction Correction and Limb Profile Correction checked in EO if that matters at all??

 

[starrycanuck]

There is a solar size option as well in EO which makes a difference as well. Not at my PC right now but it is in one of the configuration menus.

[agavephoto]

Do both apps have the same elevation set for the location?

[timelapser]

How old is your version of EO?  Eclipse timings depend on the Delta t parameter, which is hard to predict.  Several years ago people estimated it would be around 74 seconds in 2024, but it's actually around 69.  Jubier's map uses 69.2.

 

If it's an older version of EO that could explain the 4 or so second offset.  And a larger Delta t would give an earlier C2.

[starrycanuck]

There is a solar size option as well in EO which makes a difference as well. Not at my PC right now but it is in one of the configuration menus.

Ok found the menu in EO, Setup/Solar Radius allows you to select the traditional radius 959.63" or the recommended newer, more accurate radius of 959.98".

 

Additionally, ensure that you have LRO/Kaguya selected as the Limb Profile source.

 

Sadly, now that I compare the times I'm getting ... EO is forecasting C2 20s (!!) later than Xavier's map (0s limb correction at the location I'm using). Never noticed that before ... will need some investigation.

[starrycanuck]

Ca

 

How old is your version of EO?  Eclipse timings depend on the Delta t parameter, which is hard to predict.  Several years ago people estimated it would be around 74 seconds in 2024, but it's actually around 69.  Jubier's map uses 69.2.

 

If it's an older version of EO that could explain the 4 or so second offset.  And a larger Delta t would give an earlier C2.

Is this a parameter that we can edit or does it require EO update? I'm using the 3.8 2019 version of EO.

[timelapser]

Is this a parameter that we can edit or does it require EO update? I'm using the 3.8 2019 version of EO.

I don't know.  And I don't know if you can find what value EO uses.  But on this page:

https://eclipse2024.org/DeltaT.html

you can see a history of Delta t estimates and in 2019 they estimated 74 seconds.

 

If you can't set it manually you can always add 4 or 5 seconds in your head.

[AsleepAtTheScope]

I tried the same comparison for my expected position and there are differences for all contacts and the difference varies from 0.5s to 2.2s. I found that setting the solar radius to 959.63 (first choice in EO, also not the one recommended by Jubier) and unsetting Limb Profile Correction made C2, mid eclipse and C3 times in EO all 0.1s earlier than the website times. The position and altitude values were the same and I'm running EO 3.9.1.

Edited by AsleepAtTheScope, 15 March 2024 - 10:20 AM.

[sbsbbugsy]

Is there any other data source(s) that we can compare these to? Is one off or both?

Edited by sbsbbugsy, 15 March 2024 - 11:05 AM.

[timelapser]

Eclipse guru Espenak's site: https://eclipsewise....pr08Tgmapx.html

and gmiller123456's map: https://www.celestia...wer/viewer.html

both agree within a second with Jubier's map where I've tested them.  They both use Delta t around 69s.

[KevinMerchant]

I am using EO v3.9.1 (build April 18, 2023), which has the default Solar Radius set to 959.98" and Limb Profile Data Source default set to LRO/Kaguya. I know that this version is listed as beta in one place on the Moonglow web site, but it is listed as released in another place. I have been using it now for more than two months with no issues.

 

If you go into Setup >> Choose Events >> Show Besselians..., EO will open a file in Notepad called besselians.dat. Here you will find parameters for eclipse events.

 

The entry for April 8th shows a delta T of 69.14. The latest delta T estimate I have seen is 69.18. I am not certain where a more reliable value can be found.

 

Unfortunately, EO does not give you a way to directly change the delta T, that I have found. The problem with editing the besselians.dat file in Notepad is that you do not have permissions to save it where it is located (Program Files (x86) >Eclipse Orchestrator>Elements). At least, this has been my experience. You can edit the value, save the file in some other location and then copy it into the same spot. Be sure to make a backup copy in case something goes wrong.

 

I did do the above, but I am not seeing any difference in times as I would have expected. I don't know how much sensitivity to expect.

 

My understanding from Fred's presentation to the Kalamazoo Astronomical Society was that he intended to have a build ready in February, with an updated delta T along with more eclipse events at a minimum. So far, no new build has appeared. Still hoping he can get a new build done. 

