Talk:Reeves AN/MSQ-77 Bomb Directing Central

Math

AN/MSQ-77 Modeling Errors

Bomb release velocity: The BTG simulation used A/C velocities prior to bomb release, so although the A/C flew somewhat steady, the actual release velocity differed due to perturbations (e.g., wind gust at release), velocity corrections not processed by the BTG, and for salvo releases (e.g., B-52 wing and fuselage bombs) the climb rate as the bomb load lightened. (The AN/MSQ-77 could control fighter-bombers conducting toss bombing.) Salvo releases also caused the mean bomb release position to differ from the track position used to command bomb release.
Bomb release delay: In addition to error in the release delay, errors in the modeling used in the bomb release algorithm reduced bomb release timing accuracy, e.g., modeling errors causing predicted impacts inaccurately closer to the target would delay release until after a more accurate release point.
Bomb release position: ECC at the simulated bomb impact was based on the simulation's last BRP (actual A/C position when integration ended), so shorter bomb runs placed the integration end nearer the actual BRP for lower ECC error (lateral bomb run directions relative to the radar beam also reduced ECC error).
Drift error: Crosswind acceleration on the bomb(s) was not constant despite being estimated from the constant drift angle provided by the aircrew. Drift error included the delay for the airsteam to effect ordnance released within bomb bays, as well as the delay for salvo-released bombs to separate and have individual aerodynamic loading not affected by the other bombs.
Integrator error: Different simulation rates for computing velocity and position were acceptable when the 6 integrator amplifiers were aligned within tolerances. For example, an out-of-tolerance 1% faster integration for the altitude position output over a 30 sec fall time (0.3 sec) at 600 mph (970 km/h) groundspeed would result in an earlier simulated impact about 264 ft (80 m) short. This horizontal simulation error caused by the vertical electrical error resulted in the separate AN/MSQ-77 bomb release algorithm comparing the target position & shorter simulated impact and delaying the actual bomb release point from nominal for a physical overshoot by about the same amount.
Targeting error: Target estimation error from the DASC was ~16 ft (4.9 m), and the AN/MSQ-77 site position also had error (e.g., slight coordinate system differences for the target and radar coordinates). For example, the LS-85 site estimation after the Heavy Green installation included surveying of nearby peaks' points followed by a "fly-in" conducted for LS-85 geolocation with LS-85--tracked aircraft overflying the points (surveyors on the peaks observed the flyover precision).

I tweaked the recent anonymous edits and moved the corresponding quote box and math equation section here for discussion. That content is generally accurate and sourced, but seems to me to be a bit too much detail. If it's not, it can be moved back -- particularly if similar pages have the corresponding level of detail. 30 SW (talk) 20:13, 14 July 2012 (UTC)

$\mathbf {r_{impact}} (t_{5})\approx \mathbf {r_{SBI}} (t):=\mathbf {r_{A/C}} (t)+\mathbf {\Delta } \mathbf {r} (t_{1},t_{2})$ for ${t>t_{2}},\quad$ where $\mathbf {\Delta } \mathbf {r} (t_{1},t_{2}):=\int _{t_{1}}^{t_{2}}\left(\int _{\tau _{1}}^{\tau _{2}}\mathbf {a} (\iota )d\iota \right)+\mathbf {v_{A/C}} (\tau )d\tau$

where

r = East (X) and North (Y) position from radar and height above earth (Z) for actual/simulated bomb impact and for radar-measured aircraft position (simulated BRP)

Δr = simulated displacement of the bomb caused by simulated accelerations and velocities during the trajectory

t = time during bomb run, e.g., start and end of the analog integration (t₁ & when Z_bomb=Z_target, t₂) as well as
     t₃ time to command the release, t₄ actual bomb release, and t₅ at actual impact

τ,ɩ = integrator simulation time (e.g., the 3 velocity-to-position integrators had slightly different simulation rates dτ_h, dτ_N, & dτ_E)

a = the modeled accelerations on the bomb that are integrated during the simulation to compute changes in simulated bomb velocity

v = time-varying A/C velocity used throughout the integration time, τ, to simulate the bomb release velocity

References

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Requested move 16 August 2024

