OBOE! - Mission / Script inside

[Draken35]

OBOE

Blind Bombing System

Script for DCS 2.7

by Draken35

 

Recommended reading and watching

https://www.youtube.com/watch?v=hURdl91MCNQ

http://www.rquirk.com/cdnradar/cor/chapter13.pdf

 

Principles of operations & script usage

 

The above links describe very well the principles of operation of OBOE, but in short, OBOE is a radar transponder based system used to measure distances from the plane to two ground stations: CAT and MOUSE.

 

Cat station is use to project a bean that pass over the target that the pilot must follow. Signaling is done with different sounds for when the plane is on track and short or long of it. Mouse station is used to control bomb release and signaling is Morse code. All the distances and important points are calculated in the ground prior to mission start and assuming the planes will fly in at a specific altitude and speed. These calculations will not be adjusted or corrected while in-flight, so it is very important to follow the flight profile.

 

In order to receive signals from the stations, the plane has to have line of sight with the stations. The altitude to maintain LOS is considered in the flight profile and LOS is modeled in this script. So, if you don’t hear anything from Cat or Mouse, flight higher!

 

The script will pick a target (from an available list) and provide a briefing for the mission.

The briefing consist of the target location and the flight profile used for the OBOE calculations and bomb release. The briefing also provides an attack direction (North -clockwise or South-counter clockwise in The Channel Map). In order to strike the target accurately, this flight profile and attack direction must be followed.

 

The first task is to intercept the track provided by the Cat station (steady tone on track, short pulses while short of track and long pulses for long of track) and turn into it from the attack direction provided in the briefing. You will heard a Morse X at 20 miles from the track, then a Morse Y at 10 miles and a Z at 5 miles from the track.

 

Follow the track and, at 10 minutes from the target, a Morse code warning will be heard: AAAA. At 8 minutes it will be BBBB. At 6 minutes, CCCC. Then, at 3 minutes away another signal will be give: DDDD. The signal for bomb release point is 5T, which is 5 dots followed by a dash. Bombs shroud be release at the end of the dash. The "OBOE: Sound 'tutorial'" in COMMS menu will provide examples of these signals.

 

Release heading. At the time of this writing, it is not clear to the author when the pilot should turn into the release heading but as a best guess, since it is calculated from the release point to the target, is that the pilot should start turning into the release heading when the release signal starts.

 

 

 

Morse Signals

A = .-

B = -...

C = -.-.
D = -..

5T = …..-

X = -..-

Y = -.--

Z = –..

 

 

 

 

Use COMMS Menu (other) to access the OBOE Functions:

“OBOE: Mission Briefing”:

Shows target and flight profile information

 

"OBOE: toggle on/off":

Toggles the OBOE equipment On and Off.

 

"OBOE: reset approach" :

The script keeps track of the 10min, 3 min and release signals and they are give only once This option allows for them to be reseted and the track flown again.

 

"OBOE: Report results"

Reports distance and position, using a clock face of the bombs impact in relation to the target. 6 o’clock is short, 12 is long, 3 is right and 9 is left.

 

"OBOE: Settings"

Allows to change the units in which the briefing and results are given and the accuracy of the system. The more accurate, the narrower the Cat beam is and the closer you need to get to the warning points in order to receive the corresponding signals.

 

"OBOE: Sound 'tutorial'" (Cat & Mouse)

Gives you the option to listen to all the sounds used by the script.

 

 

Mission editor:

In case you want to open the missions in the ME, the scripts and sounds are included in the respective folders. Just make sure to copy them to the places you normally use for those types of files.

 

 

Please use this thread for feedback and comments about this script.

 

    Version history
    1.00        09/22/2021    Initial release.
    1.01        09/26/2021    - Fixed 10 mins warning.
                            - changed warnings to target instead of  release.
                            - oboe.SelectTarget() returns number of selected target
                            - added bomb impact tracking
    1.02        09/28/2021  - added new sounds
                            - Modified distance to target signals 
                                - 4xA = 10 minutes
                                - 4xB = 8 minutes
                                - 4xC = 6 minutes
                                - 4xD = 3 Minutes
                            - Added distance to Cat track    
                                - X = 20 miles
                                - Y = 10 Miles
                                - Z = 5 miles
                            - changed default accuracy to 8 meters (~ times 2 = wingspan of the Mosquito)
                            - improved sound tutorial
                            - improved accuracy and reliability of the signals
                            - added optional parameter to SelectTarget to select specific target 
                             (if nill or greater than the number of targets in the list, then the target will be randomly selected)
                            - added subtitles to the Morse sounds. Default is off
    1.03        09/30/301    - replaced variable position polling frequency by a fixed one 
                            - reworked sound system
                            - added default values for release altitude, ground speed and briefing in the target list.
                              This means, that you only need to supply that target zone name. The script will generate the rest
                            - Added track intercept mark
    1.04        10/01/2021    - Restricted Mouse signals to the vicinity of the Cat track        

