Using the INS for precission bombing

[Azrayen]

Télémétrie Air Sol

 

Radio Sonde

[Lorenzo.D]

There is a videotutorial on youtube?

 

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[kobeshow]

There is a videotutorial on youtube?

 

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I don't think there is since there are still some kinks to work out, it kind of works right now but you can hardly call it "precision bombing" (;

[jojo]

I don't think there is since there are still some kinks to work out, it kind of works right now but you can hardly call it "precision bombing" (;

 

Indeed, the idea behind IP attack isn't accuracy but "stand off" range :thumbup:

(from small arm fire, AAA, MANPAD)

[vparez]

:thumbup: @Azrayen

[fjacobsen]

It will never be precision bombing when using freefall bombs.

 

INS bombing will only make it possible to do some kind of blind bombing In bad weather, otherwise using CCIP or CCRP will be as accurate.

 

For ude wit Laser guided bombs it´s a different matter, since that way You can drop the bombs at the right point with no visual cues on the ground.

[dotChuckles]

It will never be precision bombing when using freefall bombs.

 

INS bombing will only make it possible to do some kind of blind bombing In bad weather, otherwise using CCIP or CCRP will be as accurate.

 

For ude wit Laser guided bombs it´s a different matter, since that way You can drop the bombs at the right point with no visual cues on the ground.

 

I don't think this isn't actually the case. INS/RADAR offset bombing was one of the primary methods in the Tornado GR.1 for low level loft profile delivery. While the mirage uses a visual system for updating the IP offset as opposed to a ground scanning radar and a cursor, the principle is essentially the same. The Navigator in the tornado updated the offset by cursor hooking a known feature to update the offset, in the M2000C you do it visually with a HUD cursor.

 

This method was accurate enough to put a grouping of bombs on a building, taxiway junction or aircraft on the ground when performed correctly. We are talking precise to within meters as opposed to inches, but that was pretty accurate for the 70's and got the job done when it was four 1000lb bombs. Remember, precision bombing is a relative term depending on what decade you're talking about ;-) but even by today's standards it was pretty good.

 

If you want to read a good account of the method, even though the raid went pear shaped, John Peters/Nichols book "Tornado Down" describes it and it's capability very well. A worthwhile read on it's own too.

 

The loft attack at 20:00 is all driven by INS and offsets, some nice shots of the symbology there too. A lovely film and worth watching for the nostalgia :-)

 

Edited October 3, 2016 by dotChuckles

[Frederf]

Does anyone know what ZBI (ZB1?) stands for? Is it only used with PI?

[ZHeN]

very cool video, dotChuckles

Tornado reminds of our vintage Su-24M - it was also highly accurate for it's era (and now too !)

 

does anyone have video tutorial of INS updating in Mirage 2000C ?

[jojo]

Does anyone know what ZBI (ZB1?) stands for? Is it only used with PI?

 

By convention, in French abbreviation "Z" is altitude.

BI stands for "Baro Inertiel".

[Lorenzo.D]

There is a tutorial or general document for this tipe of offset bombardament?

 

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[Zeus67]

There is a tutorial or general document for this tipe of offset bombardament?

 

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Not yet. I will make a video this weekend.

[fjacobsen]

Any news on the video or more detailed explanation ?

[Binary]

This is great! I was able to use JTAC coordinates as the IP and the JTAC successfully guided the GBU-12 to the intended destination. However, I am wondering why this approach requires an offset waypoint? Because having to setup an offset (even though it is just a value of about 0,001 degree) to get it to work, fells kinda wrong? Don't get me wrong, I don't want to complain, I am just interested into the "why". Thanks

[jojo]

This is great! I was able to use JTAC coordinates as the IP and the JTAC successfully guided the GBU-12 to the intended destination. However, I am wondering why this approach requires an offset waypoint? Because having to setup an offset (even though it is just a value of about 0,001 degree) to get it to work, fells kinda wrong? Don't get me wrong, I don't want to complain, I am just interested into the "why". Thanks

 

 

Think of a time when there was no GPS, no data link. Just a guy on the ground, with his map and his compass talking to you on the radio.

 

Range and bearing from a known point is a very common way to guide fire in the Army, Air Force and Navy.

