JPF fuze for JDAMs, ideas on how to implement it in BMS.

[macieksoft]

JPF is joint programmable fuze for JDAMs. It provides a nice option to program fuze from cockpit (CNTL page of JDAM, it is described in MLU M3 manual).
There are impact options, delayed option (with various delay times to choose from) and airburst option.

I have some ideas on how to implement its functions in BMS.

Well. In in impact option (no delay) JDAM would behave as normal.

With short delay damage modifier to the structures should be applied to increase damage (to simulate JDAM exploding inside building which certainly causes more damage than when it explodes when hitting the roof).
Also damage modifier should be applied to the vehicles, this should reduce damage a lot to simulate JDAM digging in the ground and exploding underground which would cause much less damage.

Second thing is airburst, this would simply increase damage to the light armor, infantry and so on and reduce damage to heavy armor and buildings.

The hard thing would be long delay (many minutes or even hours). This should be able to make JDAM work like area denial weapon. Enemies should avoid getting near unexploded JDAM, however i don’t know if it is possible to do it without extensive coding.

[Dee-Jay]

AFAIK, the fuse delay are set on the bomb itself (unless I am wrong, it is not set in cockpit ?) … but I’ve also thought about something like this when selecting the NOSE/TAIL fuse.

But for sure, your idea is VERY good and would increase the efficiency of the bomb depending on target type and effect to obtain.

To sumpup an easier approach (no need of data changes):

“Airburst” : less damage but wider range effect
Penetrator : less range effect but stronger damage effect

I LIKE it!

PS: not all bombs has nose fuse, most of GBUs and maybe JDAM do not have anymore nose fuse (replaced by the guidance kit). To be confirmed.

[macieksoft]

@Dee-Jay:

AFAIK, the fuse delay are set on the bomb itself (unless I am wrong, it is not set in cockpit ?) … but I’ve also thought about something like this when selecting the NOSE/TAIL fuse.
.

In JPF they can be set on bomb, but can also be set on cockpit (JDAM SMS CNTL page in F-16). I am 100% sure about this. It is described in JDAM manual for F/A-18 (google “JDAM manual”) and also in F-16 MLU M3 update manual (to download from our forum buddy @bluewolf webpagepage).

Burst option is a JDAM-only function that specifies the type of fuze function delay the
weapon should use and is applicable only with a JPF installed in the weapon. The burst option
is DTC loadable (see JDAM Target Data Set Profiles on page 101) and may be changed at
OSB 17 on the JDAM control page. Depressing OSB 17 on the JDAM control page will rotary
through the following burst options:
1. Air (AIR) - The weapon will function at the altitude set by the DSU-33 proximity
sensor.
2. Ground (GND) - The weapon applies the entered function delay (milliseconds).
3. Ground Delay (GND DLY) - Will cause the weapon to function at the entered
delay in hours after ground impact.
The burst option (OSB 17) will be blanked on the JDAM control page if the weapon is
not equipped with a JP F. The burst option fea ture is not di splayed on t he JDAM base pa ge.
The preferred fuze for the JDAM is the FMU-152B JPF, which is a smart fuze that
communicates digitally with the MMC on the 1760 serial digital interface. The FMU-152B
JPF arm time and function delay parameters are DTC-loadable and cockpit modifiable. Other
compatible fuzes for the JDAM include the FMU-139A/B, FMU-143/B, and DSU-33. Tables
7-2 and 7-3 summarize the JDAM fusing and data entry features.

And regarding nose fuzes from what i recall GP bomb based JDAMs (non LJDAM and non BLU109 based ones) has option to install noose fuze which can be in example proximity one. JPF can work together with it to offer airburst option,