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Steve:

Certainly take care of yourself 1st. There will be other events... Best,

G

Folks:

If (by some miracle) it's clear on Nov 15th, here's an event that at least one of the 3 listed observers is sure to hit -- if not a hit by all 3 (and 3 perfectly positioned chords). Observer locations indicated by the small orange dots (and my location by the orange circle). See attached.

Clear Skies,

George

Roxanne:

You wrote:

All:

Some further notes....

Kevin is correct, "It all depends on what you want to do" - ie., how deep you want to search ---- what you want to set your mag limit to, what's the smallest mag drop you feel you can discern, what's the smallest asteroid size to use in a search.... etc.

Some have mentioned that they get an error after their 1st 100 or 300 asteroids. I find this puzzling. Essentially, with Occult4, it should either be finding events or not (working or not working). I can only think of 2 things that might cause this...
1) There's was an initial error in formatting in one of the 3 downloaded asteroid databases. I've seen this happen a few times. Solution - reload the 3 databases. You may need to wait until the next update to a database for the issue to clear.
2) You are overloading the output in your Search.

First, there is a default limit in Occult for the number of events it can find in a single Search. The default is 20,000. This number can be found by going to the Main Menu --> Maintenance, then go down to "#11". I have mine set at 40,000. But as stated in the program, "If the number is too large, the program may run out of memory". 40,000 seems fine for both my Win10 computer (4Gb memory), and Win11 computer (32Gb memory).

You can overload the output in a couple ways.......
a) You are searching too deep. You may need to relax your mag limit, mag drop, and asteroid diameter.....

FYI: The number of events you see listed in the output (in List & Display) is most likely [much] smaller than the number of events the program actually [initially] finds. When you press "Search" the program builds up a list of events it finds ("behind the scenes"), then at the end of the Search it takes into account the "Filter settings" in "List & Display" and displays only the events that pass those filter parameters. There is a way, during the initial Search, to limit the number of events that Occult4 finds "behind the scenes" -- which helps to avoid an "overload" of events. This can be done via a setting on the "Search Page", and is in the aqua-colored box below the star catalog. This involves setting a number in the "Passes within" box (see the image I attached in a previous post). There I have mine set for "Passes within 900 km" (of the Lat & Long of my observing site). If this box is unchecked, Occult4 may actually build a database (behind the scenes) for all events it finds that fall somewhere OVER THE ENTIRE EARTH! I think you can see this has the possibility of creating a VERY large "behind the scenes" list of events - and can result in an overload error. So I would suggest that users check this box, put a value in it (maybe 500km), and make sure your approx Lat & Long are correctly displayed.
Also in this aqua-colored box, set a realistic mag drop, and star catalog mag limit. This will also prevent any overloads. [I've found mag drops of less than ~0.15 mag give me more headaches than it's worth - wondering if the "drop" I see is real or just noise].
Make sure all 3 boxes are checked.

Another way to have a Search hault due to an overload......
b) You are doing a search for too long a period of time.
I have seen overloads happen (rather easily) this way. I know folks might like to search for a month or so at a time. I feel this is NOT WISE unless your search parameters stop at something like mag 11, you are using GAIA 14, and any asteroid is larger than perhaps 20km.

After much trial and error, I would really -suggest- you do the following:
Do your (normal) searches for one day (well, actually, night) at a time (!!!!)
I find doing searches for just 1 'day' convenient. I just keep track of the weather forecast a few days ahead, and if I see the potential for a clear night coming up, I go over to the computer, enter in a Start and End date of the same day (number). I then start the search and walk away from the computer and come back later - when I see a list of events displayed. If it's clear out, it's then very handy to just consult that nightly file. After that night has passed, simply delete the file.
....Or you can do a nightly search just prior to an evening's observing.

"My paths don't match what I see on OW"...........
Again...,? remember the initial output from Occult4 will be based on the MPC's MPCorb database(!), and will NOT be based on JPL/Horizons. There is a further step you must do to get JPL-based predictions. Maybe I'll write that step up later, but it's better to cover in a Zoom session.

That said... There IS a way to get a JPL/Horizons prediction (path) directly --- [usually] FOR A SINGLE ASTEROID.
Do the following:
* At the Search Page, in the beige box, you will see a box saying "Select asteroid or Set a comet".
* Click on the box
* At the prompt, enter the asteroid number without parenthesis (or enter a provisional designation)
* Click OK
* Press Search
IF OW(C) predicts an event involving this [single] asteroid (for the selected night), the event should show in List & Display, and if you click on the row of text the path map that is drawn should [very closely] match that shown on OW(C) --- providing the path on OW(C) is based on JPL/Horizons.
So this is a way you can "test" the accuracy of paths output from Occult4.

