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Re: Occult4 101
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 |
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Re: Couple of Quick Questions
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 |
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Re: Occult4 101
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 |
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Re: Occult4 101
George, I hear ya on wondering where the hours in the day
go.? My days are busier now in retirement, than when I worked 40+ hr
weeks. In using a DOS command line file search, I confirmed that the chevron zipped folders from
"Maintenance -> General Downloads -> were copied into the
C:\Occult4\Download folder, but not unzipped, nor their interior files copied elsewhere.? Henceforth, I removed Occult, it's files, folders
along with a few computer reboots, started afresh from scratch.? With the basic code installed, my site, email, etc details entered - I'm back at the "Maintenance -> General Downloads" -> and selected the "First 10 Download All" button. After several files download fine? - the? Convert Astrob and MPCorb files box was displayed. AstOrb was already preselected and I'm looking at the guessing at what is the best value for the "Specify 'mandatory' minor planets" entry? Do I need to "Add" them or select the "Convert" and do I need to run this download several times again and then select MPCORB, then AstDyS-2 and then Gaia sequentially? (ref screenshot) None of the Help options worked for me.? Even after going through Dave's suggestions under " if Help is not working"... Once
I move onto # 11 and beyond, including #s 21-23, I'll load them in the order George mentioned.?? I
had most likely originally installed those crucial asteroid database files in numerical order, which may have
triggered the initial Occult user issues. ?? I emailed Dave H, kindly asking about the "Convert Astrob and MPCorb files' pop-up box and how best to proceed? with the? "Specify 'mandatory'
minor planets" entry value, Add or Convert and having to run this download several times again with MPCORB, then AstDyS-2 and then Gaia sequentially.???? With shin pads and hockey pads on - I await his reply. ? Will let you know... - Roxanne |
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Re: List of Observers
For some reason my previous?bio was not visible...? Observer:? Rick Bria What's (approx) the faintest magnitude you can normally video record?:??~13 What
best describes your occultation ability:? Experienced Willing/Able
to "Go Mobile"?:? Yes, if I get a Astrid |
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Couple of Quick Questions
In reading the email about making Titania observations on 21 November, it sounds like the most important aspect is high time resolution.? I didn't see anything in the request about using filters for atmospheric measurements (since it sounds like the atmosphere is so thin to be undetectable with our techniques).? The reason I'm checking is I still have my two band dichroic system from the last Pluto occultation sitting on the shelf waiting for a chance to be used.? Tom and Frank--this observation would be very worthwhile doing from Martz and Kopernik Observatories if you are available.
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A couple of you said you were also waiting for your Astrid as I am.? Are you all in the first batch?? Mine is now scheduled to arrive on Tuesday.? Mark has provided excellent instructions for assembly and use, but it would be great if we could also trade notes on getting them running.
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Steve C
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Re: Occult4 101
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 |
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Re: Occult4 101
It was only a couple of weeks ago that I suddenly (without any understanding of why) could run Occult cleanly.? Prior to that, it would crash at some random point in the first 100 asteroids saying there was a formatting issue with the star catalog (same with Gaia 12, 14, and 16).? But I'm with Kevin H on this now that it "works", when I run it, I don't get too many matches with what can be found on OW.? So I'd also be interested in a Zoom session on this topic at some point.? BTW, we have a Zoom subscription that I'd be happy to use for any discussions among this group to get around the limits of the free version.