Reeves AN/MSQ-77 Bomb Directing Central → AN/MSQ-77 – It is common practice when naming articles for devices which use the American military JETDS naming convention for the article to be either AN/MSQ-77 or including the system name and type like AN/MSQ-77 Bomb Directing Central. For many examples, see Category:Military electronics of the United States. This would make the page far easier to locate since most users will search for either "AN/MSQ-77" or "AN/MSQ-77 Bomb Directing Central" (the redirect already exists for that one). It is not typical across Wikipedia to place the Manufacturer into the article name, such as Reeves AN/MSQ-77. I am not able to find any examples like that. But I am open to ideas. Please share your thoughts — TadgStirkland⁴⁰¹ (Tadg^Talk) 22:29, 16 August 2024 (UTC) — Relisting. RodRabelo7 (talk) 11:32, 25 August 2024 (UTC) — Relisting. Reading Beans 12:03, 25 August 2024 (UTC)

Survey

Feel free to state your position on the renaming proposal by beginning a new line in this subsection with *'''Support''' or *'''Oppose''', then sign your comment with ~~~~. Since polling is not a substitute for discussion, please explain your reasons, taking into account Wikipedia's policy on article titles.

• Merge with Combat Skyspot. I'd suggest merging as a preferable option because it's not clear there's sufficient information specific to the AN/MSQ-77 enough to support it's own article, without repeating the majority of the content from Combat Skyspot which covers both types of system. We do not actually follow a consistent practice when it comes to naming schema for articles under the Joint Electronics Type Designation System. See, e.g. Martin AN/GSG-5 Battery Integration and Radar Display Equipment, Martin AN/FSG-1 Antiaircraft Defense System, Reeves AN/MSQ-1 Close Support Control Set, Reeves AN/MSQ-35 Bomb Scoring Central, Hughes AN/TSQ-51 Air Defense Command and Coordination System (moved by the OP less than a week ago to remove the Hughes), etc. For other naming conventions (e.g. the Tri-Service convention for aircraft names) we regularly name the manufacturer first. So I'm not sure that we're accomplishing anything by moving the manufacturer out of the name. ⇒SWATJester ^{Shoot Blues, Tell VileRat!} 02:54, 27 August 2024 (UTC)

  Hi @Swatjester… I understand what you’re saying. But, when I made the request, I had verified the vast majority of AN/ equipment articles did not use the manufacturer name as prefix to the article title. See Category:Military electronics of the United States, but ignore the many redirects listed there.

  As to merging with Combat Skyspot, I only have two reservations but I do see the possibility of a merged article, AN/MSQ-77 Combat Skyspot as an option. My reservations are:

  1. Although the articles mention each other, the primary focus of each is significantly different. One highlights technical specification while the other documents a historical event. Which one would be the primary purpose of the merged article; the system or the military operation?
  2. Merging would not particularly improve either article. Today, they are both pretty good in their own way. Merging would risk creating a Frankenstein monster effect; a very large article with a smattered organization.

  But, I’m not completely opposed to merging. Depending on the outcome of this move request, wouldn’t we need to start over with a merge request? — TadgStirkland⁴⁰¹ (Tadg^Talk) 05:29, 27 August 2024 (UTC)

I don't think that article title would be correct. "Combat Skyspot" was the name of the operation, not the equipment. However, the operation (ground directed bombing) was specifically designed around the usage of the MSQ-77 ground radar, and the current MSQ-77 article content is almost entirely about it's usage during that operation with only a few sentences devoted to post-Vietnam war history (mostly about the status of the remaining units, and mostly content that can easily be displayed as table data). If merged and redirected correctly, it should not create a Frankenarticle effect -- unsourced and unreliably sourced information (note the maintenance tag) should be removed, and duplicate information should not be merged. The result is that we would not be maintaining two, sloppy, separate sets of information across two, sloppy, separate articles. We could instead focus on cleaning up and improving a singular, broader article. Organizationally, one way this could fit cleanly is by having the MSQ-77 and TPQ-10 radars each get their own section on the Combat Skyspot page, which would incorporate the appropriate parts of content currently under the "development" and "operations" sections as well as the merged content from the individual radar pages. If necessary, we'd also add a "legacy" or "post-vietnam history" section. We have well over a dozen AN/PRC and AN/URC designations that are covered by Survival radio, so it's not like this is a particularly extreme example, either. As to starting over with a merge request, that seems unnecessary especially in light of the relatively low attention this page has gotten. Unless there's reason it would be controversial (which, if this discussion results in a consensus to merge, it's definitionally not), anyone can simply be bold and do the merge. ⇒SWATJester ^{Shoot Blues, Tell VileRat!} 08:04, 27 August 2024 (UTC)

