GDR 99 - Weapons Systems

SADARM:
Smart Submunition


Section Articles
• A New Generation of Mortar • Expert Combination: Krauss-Maffei • The Defence Supermarket • Making Tracks: the FCS/Tracer • Centre of Excellence: Mauser • Big Guns Given Greater Mobility • Man With a Plan: Herstal • On Top of the Action: Delco • Crusader on Target in 1999 • Special Application Rifles • Fuchs Fuses for Fighting Forces • Revolutionary: the OICW • Revolution in US Small Arms • SADARM: Smart Submunition
Top: Two SADARM submunitions are delivered by one 155mm projectile

Aerojet is under contract with the US Army to develop a product improved SADARM that will enhance the effectiveness of the submunition and also reduce costs. John Clinton reports.

SADARM is a fire-and-forget, top-down-attack, multi-sensor, smart submunition for use in 155mm artillery and other carriers such as MLRS. Multiple sensors mean SADARM is highly countermeasure-resistant. The SADARM round is referred to as a 'wooden' round because no maintenance is required.

The main SADARM components are the three sensors utilised for target detection, (active and passive millimetre wave radar and infrared), the explosively formed penetrator, and the two parachute assemblies (a ram air- inflation device and a vortex ring parachute). The IR builds a full image of the target and is the preferred aiming sensor. The MMW is utilised to sense metallic and man-made objects and is the alternate aiming sensor. SADARM uses sensor fusion from all three sensors that operate simultaneously to accurately distinguish real targets from decoys.

SADARM's two-scan algorithm, used in confirming the target, gives further confidence in discriminating between real and false targets. Once a target is detected, a firing command is issued that fires the explosively formed penetrator. SADARM is lethal. It has been demonstrated to defeat all known armour on the battlefield.

From Arizona to Alaska
Initial production testing commenced in May 1997 and ran through to November 1997. Tests were conducted for the explicit purpose of testing actual production submunitions against various target sets in varying climatic conditions and geographic locations: Yuma, Arizona, in desert conditions; and Ft Greely, Alaska, in summer and winter conditions.

Present plans call for the production of 50,000 projectiles for the US Army. Delivery of SADARM to US Army forces will improve warfighting effectiveness substantially and bring about significant reductions in artillery logistics. Figure 2 depicts these points in comparing SADARM to dual-purpose improved conventional munitions.

Aerojet also is under contract with the US Army to develop a product improved (PI) SADARM that will enhance its performance in terms of effectiveness and cost. The programme is a 48-month, $48 million contract with the US Army that was awarded in February 1997. The programme's objective is to increase effectiveness by 30 per cent over the baseline SADARM requirement by tripling the area over which the submunition will search for targets. The design strategy for PI SADARM is to focus on high pay-off features that will significantly improve its effectiveness without changing the hardware.

The PI version of SADARM

Below: SADARM has two parachute assemblies - a ram air-inflation device and a vortex ring parachute


Link: www.aerojet.com

To achieve a 30 per cent increase in effectiveness, the PI version will focus on improving the probability of encounter by two simple changes. First, the submunition will commence its target search at a higher altitude, and second, it will change the hang angle at which it is suspended from the vortex ring parachute in order to scan a larger area. Because of the larger area being scanned by the sensors, the IR sensor and the processing electronics will be upgraded. Electronics have evolved rapidly in recent years and the processing capabilities have improved exponentially over those incorporated originally in the basic SADARM. All other subsystems remain the same as baseline SADARM. The programme is scheduled to be cut into the production line in FY01, with deliveries to the US Army commencing in FY02. The US Army intends to procure 1,000 rounds of the baseline SADARM with the remaining 49,000 rounds to be the PI SADARM.

PI SADARM will incorporate commercial off-the-shelf (COTS) technology that will reduce the overall cost of the submunition. It also will incorporate the ability to re-programme the submunition for targeting and aiming algorithm updates and jammer/countermeasure updates. This tactically important feature also protects a buyer's investment in a submunition because it will not become obsolete over the course of its life.

PI SADARM will provide the effectiveness necessary for operational use in platforms such as Crusader and MLRS where, because of increased ranges and delivery errors, a larger search footprint is required. It will provide the US Army with a capability for use in its present systems (M-109/M-198) and provide a submunition that is readily adaptable to growth platforms such as Crusader with the XM-982 projectile and MLRS.