OVERVIEW: The GBU-54(V)1/B Laser Joint Direct Attack Munition (LJDAM) is an inertial and laser-guided, GPS-aided, glide bomb using a bolt-on guidance and aerodynamic package mated to a MPR-500 500 pound Penetrating bomb intended for use in urban environments/low collateral damage situations or against fortified targets.

DETAILS: LJDAM is intended to provide accurate delivery of general purpose bombs in adverse weather conditions.  The GBU-54(V)1/B differs from other JDAM versions by incorporating an laser terminal seeker. 

Before take off, mission plans including release envelope, target coordinates and weapon terminal parameters are loaded to the host aircraft prior to take off.  Before release,   INS alignment and targeting data and is automatically loaded to the weapon. 

Like the JDAM, LJDAM can be a "fire-and-forget" weapon system.  Once released, the bomb's INS/GPS guides the bomb to the target, allowing the launching aircraft to take evasive action without having to guide the weapon.  The INS is capable of guiding the JDAM to target independently of the GPS, albeit at a reduced accuracy.  However, for the enhanced accuracy provided by the laser seeker, the target must be illuminated by either a laser on the launching aircraft or "buddy-lasing" from another platform. This enhanced targeting capability is reduced  in adverse weather conditions or if the lasing platform must maneuver.

The LJDAM can be launched from very low to very high altitude and can be launched in a dive, toss, loft or in straight and level flight with an on-axis.  Off-axis delivery is also possible, albeit with a decrease in bomb range. LJDAM also allows multiple target engagements on a single pass delivery.



Specifications: 

Weight: 		254kg
Length: 		2.352m
Wingspan:		0.356m
Speed:			 unkn knts 
Range:			13.0 nm (altitude dependent)
Accuracy:		CEP:  2 meters with laser; 30 meters using only 				inertial
Penetration:		1 meter reinforced concrete or 4 200mm thick floors


NOTES:  IOC 2012. Officially, the GPS-enhanced CEP of the weapon is cited as 13 meters.  However, according to Jane's, accuracy is reportedly approximately 14m (INS only) and 8 meters (INS+GPS).  
 
 
 
SOURCES: IHS. "GBU-31, GBU-32 and GBU-38 Joint Direct Attack Munition (JDAM)." Jane's Air-Launched Weapons, Feburary 2015;  "Joint Direct Attack Munition (JDAM) GBU-31 - Smart Weapons." Federation Of American Scientists. Accessed December 29, 2019. https://fas.org/man/dod-101/sys/smart/jdam.htm ; "Boeing JDAM." Designation-Systems.Net. Last modified August 21, 2008. http://www.designation-systems.net/dusrm/app5/jdam.html; Boeing, "Laser JDAM," https://www.boeing.com/resources/boeingdotcom/defense/weapons-weapons/images/laser_jadam_product_card.pdf; IMI Systems. "MPR-500." IMI Systems. Accessed December 31, 2019. http://www.imisystems.com/wp-content/uploads/2017/01/mpr500.pdf.