[ZHeN]

a known point

if the guy on the ground knows his lat/lon coords, why is it such a big deal for him to find out target's coords ?

[jojo]

if the guy on the ground knows his lat/lon coords, why is it such a big deal for him to find out target's coords ?

 

Just by reading on a map ?

 

I think it's just easier and quicker with range & bearing.

[kobeshow]

Having an offset waypoint to the IP is also good for tactical reasons, if the bombers always fly from the IP to the target and then back to the IP and back to the target it is easier for CAP to cover them as they know exactly which corridor they will use for the bombing runs, staying in that corridor can also serve as protection from known SAM sites.

[ZHeN]

Just by reading on a map ?

 

I think it's just easier and quicker with range & bearing.

 

yea, but still it is odd M2K's weapons management system lacks this ability - to bomb right at coords, not offset to them

[dotChuckles]

This is great! I was able to use JTAC coordinates as the IP and the JTAC successfully guided the GBU-12 to the intended destination. However, I am wondering why this approach requires an offset waypoint? Because having to setup an offset (even though it is just a value of about 0,001 degree) to get it to work, fells kinda wrong? Don't get me wrong, I don't want to complain, I am just interested into the "why". Thanks

 

So as other people have said, this system and aircraft really dates to before GPS was a common thing and the INS system had no external reference and was subject to drift. The offset was selected in mission planning to be a geographical feature. You're now flying your attack, and can pinpoint from your plane of reference either using ground radar in some aircraft or visually in the M2000C the geographical feature. This updates or "cancelling your offset" so that your INS and position are exactly aligned. Now you have a fixed bearing and distance to your target that is very accurate. The use of the offset IP means that this procedure is done before you are committed to attacking the target.

 

Imagine trying to update your INS, correct for INS drift, fly an attack profile and then release weapons all while having incoming fire... all at the same time. The offset lets you do that on the run-in, which also allows you to use standoff tactics like loft bombing too.

 

All of this would be done in mission planning, IP offset bombing was never meat to be used as a CAS attack method. Really only for planned targets.

[jojo]

Yes, the weapon system is designed to deliver unguided AG weapons, at a time when there was no GPS but only drifting INS.

Moreover we are talking about an air defense fighter. AG was a secondary role.

 

What seems obvious today with modern technology wasn't the same back then.

 

And even today, GBU are released like unguided bomb.

 

BTW the title of this topic is misleading, IP attack isn't about "precision bombing", it's about releasing from (limited) stand off range despite low level ingress.

Edited October 12, 2016 by jojo

[zaelu]

You need to set up a "BAD" in PCN.

 

So the "DEST" waypoint will be the IP and the "BAD" the target.

 

How exactly do you do that? I think some steps are missing from first post.

 

Zeus added these info:

 

To create an offset (BAD) for WP3 you must:

 

1. Set PREP to 03

2. Enter either ΔL/ΔG or ρ/θ

3. Enter ΔALT.

 

To activate the WP3 offset, you must:

 

1. Set DEST to 03

2. Click on the BAD button in the PCN.

 

Is this all?

Edited October 15, 2016 by zaelu

[CallsignFrosty]

So is the radar INS update borked at the moment or am I doing it wrong?

[jojo]

How exactly do you do that? I think some steps are missing from first post.

 

Zeus added these info:

 

 

 

Is this all?

 

Follow Zeus data to enter the BAD in PCN.

Then 2 possibilities:

- you just want to go to BAD = hit "BAD" on PCN, and the NAV system will guide you

- "BAD" is a target you want to attack = make all your attack preparation, and select "PI" on PCA. You will have to designate the DEST waypoint to perform NAV update (the same as OBL) then the system will guide you to "BAD" to attack.

 

The PI option should be displayed on PCN only if a BAD is available for selected DEST waypoint.

[zaelu]

I followed the instructions but I had no PI on PCA to press.

 

I think at the end of the process some little buttons needs to be pressed in PCN and it has to be clear what and why.

 

You say "you just want to go to BAD" but I understood that it's impossible as you need to pass your waypoint first and to the update before anything.

 

Because of this what you say above doesn't make click in my head at this hour (it could be that I didn't finished my coffee :D ).