[OJN]

The Besselian elements are stored in the program folder of EO in the subfolder Elements, in the file Besselian.dat

Using data from https://eclipse.gsfc...hp?Ecl=20240408 (seems to be updated from time to time) and changing DeltaT from 74.0s to Jubier's 69.1s I get sufficiently good agreement by changing the entry to:

 

2024 Apr 8 Total (Espenak)
2024 4 8 15.0 18.0 21.0 69.1 37
0 0/0 TOTAL
-0.3182440 0.2197640 7.5862002 0.5358140 -0.0102720 89.591217
0.5117116 0.2709589 0.0148440 0.0000618 0.0000615 15.004080
0.0000326 -0.0000595 -0.0000020 -0.0000128 -0.0000127 0.000000
-0.0000084 -0.0000047 0.0000000 0.0000000 0.0000000 0.000000
0.0046683 0.0046450

(no guarantee)

Edited by OJN, 15 March 2024 - 01:34 PM.

[timelapser]

The entry for April 8th shows a delta T of 69.14. The latest delta T estimate I have seen is 69.18. I am not certain where a more reliable value can be found.

I think the best source for the latest Delta t values is https://maia.usno.na...products/deltaT

 

The latest value there (for January) is 69.18s.  It's unlikely to change much by April and using a value of 69.14s only changes your timings by 0.04s, so totally negligible.  Using instead the older value of around 74s would start to make a noticable difference.

[KevinMerchant]

The Besselian elements are stored in the program folder of EO in the subfolder Elements, in the file Besselian.dat

Using data from https://eclipse.gsfc...hp?Ecl=20240408 (seems to be updated from time to time) and changing DeltaT from 74.0s to Jubier's 69.1s I get sufficiently good agreement by changing the entry to:

 

2024 Apr 8 Total (Espenak)
2024 4 8 15.0 18.0 21.0 69.1 37
0 0/0 TOTAL
-0.3182440 0.2197640 7.5862002 0.5358140 -0.0102720 89.591217
0.5117116 0.2709589 0.0148440 0.0000618 0.0000615 15.004080
0.0000326 -0.0000595 -0.0000020 -0.0000128 -0.0000127 0.000000
-0.0000084 -0.0000047 0.0000000 0.0000000 0.0000000 0.000000
0.0046683 0.0046450

(no guarantee)

Referencing back to Fred's KAS presentation, he did say, when asked, that you could just edit your current version to an updated delta T value and have the confidence of your current installed software rather than updating to a newer build.

 

I was not advocating to necessarily use the v3.9.1 build, but rather saying it does contain the last known update of delta T. I am using it because it includes support for Canon mirrorless bodies. I have no choice.

[starrycanuck]

Referencing back to Fred's KAS presentation, he did say, when asked, that you could just edit your current version to an updated delta T value and have the confidence of your current installed software rather than updating to a newer build.

 

I was not advocating to necessarily use the v3.9.1 build, but rather saying it does contain the last known update of delta T. I am using it because it includes support for Canon mirrorless bodies. I have no choice.

Given that I can always reinstall the previous version, I did download the "beta" and then added a new entry to the Besselians file using the data provided @KevinMerchant (thank you!).

 

Unfortunately, while I do see minor timing difference between the default and modified Besselian data, I'm still seeing a 20s - 30s gap between EO calculated contact times and umbral duration vs. what Xavier's map shows ... EO is later/longer in all cases.

Something else going on ... my first time with EO so could well be me but is interesting. Worse case, I can overwrite the contacts manually in EO but would like to understand the cause of the variation.

 

[zbadger]

I am the creator of this thread and appreciate the comments and suggestions. I am using version 3.7 because the laptop I used in 2017 doesn't even recognize my 7D Mark II camera anymore. So I went to a lesser powered laptop that's a little newer and sure enough it recognized my camera by using version 3.7. So I'm a little scared to update to a more current version but I do have a mirrorless camera that I'd like to try also.

 

So this next question comes from a fella in his 70s who is not that tech savvy. Is there any way I can download onto my laptop a second version of eclipse orchestrator which is the 3.9 version without affecting or deleting my 3.7 version? Then I can try the new one without affecting the 3.7 version?  Thanks.