@Swatjester, Combat Skyspot operation was indeed designed around the AN/MSQ-77 and AN/TPQ-10. But neither system was built specifically with that operation as their primary reason for existence. Skyspot was one employment of those systems. Neither were they the only Ground-directed bombing radar systems. The article notes the MSQ-77 began service "in 1958 (long before Vietnam) at Roosevelt Field... and Matagorda Island... for Busy Skyspot" and was in-use until "near the end of the Cold War." It also mentions other sites, like Nellis AFB Bombing Range and more including Korea; all of which implies it had quite a long history of use. The TPQ-10 started its life deployed to Guantanamo Bay Naval Base supporting operations around the Cuban Missile Crisis, also before Vietnam. My only point is, the operation was one use / employment of both systems. But both systems have extensive histories beyond that one operation. In fact, the TSQ-10 is barely mentioned in this article (only appears in 3 spots). I feel that the radar system articles stand alone on their own as well as the myriad of aircraft articles that are separate from the many operations they were featured in. Just my (one) opinion. Would love to hear from others. (Sorry for the lengthy reply. Good conversation.) — TadgStirkland⁴⁰¹ (Tadg^Talk) 15:10, 27 August 2024 (UTC)

The problem is that the majority of that content about the MSQ-77's usage outside of Combat Skyspot is either entirely unsourced, or sourced unreliably. What I'm suggesting is that *after* the material that shouldn't be there is removed, there is insufficient content unique to the MSQ-77 remaining to support an article outside of Combat Skyspot. For instance, the line you're referring to about Roosevelt Field and Matagorda Island should be removed as original research. The citation for the Roosevelt Field claim simply contains a quote about a real estate sale that does not mention the MSQ-77 at all, and thus does not support the claim that it was the first MSQ-77 site. The external link for the Matagorda Island claim is to a Tripod blog and should be removed, as well as the subsequent claim about retirements, which is a link to a Google Groups email. Only the last one, noting that a single MSQ-77 is currently a museum piece at Ellsworth AFB, is even valid, and that's a perfectly acceptable data point to merge in a "legacy" section. Even in the lede of the article, the statements about it being used post-war for bomb scoring are not found anywhere else in the body of the article, which is a violation of WP:LEDE. So, again, once all the inappropriate content is removed and the article is cleaned up, the only parts remaining essentially completely overlap with the Combat Skyspot article. ⇒SWATJester ^{Shoot Blues, Tell VileRat!} 17:03, 27 August 2024 (UTC)

Ya' know... Now that I've taken a closer look at this article, most of the citations are either dead links or refer to things like a technical manual (tech order) that I can't find anywhere on the web. Maybe you're right and the meat of this thing is rancid. — TadgStirkland⁴⁰¹ (Tadg^Talk) 22:50, 27 August 2024 (UTC)

@Swatjester the current article cites 25 sources. How do you come to the conclusion that, it's not clear there's sufficient information specific to the AN/MSQ-77 enough to support its own article. ~Kvng (talk) 15:04, 29 August 2024 (UTC)

How did you come to the conclusion that my concerns had anything to do with the number of sources, rather than their content? The count of number of sources has nothing to do with what time period the content of the article focuses on; and if you've followed the discussion above, you'll note that, as Tadg mentioned, a great many of those sources are either dead links, or wholly unreliable sources. Regardless, the vast majority of the sources, both the invalid ones and the valid ones, refer to the Vietnam War usage of the system during Combat Skyspot. ⇒SWATJester ^{Shoot Blues, Tell VileRat!} 15:11, 29 August 2024 (UTC)

I did not have a conclusion; I was just asking a question. It appears the question is answered in parts of the discussion I did not read. Thanks for the summary. ~Kvng (talk) 15:23, 29 August 2024 (UTC)

Discussion

Any additional comments: — TadgStirkland⁴⁰¹ (Tadg^Talk) 22:29, 16 August 2024 (UTC)

Note: WikiProject United States Government, WikiProject Telecommunications, WikiProject Military history, WikiProject Systems, WikiProject Engineering, WikiProject United States History, WikiProject Vietnam, WikiProject United States, WikiProject Technology, WikiProject Electronics, WikiProject Computing, and WikiProject Aviation have been notified of this discussion. Reading Beans 12:02, 25 August 2024 (UTC)

Relisting comment: Relisting to give more timeframe for notified WikiProjects to comment. Reading Beans 12:03, 25 August 2024 (UTC)

• Comment. Category:Radars of the United States Air Force currently includes four articles with named manufacturers; three Reeves and one Westinghouse. I'd suggest this request be widened to include them. — Cheers, Steelpillow (Talk) 14:16, 25 August 2024 (UTC)

  Hi @Steelpillow… If I remember right, I submitted a separate request for each of those as well. They each probably have their own discussion, unless I missed them. Thanks. — TadgStirkland⁴⁰¹ (Tadg^Talk) 05:03, 27 August 2024 (UTC)