FYI: When I get a JPL-based path via Occult4, it almost always matches the path in OW(C) - VERY closely (prividing the path in OW(C) is also JPL-based.

When you get an output (list of events) in the "List & Display" window, be advised that you can refine the events which are displayed by modifying the "Selection filters" at the top. We can cover that in another post or better yet, in a Zoom session.

Lastly..... If you run into an error stating that Occult4 can't "resolve" the JPL site... check your Internet connection.

Clear Skies (very wishful thinking for me lately),

George

Steve:

As far as the ASTRID... I'm on a waiting list for the 2nd batch. Mark said he doesn't know if it will be a kit (like the 1st batch), or will be "pre-build by IOTA".
I gather you get your ASTRID (kit) in the mail today (Tues Nov 7th). Keep us posted on your experience assembling and using it.
I'm sure you've seen that Mark made a video (it's on YouTube) that shows the assembly of the kit.

George

When you process a new MPCorb or other file, the data get written to the file at "\Resource Files\AsteroidElements.csv" which is what is read in by Occult-4. The last one you process is the one that is in the csv file, so that is why the order matters. If you generate a "UserAsteroid.csv" file in the "List and Display" window, it is also written in the same directory.?

When I run through a list, I run it on all asteroids, regardless of size and number of oppositions, but that doesn't mean it is the most efficient or that I recommend doing that. It depends upon what you want to do.

Roxanne (and all):

Yeah, semi-retired - in theory. Spent all weekend pretending I'm an arborist and clearing a building lot... Gotta pay for that ASTRID.....

Ok, good that it seems you have Occult accepting file downloads (and probably a good idea that you did a fresh install - tho that's sometimes a drag to do).

Yes, when you are updating some files under Maintenance-> General Downloads, after that file is downloaded it will say something like, "You will now be taken to update your asteroid database". You will then see the "Convert" stage....
What I do at that point is to exit out of the "Convert" that is showing.
Reason being... I want to load the asteroid files in the specific order of Astorb, then AstDyS-2, and lastly MPCOrb.
What you will do next is just what the program wants, but you'll do it in the order that works best.....
So now go to download #23 Astorb....
When you select Astorb, it should download. Upon completion of the download, you are taken to the (same) Convert window. What "Convert" does is reads the Astorb file and converts it into a format that Occult can use.
At "Convert" several things show.... (as in your image)....
* Include MPs larger that "X" km. Here I use 3km. But as you know the smaller you go, the numbers increase 'exponentially'. You could try 3, but maybe to start you might try 5 or 6 (you can change this later). [You can revise the diameter setting the next time you update the 3 database files].
* Numbered MPs only (I leave this unchecked).
* Limit to 3+ oppositions (I like this checked). If unchecked the additional asteroids that will be included will have very large uncertainties (ie., huge 1-sigma bounds). Good Luck getting an occultation on those!
*"Mandatory MPs.." This means, no matter what, I want the numbered MP(s) to be included in my database - irregardless of any above specified setting. For example you might want to include some of the Near Earth Asteroids that IOTA likes to go after --- like Phaethon, which are under 3km. You don't have to enter any additional numbers here, but if you don't add some small, important ones, they will NEVER show up in your Occult search (as they simply won't be in your database).
--- After you configure what you want, then you press the "Convert" button. Convert builds a subset of Astorb in a file format that Occult can use.
It should then show you a folder where Astorb is stored. Accept this by clicking "Open". ("Open" overwrites any older file).
You will see a "Convert" progress bar and it should eventually say "Astorb conversion complete".
Next, you do the exact same steps for AstDyS-2 (Convert should remember your selection settings), it will show you the folder where AstDyS-2 is stored, you press "Open", and it should say ASTDyS-2 conversion complete.
Lastly do the same thing for MPCOrb.

The reason you load these 3 files is that none of the asteroid database files contains all the info that Occult needs to make a prediction. For example, MPCOrb does not contain any info on the uncertainty of the orbit - so the 1-sigma uncertainty lines could never be generated from MPCOrb. Nor does it contain info on the asteroid's assumed diameter. So in short, Occult has to draw from all 3 databases to get all the info it needs to properly make a prediction.
Now, why you do MPCOrb last.........
I may be wrong on this - as it's been years since I tried otherwise - but I believe that the last database file you load is the one that Occult uses for the actual orbital elements (All 3 files? contain orbital elements, tho they may be slightly different!). For example, if you load MPCOrb last, your initial "Search" will be based on the orbital elements in MPC's MPCOrb.
You can see the orbital element database that Occult uses - as it's just to the right of the "Search" button when you start a search.
See the attached image for how I configure my Search Page.

I hope the above helps.