[OJN]

Given that I can always reinstall the previous version, I did download the "beta" and then added a new entry to the Besselians file using the data provided @KevinMerchant (thank you!).

 

Unfortunately, while I do see minor timing difference between the default and modified Besselian data, I'm still seeing a 20s - 30s gap between EO calculated contact times and umbral duration vs. what Xavier's map shows ... EO is later/longer in all cases.

odd contact times.JPG

Something else going on ... my first time with EO so could well be me but is interesting. Worse case, I can overwrite the contacts manually in EO but would like to understand the cause of the variation.

This is ±1s what is calculated by http://xjubier.free....lc_Diagram.html

and consistent with the results of my besselian.dat

[starrycanuck]

I am the creator of this thread and appreciate the comments and suggestions. I am using version 3.7 because the laptop I used in 2017 doesn't even recognize my 7D Mark II camera anymore. So I went to a lesser powered laptop that's a little newer and sure enough it recognized my camera by using version 3.7. So I'm a little scared to update to a more current version but I do have a mirrorless camera that I'd like to try also.

 

So this next question comes from a fella in his 70s who is not that tech savvy. Is there any way I can download onto my laptop a second version of eclipse orchestrator which is the 3.9 version without affecting or deleting my 3.7 version? Then I can try the new one without affecting the 3.7 version?  Thanks.

I don't believe so. The guidance on the EO download site indicates that to move to a new version, you save any modified standard scripts to a separate location and download/install the new release. It does appear to overwrite data in the same location (e.g. Besselian data, standard scripts).

 

I've not tested but I would expect the same process to work in reverse ... remove the new version and reinstall the previous to rollback.

 

If you haven't already done so, you might create a new thread to confirm anyone has successfully used your particular model with EO yet before trying the upgrade.

[KevinMerchant]

Given that I can always reinstall the previous version, I did download the "beta" and then added a new entry to the Besselians file using the data provided @KevinMerchant (thank you!).

 

Unfortunately, while I do see minor timing difference between the default and modified Besselian data, I'm still seeing a 20s - 30s gap between EO calculated contact times and umbral duration vs. what Xavier's map shows ... EO is later/longer in all cases.

odd contact times.JPG

Something else going on ... my first time with EO so could well be me but is interesting. Worse case, I can overwrite the contacts manually in EO but would like to understand the cause of the variation.

Not sure at all why that large of a gap on your setup.

 

Here are the deltas I am seeing between EO & Jubier:

• C1 - 1s
• C2 - 1.7s
• MAX - 0s
• C3 - 1.6s
• C4 - 0.9s

I wish they were in agreement.

 

I do remember seeing a comparison chart that Jerry Lodriguss produced for 2017 where there were differences in event times. Here is the link - https://www.astropix.com/wp/page/16/. Scroll down to the August 7th entry. It is an interesting read and perspective.

 

Kevin

[timelapser]

This is ±1s what is calculated by http://xjubier.free....lc_Diagram.html

and consistent with the results of my besselian.dat

I agree, starrycanuck's table looks accurate.  Were you converting from fractions of a minute to degrees or seconds correctly?

[starrycanuck]

This is ±1s what is calculated by http://xjubier.free....lc_Diagram.html

and consistent with the results of my besselian.dat

Thank you for this ... it does match. So, Xavier's map and calculator don't agree ... 

[timelapser]

Jubier's map and calculator agree within half a second or so, if you enter the same coordinates.  And they agree quite well with your EO table.  You have to be careful about minutes/seconds/fractions of a degree.

Edited by timelapser, 15 March 2024 - 04:26 PM.

[OJN]

They do agree:

 

http://xjubier.free....8.0&Zoom=6&LC=1

[zbadger]

So no one knows of a way to keep 2 different versions of Eclipse Orchestrator on the same laptop.  I am scared to death with all of the problems I have had this time with EO getting to recognize my camera (compared to 2017), that if I install the newer version 3.9, that if 3.9 does not work and I try to uninstall it, I might not be able to remove all the remnants of it and not be able to get version 3.7 to work again.

[SkipW]

Can you do a full system backup before uninstalling 3.7, then restore the system if 3.9 doesn't work properly? You would probably want to do another backup before the restore if you changed anything else in the meantime.