    1.05        10/05/2021    - Requires d35lib v1.01
                            - Added historically accurate 7.5 seconds release signal (new sound, file name 5t7.wav - triggers need to be updated)
                              Thanks Retnek!!!
                            - Added headings to the interception and warning points (perpendicular to CAT track) as reference to the briefing                 

1.06        10/08/2021    - Changed calculation of Cat track to make the release vector tangential to the track        
                            - Improve horizon LOS calculations
                            - Added path guidance information for training (overrides sub titles). Can be disabled in the script
                                XXX < YYYYm> ZZZ  SIGNAL
                                where XXX is the tangential heading to the path at current position
                                      YYYY is the distance in meters to the center of the path, max display is +/-999m 
                                      ZZZ delta between current heading and tangential . 0 = on path
                                      SIGNAL = mouse or cat signal:
                                        miles 20 | 10 | 5 : Signal from CAT distance to path
                                        10|8|6|3 mins : Signal from MOUSE, minutes to target
                                        Release : well...Guess...(remember, pickle at the end of the SOUND signal)
                            

 

 

Download here:

https://www.digitalcombatsimulator.com/en/files/3318555/

 

 

 

Edited October 8, 2021 by Draken35
removed file

[ataribaby]

Awesome idea and script. Thanks a lot. I am currently trying to learn follow Cat track.

Edited September 27, 2021 by ataribaby

[Yank]

Hi Draken35,

 

Could you please advise exactly where the Script and Sound files should go...  i wish to become a pathfinder but my computing skills are well below par.

 

Cheers

[ataribaby]

Yank, open demo mission and look at triggers. That's how you put sounds and scripts into mission. OFC you need create target trigger zones as well and put its selection somehow into oboe.lua instead user target selection via Other Radio menu. There is target table on top of script.

 

You will need at least basic LUA/generic scripting/programing skills to move this to your own missions.

 

Edited September 27, 2021 by ataribaby

[Yank]

I think ive goto you now.... will give this a go as been using Beacons for Huey CSAR misions and guess its the same principles.

[Draken35]

@Yank, put the scripts and sounds in the folders that you normally do and "touch" then in the triggers that @ataribaby showed . 

I have my Scripts and Sounds in folders under <DRIVE>:\Users\<USER>\Saved Games\DCS.openbeta...

 

Flying the Cat track is a lot harder that it seems... I bounce from short to long and back all the way to the target... I had to test the scrip with the Harrier (hey!, It was wearing RAF colours! And it kinda looks like a mosquito too  ) since my flying skills with the Mosquito are lacking... The closest bomb drop,while testing, that  I've got is a spread from 187ft to 354ft

 

For your own mission, you need to add your targets in the configuration section of the script:

 

If you add more than one target, the script will pick one during the trigger call to "Select Target" (which needs to be called, even if there is only one target)

Edited September 27, 2021 by Draken35

[Draken35]

Updated to version 1.03. Details at the first post.

[Draken35]

1.04 posted... Bug fixing, no new features 

(For some positions of Mouse, it was giving bomb release signals well outside the track)

[Retnek]

Wow - thx! That's exactly what I was hoping for!

Here's a first-hand WW2-report by a Mossie-navigator about Oboe-missions (pp 141):

Smith, Albert; Smith, Ian (2003): Mosquito pathfinder. A navigator's 90 ww2 bomber operations. Manchester: Crécy.

[Draken35]

2 hours ago, Retnek said:

Wow - thx! That's exactly what I was hoping for!

Here's a first-hand WW2-report by a Mossie-navigator about Oboe-missions (pp 141):

Smith, Albert; Smith, Ian (2003): Mosquito pathfinder. A navigator's 90 ww2 bomber operations. Manchester: Crécy.

Thanks!

 

I have this one in my reading queue:

https://www.amazon.com/Night-Flyer-Mosquito-Pathfinder-Operations-ebook/dp/B01H7UJ5TM/ref=sr_1_1?dchild=1&keywords=Mosquito+Pathfinder&qid=1633222632&s=books&sr=1-1

 

 

[Retnek]

On 10/3/2021 at 2:58 AM, Draken35 said:

Thanks!

 

I have this one in my reading queue:

https://www.amazon.com/Night-Flyer-Mosquito-Pathfinder-Operations-ebook/dp/B01H7UJ5TM/ref=sr_1_1?dchild=1&keywords=Mosquito+Pathfinder&qid=1633222632&s=books&sr=1-1

Good reading - bomber support mostly, good overview over 100 Group operations.

I very much hope there will be mods to simulate ground- and sky-markers. The Viggen-inventory has some nice flare bombs for target illumination - hopefully to modify and use as target-markers or even a kind of night-photo-flash? A lot of bomber-mission types should be available without the drop-snout, too.