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Steve C
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Re: Occult4 101
Hi George. If you do a "solo" video and put it in your dropbox, I'd watch it too. I'm forever frustrated that when I run Occult4 for my site, the results don't match those I get on OW hardly at all. I must have some filter or database wrong, but it's pretty frustrating. If you flag me that there will be an event of a certain asteroid, I can limit the search to just that asteroid and sometimes have it show up, but not otherwise. I think there must be something wrong in my setup.? ...Kevin On Thu, Nov 2, 2023 at 5:19?PM George Viscome via <georvisc=[email protected]> wrote: Roxanne: |
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Re: Occult4 101
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 |
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Re: (1200) Imperatrix Nov 2 ~8hr UT
Folks:
1st, Congrats to Steve and Kevin on the Palisana hits! Please pardon the length of this post, but I'm thinking some might enjoy a "story from the trenches"... So... I was able to try for the (1200) event this morning at the unGodly hour of 4:17am (8:17UT). Had some high thin clouds but managed to get a usable video. A couple inches of snow on the ground here and an outside temp of 18dF (tho 60dF in the observatory's warm room). Didn't bother turning on the cooler for the QHY (the camera read a sensor temp of -11.2C = approx 12dF). Probability of the (1200) event said 93% (JPL-based prediction)... but... I had noticed that the shape model was quite elongated in the direction of the path, and I was somewhat close to the path edge. So it might be that my probability could be a bit lower. Well..... ?????? I recorded a Miss. Considering the 'effort' in setting up and dealing with the cold I decided to look at my nightly Occult4 listing of events (for Nov 2) and see if there was anything promising coming up soon before I closed things down. Occult4 listed an event (192851) at 5:01am (9:01UT) involving a 12.2 mag star. Probability said 13% chance. I decided to try for it. In short........ Another Miss. Went back in the house and scanned the list again before closing up......... Noticed an event (9977) at 5:36am (9:36UT) which was high up in Gemini. Decided to try for it - despite the Probability of this one being only 7% (I was on the 1-sigma line). I didn't notice until I was printing the chart that the combined mag was 15.0, the Target Star was VERY close to another star, and it was only 8 degrees away from the 77% illuminated Moon(!!!).???? Decided to try anyway. Nice thing about this one was the asteroid was very near its stationary point, thus it had a max duration of 9.2 seconds (and as a result, a JPL stated time uncertainty of +/-29 seconds). This helped - as I could run the QHY at a longer exposure. (BTW this was the coldest outside temp I have ever run my QHY). It turned out that an exposure of 0.65 seconds gave me a fairly strong SNR, but it was VERY near a brighter star. (Later I examined the image and was able to make out stars to a bit fainter than mag 16.0 ! - see attached). Anyway......... Damned if I didn't hit it !!! (see attached image). A clear, very obvious, 8 data point positive, with a duration of 5.0 seconds (SNR=5.47). It was a bit of a challenge to get PyMovie to "see" just the Target Star (and none of the closer brighter star), but an 11x11 Static aperture offset to one side did the trick. I will be forwarding this video to Bob Anderson (and Tony George) to see what Bob might come up with as a better way to isolate a Target Star that is very close to another. (If anyone would like a link to this video, just ask. I'll forward the link when I have posted the video). ????? Woke at 3am... Back to bed at 6:30am. Gotta love it. This is actually a common way I've hit Pos events. 20 minutes prior to this Pos I had no idea I would be trying for this event. Don't feel left out tho...... for all 3 events I went after, the paths all crossed over just northern NY - and none seemed to cross over anyone I know of on this list. Happy Shadows, George |
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Re: (1200) Imperatrix Nov 2 ~8hr UT
Kevin (G):
Yes, I have your site data (the lat/long of the WAS Observatory), and I've had you in my Occult4 "site list" for some time now. But.... Please consider going to the NEUS post "List of Observers" and entering in your data - so others will know your info. George |
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Equipment Available
All,
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Just in case someone wants them, I do have 2 Kiwis, 2 Watec 902s and 2 Stellacam EXs I never use any more.? If you know anyone who'd want them (and really use them), happy to give them away.? Since they haven't been turned on in a couple of years now, I'd test them prior to sending them to someone to make sure they still work.
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Steve C
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Re: Palisana This Evening
Kevin,
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FYI, PyOTE measured my magnitude drop as 0.13.? Event mid-point time was within a second of the predict.??
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Steve C
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George Viscome
rickbria22
Steve C
Kevin Hartnett
