Radar fix for Bx1 acts as a Nav fix

[Machalot]

I have been trying to use Bx1 to mark a popup target of opportunity for the BK90 and the RB04.  I do this by hitting the Bx button followed by 1, then T1 to start a radar fix, slew the cursor over the target, and TV to fix.  It places the Bx1 point on my target. 

 

Then as I approach the target I want to make adjustments.  However, it seems any further radar fixes I apply to Bx1 act as nav fixes like any other B point (the aircraft nav position is updated and all other waypoints move accordingly), rather than as a target refinements like for M points (where just the current point changes position).

 

Is this intended behavior? It really screws up navigation.

[Flappie]

100% reproducible. I'm not sure this is intended behavior.

Track attached.

 

 

AJS37_Bx1_fix_messes_with_nav_points.trk

[john4pap]

I think that bx1 to bx5 are nav fixes, whereas bx6 to bx9 are target fixes. So to my understanding, it is normal behaviour. I have noticed that bx9 generates a bug that messes up the the radar display indications (I can't remember in what way but it is consistent and reproducible). Bx6 to bx8 are fine though.

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[Scandfox]

Why not take a look in the manual .........??

 

For RB-15 You use Bx6,Bx7 and Bx8

 

For RB-04 You don,t use any Bx at all

 

DCS World\Mods\aircraft\AJS37\Doc

[Flappie]

49 minutes ago, Scandfox said:

Why not take a look in the manual .........??

Actually, we do read the manual.

Bx points 1 to 5 can be used as mark points.

 

Page 131 of RC2 manual:

 

Page 138:

 

Edited December 18, 2020 by Flappie

[Scandfox]

But not for RB15

[QuiGon]

48 minutes ago, Scandfox said:

But not for RB15

But you're the only one who talks about the RB15 here. No one said that they re used for RB15.

[Machalot]

3 hours ago, Scandfox said:

Why not take a look in the manual .........??

 

For RB-15 You use Bx6,Bx7 and Bx8

 

For RB-04 You don,t use any Bx at all

 

DCS World\Mods\aircraft\AJS37\Doc

The BK90 requires a waypoint of some kind, and it's not possible to create new B or M points from the radar, so I am trying to use Bx points. 

 

The RB04 doesn't need a waypoint to employ it, but I'm using a Bx mark point to keep track of the location of a pop up radar contact (e.g. ship), so I get nav and HUD indications to steer me back on target and get approximate range info after flying below the effective radar altitude or maneuvering evasive. 

[Scandfox]

On 12/17/2020 at 9:47 AM, Machalot said:

I have been trying to use Bx1 to mark a popup target of opportunity for the BK90 and the RB04.  I do this by hitting the Bx button followed by 1, then T1 to start a radar fix, slew the cursor over the target, and TV to fix.  It places the Bx1 point on my target. 

 

Then as I approach the target I want to make adjustments.  However, it seems any further radar fixes I apply to Bx1 act as nav fixes like any other B point (the aircraft nav position is updated and all other waypoints move accordingly), rather than as a target refinements like for M points (where just the current point changes position).

 

Is this intended behavior? It really screws up navigation.

I don't think it is a good idea to use BK90 to for pop-up targets and use Bx as target point.   You have to define target type for set-up release mode and you must define barometc pressure in target  for the best area of effect and use M as target.  Best is  Pre-Flight planning .

 

Thanks for info regarding the use of Bx guidance in multiple RB04 attacks......everyday you learn something..:)

 

 

 

 

 

 

 

 

Edited December 18, 2020 by Scandfox

[Machalot]

1 hour ago, Scandfox said:

I don't think it is a good idea to use BK90 to for pop-up targets and use Bx as target point.   You have to define target type for set-up release mode and you must define barometc pressure in target  for the best area of effect and use M as target.  Best is  Pre-Flight planning .

I agree, preflight planning is best.  But targets don't always cooperate and often surprise you, so it's not always possible to have a preplanned point near the area you need to bomb ("near" meaning an M point is visible on radar so you can slew it to the desired target).

 

What do you mean by "define target type for set-up release mode"?  I know about the long, wide, and compact settings using TAKT 921, 922, and 923, but that can easily be set in flight.

 

I thought the BK90 uses a radar altimeter, so a correct target QFE setting is helpful but not strictly required.

[Machalot]

11 hours ago, john4pap said:

I think that bx1 to bx5 are nav fixes, whereas bx6 to bx9 are target fixes.

Yes, according to the excerpt of the manual posted by Flappie, they are intended for reconnaissance. To me it's not clear whether that means they should provide fixes. But it seems you are correct about what is actually modeled. 

[john4pap]

Yes, according to the excerpt of the manual posted by Flappie, they are intended for reconnaissance. To me it's not clear whether that means they should provide fixes. But it seems you are correct about what is actually modeled. 

I am not at home and don't have the manual on me but I'm fairly confident bx1 to bx5 are for navigation and not reconnaissance. So it makes sense that you preprogramme those waypoints for getting fixes from locations on the map that stand out on your radar but aren't part of your flight plan. I don't think you're supposed to create a new bx1 to bx5 waypoint using your radar while flying. You preprogramme them and then get a fix if and when needed.

Now on a different scenario, say that you see an enemy's location and want to mark it: use bx6 to bx8 (bx9 acts weirdly) to mark it with your radar. They just mark the location of the target and don't affect navigation.

The manual is indeed quite ambiguous on some points, but this sounds straightforward to me.

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[Scandfox]

Regarding BK90 You can set approach altitude up to 500 m barometic altitude in approach phase then in attack the BK90 uses Radio height,,

91500 in TAKT is 500 m Barometic Height then in 5 km from target attack height is 60 m radio Height

Edited December 18, 2020 by Scandfox

[DarkStar79]

Yes, according to the excerpt of the manual posted by Flappie, they are intended for reconnaissance. To me it's not clear whether that means they should provide fixes. But it seems you are correct about what is actually modeled. 

If you want to mark pop up target. You really should use the SPA mode.

In that mode you can just mark the targets, you press one of the T buttons (same as when you make a navfix).

I often use that tactic, when you fly over the target you make a fix, and mark the target.

And when you press the the numpad numbers it will bring up that target, and it will be shown on the radar.


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[ftmch]

Are you able to then attack a target you've marked in SPA mode?

[DarkStar79]

Yes you are. It saves that position


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[Machalot]

On 12/24/2020 at 4:48 PM, DarkStar79 said:

If you want to mark pop up target. You really should use the SPA mode.

In that mode you can just mark the targets, you press one of the T buttons (same as when you make a navfix).

I often use that tactic, when you fly over the target you make a fix, and mark the target.

And when you press the the numpad numbers it will bring up that target, and it will be shown on the radar.


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How do the waypoints you designate in SPA behave when you do radar fixes on them?  Do they provide nav updates like B points or do they reassign the target point like M points? 

Edited March 29, 2021 by Machalot
N -> B

[Flappie]

They have their own SPA waypoints: M1, M2, M3... for MAL waypoints (to locate a ship), and S1, S2, S3... for SKU waypoints (to determine course and speed of ship).

If you want a quick glimpse, replay tracks attached here.

[ftmch]

Awesome, if you just switch back to ANF from SPA you can attack the fix you had selected in SPA mode, though the manual doesn't actually say that you can do this.