Edited October 4, 2021 by Retnek

[Draken35]

1 hour ago, Retnek said:

Good reading - bomber support mostly, good overview over 100 Group operations.

I very much hope there will be mods to simulate ground- and sky-markers. The Viggen-inventory has some nice flare bombs for target illumination - hopefully to modify and use as target-markers or even a kind of night-photo-flash? A lot of bomber-mission types should be available without the drop-snout, too.

 

That would be cool... I've been thinking on how to make the AI (I'm a SP type of guy) target the place where I put the bombs... 

 

[Retnek]

Draken35 - from your read-me in "OBOE.txt"

"... Release heading. At the time of this writing, it is not clear to the author when the pilot should turn into the release heading but as a best guess, since it is calculated from the release point to  the target, is that the pilot should start turning into the release heading when the release signal starts. ..."

Smith & Smith (2003, c.a., p134) described the Oboe-training:

"... If the run was ultimately completed, the release signal - five dots and a two-and-a-half-second-dash - was transmitted three minutes after (signal) D. I would indicate the start of the seven-and-a-half-second release signal by a dramatic raising of my left arm in front of Johnny who hastily made any small adjustments of his heading to that given at briefing. ..."

Bold by me - I think that question is answered. Just 7 seconds to correct the heading AND set the plane back to level again! Those men really had to react on spot. What a pressure to do it right as a marker for a large raid. Failure means hundreds of bomb-loads wasted and maybe a number of air-crews killed for no or at least disappointing results.
As always with a bit of caution about details published 50 y later. But they describe THE critical phase of all the Oboe-missions. Both Mr. Smith show a great respect for details all the time - I see no reason not to trust them.

[Draken35]

@Retnek Thanks for that!!! The 5T (release signal) is only 3 seconds long currently)... I'll adjust it when I have a chance (have to change the sound and the duration in the script, since it is taken into account in the calculations) and will release v1.05 with that change.

 

They really where extraordinaire! The closest I've gotten in the demo mission is about 800 feet from the target... bouncing from long to short of track all the way since the intercept point.

 

This is gold: "five dots and a two-and-a-half-second-dash " !

Edited October 5, 2021 by Draken35

[Reflected]

On 10/5/2021 at 10:21 PM, Retnek said:

Bold by me - I think that question is answered. Just 7 seconds to correct the heading AND set the plane back to level again! Those men really had to react on spot. What a pressure to do it right as a marker for a large raid. Failure means hundreds of bomb-loads wasted and maybe a number of air-crews killed for no or at least disappointing results.
As always with a bit of caution about details published 50 y later. But they describe THE critical phase of all the Oboe-missions. Both Mr. Smith show a great respect for details all the time - I see no reason not to trust them.

 

I found another source on YouTube that specifically says that they stopped making course adjustments a few minutes before the release point and flew the briefed heading.

The part you quoted can be interpreted in a way that when the release signal started, they made absolutely sure the correct the heading to match the briefed one - that they had been flying for 3 minutes already.

Also, the pilot needed to confirm his estimated ground speed to the mouse station, so that they could calculate the exact release point. 7 seconds does not allow a lot of room for adjustments. Would make more sense to fly straight for 3 minutes and then the Mouse station transmits the release signal when they see fit. But this is just my own speculation.

 

It would be nice to find a definitive answer

 

 

[Draken35]

13 hours ago, Reflected said:

It would be nice to find a definitive answer

Yeah, that has been one of my problems while developing this: no clear "requirements" and too much open for interpretation... My other problem is lack of flying skills to accurately test the script   ... And a third problem I discover in the past few days is the weirdness of the magnetic variation in the channel map and the fact that we cannot get (afaik) the actual MagVar from DCS in lua.

 

Nice video... Haven't seen it before... Need to watch it again to digest it.

 

Version 1.05 is up. It has the 7.5 bomb release signal.

 

 

[Draken35]

So, that video says that a few minutes before release, the crew sends, by radio, their speed and the mouse operator calculates the final course and release point... Now, does that conversation happens in voice or morse? How long did those calculation took? I don't know, that "conversation and recalculations" seems to defeat the point of the prebriefed...

But, "forget" about flying the track and flying a prebriefed release course at a prebriefed speed and altitude (the video doesn't mention that the crew sends back its altitude to Mouse, seems like a very important omission) makes a lot of sense, and the 3 minutes point seems like ideal. Watcha think?

[Retnek]

15 hours ago, Reflected said:

 

I found another source on YouTube that specifically says that they stopped making course adjustments a few minutes before the release point and flew the briefed heading
 

Good find - thx.   I *know* I read a detailed description of the procedure in another's veteran report, too. Can't find it - grr!