The weather is due to turn very poor for me soon (freezing rain)... so chainsaw work will be put off. Maybe we can do a Zoom session (quite?) soon.....
[November is usually VERY, VERY cloudy for me... Doubt I'll have any stars winking at me for a while].
Let me know if this helps and if anyone else has questions / problems / thoughts / corrections / intense criticisms..., etc.....

Later??? -G

On Wed, Nov 1, 2023 at 09:34 PM, George Viscome wrote:
My info:

Observer: Kevin Green and/or students
Nearest Town: Westport, CT
What's (approx) the faintest magnitude you can normally video record?:M15?
What best describes your occultation ability [Experienced / Novice / Occasional / Student / Beginner / Other] : Experienced
Observe from Home/Observatory? (list scope aperture): Observatory
Willing/Able to "Go Mobile"?: Can yes.
Aperture of Mobile Scope(s): 9.25 inches
Camera(s) used for occultations:? ?QHY174M-GPS for Observatory
Are your timings obtained from GPS? (if not, describe): Yes
Can You Measure/Reduce Your Own Events?: Yes
Member of IOTA?: Membership has lapsed. Need to fix this.
Other Info: Actively recruiting students for some observations. Also actively working on automated station(s).

As George mentioned, my experience is that the primary reason for the difference between Occult 4 output and Occult-watcher is the fit used. The JPL fits include Gaia DR3 data on 150K+ asteroids and the MPC fit does not. I still make a first past using the MPC data and then refine with the JPL fit on a subset of the events. The reason is that the JPL fit calls Horizons which takes a longer time, and it is faster to run using the MPC data. The JPL data so far does not include the most recent Gaia data which extends to 2020, so for the moment, the Gaia data are from 2014-2016.

If Occult-4 is crashing, maybe I can help here. We got it to work, so y'all should be able to. Can you post a screenshot with the exact error message? It may be in the orbital parameters file. Knowing which rock it crashes on would be helpful. Before doing that, update to the latest MPCorb file and latest Occult-4 version.

The reason for uploading Astorb and Ast-DyS-2 first is that they include fit error data in their file and MPC does not, so the errors are first calculated using the other data-sets. Of the 3, MPC seems to have the largest data-set.

I still get some fits out of Occult-4 that change dramatically when uploaded to OW and they do a fit, and I haven't tracked that down as yet, but it is only a couple of percent of events that do that now, so I just live with it. Most of the events generated agree with what gets posted on OW.

Hi All:

Pardon the delay. Like most on this thread, I'm also semi-retired (trying anyway) - but the phone keeps ringing.... (taking down trees today - clearing a building lot).

It looks like the issue is deeper than just how to use Occult to get results, it's, for some, --- how to get it running at all.

Ok, some "basics"... I'll mention some "very general" items... My experiences...

I initially installed Occult4 (many years ago) on a Win10 computer. My working version is on a new (very high performance) Win 11 computer. So I have it installed on two computers.

NOTE: Occult4 really demands a computer with some "umph".... I wouldn't suggest running it on anything earlier than Win 10.

Win 10........
The Win 10 computer I think is now close to 10 years old(?). It only has 4Gb of memory. Prior to today I last updated Occult4 on it back in August. (I just updated it to have a "backup" version). Today I updated both the program and all data files and it runs Occult4 without a hitch. (....But compared to the Win11 machine, it runs at 1/5th the speed - slowly).
I looked and I see Occult4 is installed under C:\Program Files (x86) - on this Win10 machine -- ie., C:\Program Files (x86)\Occult.
When I start Occult4 I always get the message: "Do you want to allow this app from an unknown publisher to make changes to your device?" ...And it lists the file Occult.exe. I say yes. [Occult4 isn't a generally recognized program such that it has "security certificates" issued/verified].

NOTE: When first installed/running, from the Main Page, you must first go to Maintenance, and then to "User Settings" and configure the program for it to initially run. This includes your Site Name, Lat, Long, Elevation, Time zone.... Most of what's listed will already be configured for you, so you don't have to mess with much. Most of what you do here will only need to be done once.

