WIP/Teaser: LSOBot …. BMS Carrier OP Landing Evaluation Tool
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Jeeeez I feel a little sorry to see that tremendous amount of work
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Jeeeez I feel a little sorry to see that tremendous amount of work
Sorry - not sure I understand.
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That’s the first time I’ve ever heard or read that the projection angle of the iFLOS is changed on each pass. Do you have a source document I could review? For instance:
http://www.airspacemag.com/how-things-work/the-meatball-8421491/
…my source is some short time spent on an actual CV LSO plat, watching them do it. In RL it really is all about gross weight (which also determines how the wires are set) and aircraft attitude - the lens is set based on hook to eye distance, and that can change with aircraft attitude because of trim change due to fuel burn. So the actual geometry changes…each pass, each platform - they don’t land all F/A-18s in sequence, then all C-2s, then all…etc. - they all come aboard based on fuel remaining, which means the lens is constantly being reset. Every pass.
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…my source is some short time spent on an actual CV LSO plat, watching them do it. In RL it really is all about gross weight (which also determines how the wires are set) and aircraft attitude - the lens is set based on hook to eye distance, and that can change with aircraft attitude because of trim change due to fuel burn. So the actual geometry changes…each pass, each platform - they don’t land all F/A-18s in sequence, then all C-2s, then all…etc. - they all come aboard based on fuel remaining, which means the lens is constantly being reset. Every pass.
Ok, I’m willing to accept that and I understand the visual reference will need to change as the relative pilot viewing location changes (i.e. higher or lower for one AC vs another). I think this is what you’re referring to as ‘hook to eye distance’. But that conversation is a little bit of a tangent from the root of my question.
Every document, article or description I have ever read on carrier landing systems describes the FLOS/IFLOS meatball (or meatball v datum) as a glideslope reference …. that is a centered meatball represents a glideslope of x, where is ‘x’ is determined to be the optimal glideslope for current conditions.
Earlier you seemed to be saying that wasn’t necessarily correct and that the optimum glideslope changed with each pass. So, does the IFLOS encode glideslope visualization for the pilot and does the ideal glideslope change for each pass (during a single recovery event)?
For example:
…. The FLOLS, therefore, encodes deviations of the aircraft from glideslope as deviations of the meatball from the horizontal of the datum lines. The geometry of this relationship is diagrammed in Figure 2.
For purposes of the present discussion, the standard 3.5* glideslope is assumed;
The Retinal Image of the Fresnel Lens Optical Landing System
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Yes - and that glideslope is set based on the geometry of the particular aircraft to fly the hook point into the 3 wire. Every aircraft has a nominal hook to eye (design eye) distance - the literal measurement between the hook point and the pilot design eye point. The lens is set based on this distance - RL LSOs told me that - but the geometry can also vary dependent on aircraft trim (so four wires)…aft CG and the hook may hang lower than “nominal”…which means the pilot may need to trim nose down and fly faster to put the shoe in the proper groove - I’m speculating. CV glideslope is also 3 degrees nominal, I seem to recall…at least for the platforms I’m familiar with…but this may also vary dependent on how far aft of the CG the hook point is located. There’s a lot more that goes into it as far as setting the wire, bring-back, max trap, and max decent at trap for each type aircraft goes, but that’s the main of it.
Anyway, the cadence for getting to the groove is to call: call sign, fuel state, hook down, three green, and GWT/bringback…in some priority order which I forget. Then once the pilot has the ball in sight the call is callsign, “type-ball” so as to enable a final lens set check/verify, and fuel state…while the LSO watch are yelling “clear deck” or “foul deck” so the primary can wave or land the guy in the groove - during my trip there were generally a half dozen LSOs on the plat during ops…there is never just one guy there. I only spent a week watching, and it was a while ago…I mostly just tried to stay out of their way, but it was way cool not only to watch but just to have the privilege of being there to watch. Particularly at night. Those guys are SERIOUSLY trained up.
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I believe the glide slope is above 4 degrees, 4.1 if i’m not mistaken for the Hornet anyway. If anyone knows that would be great as the glide slope seems way to shallow in BMS.
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Jeeeez I feel a little sorry to see that tremendous amount of work
I think it will work well in concert.
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Fantastic news!!! Thx :drink:
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Nice work dude! You’re a stud.
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LSOBot is released!
Great news this, Tyrant, and thanks a lot for sharing your work most of all.
With best regards,
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Just found out about this grading tool. I have tacview and I use it for DCS. only problem is it works less than half the time. Not sure whats wrong. i do have some fairly large files but the website just hangs and never loads it up.
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It’s not really designed to work with large files. Just flip ACMI off and on again before landing and you’ll get a new, smaller file that should work fine.
Also, are you saying you’re using LSOBot to grade DCS landings? I’d be surprised if that works at all.
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It’s not really designed to work with large files. Just flip ACMI off and on again before landing and you’ll get a new, smaller file that should work fine.
Also, are you saying you’re using LSOBot to grade DCS landings? I’d be surprised if that works at all.
I tried it with DCS and it wouldn’t work for me lol
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Ive got it to work a few times with DCS. tacview convert the same data right? just LsoBot just hangs for hours but it was working before
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Ive got it to work a few times with DCS. tacview convert the same data right? just LsoBot just hangs for hours but it was working before
The grading algorithm is pretty specific to the carrier in BMS. If it works with DCS then it’s a total accident, and I wouldn’t put much stock in the scores it gives. Yes the file formats are the same, but I had to bake in information that’s specific to BMS - not everything can be read from the TacView file. Those assumptions won’t hold for DCS.
If you are having trouble with it hanging, the most likely explanation is that your recordings are too long. LSOBot has to scan the entire file looking for landings. Your ACMI should not include anything more than the two or three minutes near where you attempt to trap. If you point it at a two hour mission, yeah, it’s going to just churn basically forever.
Easiest way to get a small ACMI file is to turn ACMI off (if already on} and then on again right before trapping. This will result in a new, smaller .vhs file, which you can convert into a smaller .ACMI.txt file with TacView, which will then load much faster in LSOBot.
If it’s hanging for small files let me know and I’ll try to track down the problem.