Those 7 sec time for correcting the heading are really short with a good chance to screw it up ... so why taking such a risk? Good question, indeed. But turn it around. Flying a really long track precisely within 30 yards first. And then let the plane go straight & level for 3 min before the drop, without the remote reference? There's a big chance for large errors in those last 3 min, too.

You're right, this detail needs to be fixed - I'll try to find an answer. That's one of the most fascinating aspects of mission-building in flight-sims. You believe to understand what happened? Try to simulate it and you soon know what's missing.

[Draken35]

Just made a small modification in a test mission and added a heading from the 3 minutes mark to the target.... For this particular target, at 78nm from CAT, there is a difference of 5 degrees between the prebriefed release heading and the w3-target heading.... I think that would put it far enough from the release point over the track to prevent the Mouse to send the release signal... So, if the "few minutes before" is correct, then, the release point should be calculated over that vector and not over the track... The more I think about it, the "real" time corrections from mouse don't fit the system... But, of course, what do I know, I'm not a pathfinder or mouse/cat operator, wasn't there and didn't stay at a Holyday Inn last night....

 

[Retnek]

Another variant, this time without the final straight flight path:

" ... The Circle was made to go to one side of the Target, as the Bombs departed Tangentially when released from the Aircraft. Calculations depended on knowing the Height & Speed of the Aircraft, which, of course, the Pilot had to maintain dead Accurately. ..."

(https://masterbombercraig.wordpress.com/bomber-command-structure/no-8-pff-group-bomber-command/pathfinder-force-pff/pathfinder-methods/oboe/)

According to this the final heading correction offered a last chance to correct to the intended release-heading. If the pilot at that moment was in the process of correcting the plane back into the middle of the Oboe-track the error was just some yards. No problem to release with such a small error to the left or right. Releasing bombs when heading just a few degrees wrong would result in a *much* larger error.

Edited October 7, 2021 by Retnek
typo

[Draken35]

41 minutes ago, Retnek said:

" ... The Circle was made to go to one side of the Target, as the Bombs departed Tangentially when released from the Aircraft. Calculations depended on knowing the Height & Speed of the Aircraft, which, of course, the Pilot had to maintain dead Accurately. ..."
 

That actually made a lot of sense! It fits the KISS concept of flying mission while the complex part is done long before take off  ... I need to work out the math for that... I'll see what I can do 

 

[Reflected]

This tangential technique makes sense, BUT: it allows no room for adjustments depending on the estimated ground speed. You would need to alter the entire path to correct, wouldn't you?

 

Flying straight from the 3min point allows more time for deviation, but chances are you'll be within +/- 1 degree. This is what I currently use in my campaign mission, works quite well. But cross winds can make you drift despite holding the heading. So staying on the track longer is more accurate.

 

Correction only during the release signal is harder, but the starting point is much closer to the target, so less time to mess up, but easier to be off.

 

If I had to put together a reasonable version based on these, it would be this:

 

The path was calculated so that it allowed for a tangential bomb trajectory - but the pilots were briefed on the release heading (tangent) so they could correct when the release signal started. It's because they can be off this heading and still on the track momentarily.

 

How about this? Do you think it's reasonable?

[Draken35]

8 minutes ago, Reflected said:

The path was calculated so that it allowed for a tangential bomb trajectory - but the pilots were briefed on the release heading (tangent) so they could correct when the release signal started. It's because they can be off this heading and still on the track momentarily.

 

That is how I think it works. Matter of fact, I just had to do minor changes to my code to allow for that.

 

If the pilot is on the path then the correction (not considering wind) should be minimal if any... 

That's for a target at about 112nm and headings are tangential ... As you can see it is a 2-3 degrees per minute  (at that distance from Cat and Speed) , so, that 7.5 seconds release signal should be enough to get to the release heading, assuming a properly trained and competent pilot of course...  The key is flying the profile on the path (no surprises here). 

 

This is how it looks in the map:

The difference between the Cat-Target distance and the path radius doesn't see much.... Of course, that's assuming that my late evening math is correct... I'll test it over the weekend but if somebody volunteers to help testing I wouldn't complain  (pm me if interested)

 

@Reflected I'm actually curios to see how you implemented it with triggers! Looking forward to that campaign  and to the Huey one....

 

[Reflected]

OK, we have an agreement, then

 

I just changed my mission accordingly, and to be honest, I needed as much as 3-4 degrees of correction when I heard the release signal. So that's in accordance with the 'frantic correction' in the quote above.

 

Just because you're on the path doesn't mean you're on the right heading, far from it haha.

 

Out of curiosity, how wide is your path? Is it 105 feet like IRL?

[Draken35]

3-4 degrees? you are a hell of. lot better pilot than me!

 

I'm using 108ft, based on the FB mk VI wingspan .... I have options in the settings to make it wider, at the cost of accuracy...

 

And you are right, been on the path, could be crossing it perpendicularly!

 

This has been a very interesting conversation!