Once started, and at the Main Page, when I first tried to update the program (today), it wouldn't install the .zip (update) file... In my virus scanner it logs the message: "Harmful website http://www.lunar-occultations.com/occult4/occultupdate.zip blocked". Then I remembered that on my Win10 computer I must first temporarily shut down my virus scanner (supplied by my Internet carrier - Spectrum). When I do that, the update proceeds fine. After the update is done (takes about a minute), I then turn the virus scanner back on.???? ?
Odd, but an understandable security issue for a program the isn't "generally recognized" - plus the fact that I have it installed in a /Program Files (x86) folder.
So FYI.... After I have the update installed and the virus scanner is back on, I can go to the "Maintenance" tap of the Main Page, then "General Downloads". The files that need to be updated are then indicated (by chevrons >> if I recall).
To answer Roxanne's question........ "Where do I unzip these files to?"...
When it's indicated that a file needs to be updated, I just simply click on the file, a download begins, and it unzips itself and automatically updates the file in the folder the program deems correct. I have never had to direct the update to a specific folder... the program knows where to place the new, updated file. [My virus scanner is on at this time and doesn't interfere with the support file updates].
The crucial asteroid database files that need to be updated (all files are 'crucial' but those concerned with generating the predictions) are:
#23 - Astorb
#22 - Ast DyS-2
#21 - MPCorb
(I UPDATE THEM IN THIS ORDER - I forget why, but there is a reason).
FYI: For GAIA Star files I only have the following loaded:
#40 - Gaia 16
#41 - Gaia 14
(I only use Gaia 16 tho).

I could go into a LOT more on program setup, but my typing fingers will wear out.

As for Occult4 on my Win11 machine........
If I recall correctly, a year ago when I got the new Win 11 machine, I tried to install Occult4 and had issues. As a last resort I decided to just copy the entire "Occult" folder that is under Program Files (x86) on my Win 10 computer, and I wrote that verbatim to my Win11 computer --- BUT --- I see I installed the "Occult" folder directly under the C:\ drive ---- (C:\Occult).
In short, this works fine.... I get no notice of ""Do you want to allow this app..." etc. I also do not have to turn off my virus scanner (same one) to do any program or data file updates. And Occult4 runs without any issues.

On occasion I have gone to do a nightly search and I have gotten an error message (both Win10 & Win11). In most cases the problem has been a formatting issue with the MPCorb file or a fomatting issue with a download from JPL/Horizons. At times I've verified this with an email to Dave Herald.

There has been mention of "the predictions (paths) I see don't match the predictions I see on OW".....
There could be one big reason for this.............
JPL/Horizons doesn't supply a file of the orbital elements of """all""" asteroids --- but the MPC does (MPCorb). Thus, your ""initial"" Search for occultations will be based on MPCorb (and not on elements from Horizons). There are often (almost always) differences in the paths listed between the MPC & JPL. The most accurate paths are (currently) paths based on JPL/Horizons. OW paths/predictions are ['almost always'] based on JPL/Horizons --- BUT --- the initial output from Occult4 IS based on MPC elements.
There is a further step you must do after you get a listing under "List & Display" in Occult4 to then get the "more accurate" predictions/paths via JPL/Horizons.
Finger muscles don't permit me to get into that now.... Suffice it to say, it's pretty easy but let's cover that later.

Let's stop here. Maybe the above will lend some insight into any issues.

Great to hear that Steve has access to a "No 40 minute limit" Zoom account. Write back and let me know if this helps and we can move further soon with a Zoom chat and cover --- whatever you want about Occult4.

'Nuff fer now..........

-G

Roxanne:

Sure... I don't proclaim to be any expert on Occult4, but I think I've managed to set it up so it gives me a very useful list of prospective targets to go after each night (I often have 20 or so ''''decent'''' events to try for per night). And it can also be set up to 'instantly' show the Probability for other sites that you add -- among other things.

Attached is a sample output involving a recent event that passed near me, but I it also alerted me that it passed very near Kevin Hartnett in MD (and I advised him of it). You can see that it shows the Probability and Event Time for my site (Rand Obs II), and at the same time computed Probabilities and Times for Kevin Hartnett (and also Kevin Green at the Westport Ast Society / M-Michaud in Canada / Sue & Alan French in Albany, NY / L. Garrett in Fairfax, VT / and the Adirondack Public Observatory in Tupper Lake, NY near me [folks I've been trying with no luck to help with occultations]). You might note that there are duplicates in the list - as the list gives me predictions based on both MPC & JPL elements.
My typical output gives me over 100 events per night -- but I go rather deep in my search.
For mobile work, Occult4 can directly link to Google Earth and you can see what local sites the predicted centerline falls closest to.

I have done Zoom sessions on Occult4 in the past and most times they have required a couple "40-minute free-Zoom" sessions (40 minutes seems to go by fast!). I'm wondering if I can screen record a [solo] walk-thru of Occult4 (configuring and use) and simply post the video on my DropBox. Then do a follow-up Zoom session for questions / clarification. Let me look into the best way to do this.

...And it would certainly help if you (or anyone) already had Occult4 installed and preferably running to some degree - ideally such that you could already get some predictions out of it. ....But we could also start from scratch too (tho it's been years since I did an install from scratch!).

I'll write again after thinking about the best way to do this.

Happy Shadows / Later,

George