XM1156 Precision Guidance Kit (PGK)

Precision Guidance Kit (PGK), formerly known as Course Correcting Fuze (CCF), is a program that will enhance the accuracy at mid to max ranges of all 155-mm and 105-mm artillery projectiles. The Precision Guidance Kit (PGK) is a low cost fuze sized module that is used in lieu of a standard fuze on existing stockpile artillery projectiles to reduce ballistic delivery errors, improving artillery terminal effectiveness. The amount of improvement is dependent on the magnitude of the uncorrected errors and the error reduction capability of the PGK approach. PGK is a fuze-sized "module" that will have GPS to provide the location of the round and time during its flight while an inertial navigation system (INS) will determine the trajectory and continuously correct the round for increased accuracy.

PGK will be complementary to Excalibur, not a competitor. It will provide more efficient suppression vice the point precision of Excalibur. It will be a cost-effective way to improve the accuracy of the conventional cannon ammunition inventory without having to modify the projectiles.

The PGK is set by the Enhanced Portable Inductive Artillery Fuze Setter (EPIAFS). PGK is a guidance kit that replaces the standard HE burster fuze. It will compensate for probable error in range (PEr) and PE in deflection (PEd).

Without PGK, the CEP for conventional projectiles is a function of range. An M549A1 high-explosive rocket assisted (HERA) projectile fired at 30 kilometers has a 260-meter CEP. Rounds fired at shorter ranges usually have a CEP of 50 meters or less. PGK rounds fired at the mid-to-max ranges will be as accurate at 30 kilometers as rounds without PGK are when fired at five and 10 kilometers. CEP with PGK is no longer a function of range. In terms of the example M549A1, if it had PGK, its 260-meter CEP at 30 kilometers would shrink to 50 meters. In essence, PGK will shrink the miss distance, improve accuracy and result in better overall effectiveness and efficiency. It will ensure rounds impact on a target within their lethal radius, making conventional cannon artillery accurate at all ranges. The PGK program has three increments. The two follow-on increments will provide additional capabilities.

  • Increment 1's design will consist of a fuze-like kit that contains GPS guidance, power supply, control surfaces, electronic circuitry and the fuze function modes of point-detonating and proximity. The Increment 1 objective is to achieve a 50- meter or better CEP. In addition, the new M777A2 lightweight 155-mm howitzer and the M109A6 Paladin must be able to fire the PGK-equipped rounds. PGK also must be compatible with all 155-mm HE projectiles (M107, M795 and M549/A1) and the M203A1 and M232 modular artillery charge system (MACS).

  • Increment 2 will minimize GPS interference and jamming, improve delivery accuracy to 30 meters, add delay and GPS timefuze functions, and address the entire 155-mm family of platforms, munitions and propellants. The requirement for the second increment is for less than 30 m CEP for 155-mm cargo and high explosive projectiles.

  • Increment 3 adds the 105-mm family of platforms, munitions and propellants into the previous design. The reason for delaying the 105-mm variant is to synchronize it with the planned M119A2 howitzer digitization program. A long-range goal for Increment 3 is to leverage the 155-mm PGK technologies for PGK use with 105-mm projectiles. The initial version of PGK may be robust enough to meet the 105-mm howitzer requirements, but only time and testing will determine its compatibility. The requirement for the third increment is for less than 30 meters (threshold) and 10 meters (objective) CEP for all 155-mm and 105-mm projectiles.

    Forward observers (FOs) will be able to request PGMs as an option in future versions of the FO software (FOS) with new entries for target descriptions and target areas to help them determine the type of PGM for the mission. What PGK adds to PGMs is scalable precision. FOs will select PGK only when the mission dictates and circumstances meet the selection criteria established by the fire support cell (FSC).

    Selection criteria will be based on the commander's guidance and mission, enemy, terrain, troops and time (METTT) considerations. It may include factors such as maximum allowable target location error (TLE), target type, commander's intent, munitions availability, minimum acceptable range, conservation of UBL, operational environment, rules of engagement (ROE) or limitation on collateral damage.

    TLE is a measure of the accuracy with which a sensor can locate a target and is the difference between the actual and predicted target location. TLE can be extremely important to the effectiveness of a PGK fire mission. As with any conventional munition or PGM (Excalibur unitary or an M549A1 with PGK), the projectile will miss the target when given a "bad grid" as a result of poor target location. Because there is a relationship between CEP and TLE, there is an optimal TLE of between 30 and 100 meters for employing PGK to maximize lethality and reduce collateral damage risks. Sensor systems in the field today that can provide accurate target location to 10 meters or less are the second generation forward-looking infrared radar (FLIR) and fi re support sensor system (FS3). Sensors that have target location errors larger than 10 meters are the ground-vehicular laser locator designator (G/VLLD), first generation FLIR Bradley eyesafe laser rangefinder (BELRF) and lightweight laser designator rangefinder (LLDR).

    The Office of the Program Manager for Combat Ammunition Systems (CAS) issued a Sources Sought Notice [W15QKN-05-X-0840] on 08 August 2005 for information on Precision Guidance Kit (PGK) concepts for all calibers of cannon artillery projectiles. PGK refers to a kit that will improve the Army's artillery projectiles delivery accuracy. The PGK solution will improve the accuracy and thus effectiveness of conventional artillery munitions. The Army is interested in fielding a PGK capability as soon as possible. The purpose of the announcement was to obtain industry comments on the Army acquisition strategy. This announcement was to obtain industry's feedback on the willingness to participate in a cost sharing effort to the Army's proposed acquisition strategy.

    The Army intended to solicit, negotiate and award zero to two Technology Development (TD) awards on or about the January 2006 timeframe. This award would be followed by an option for a Systems Development and Demonstration (SD&D) phase and ceiling priced options for three (3) years of Production. A Technology Readiness Level (TRL) 6 demonstration would occur six months after award. TRL 6 is the System/subsystem or prototype demonstration in a relevant environment. The Army reserved the right to extend the TD phase of the contract 6-12 months should TRL 6 not be demonstrated. The Army expected to down select to one contractor based on demonstrated results. The selected contractor would enter a 18-30 month PGK SD&D Phase and subsequently three (3) years of production starting in FY08 (approximately 500-1000 kits in FY08, 7500 Kits in FY09 and 7500 Kits in FY10).

    It was the Government's intent to award Section 845 Other Transaction (OT) agreements with the contractors providing at least one third (1/3) of the total cost for the Increment 1 TD and SD&D phases of the program and transition to a FAR based contract for the Production phase. Initial awards will be only for the TD phase. The portions of the SOW dealing with the SD&D phase of the overall program will only be performed by the selected contractor at the end of the TD phase. The Army contemplates non-competitively awarding Increment 1 production options to the SD&D contractor based on demonstrated successful performance and affordable cost. It is anticipated that Increment 2 SD&D will start on/about 1 Oct 07 for 24 months followed by three years of production Increment 3 SD&D is anticipated to start on/about 01 October 2009 for 24 months followed by three years of production. The Army had limited funding and anticipated multiple awards for a performance period of seven (7) months.

    The Navy's Guidance Integrated Fuze (GIF) program was a PGK candidate and represented a cooperative Navy and Army effort to demonstrate, further develop and produce a fuze that will enhance the accuracy of the current artillery ammunition stockpile. GIF uses GPS guidance and small canards to apply minor corrections to the ballistic trajectory of artillery projectiles. The fuze applies in-flight corrections to deliver the round to the target with much greater accuracy. In addition to the Army and Navy cooperative GIF program, the Army planned to make multiple (if required) six-month technology demonstration awards in a parallel effort. PGK testing demonstrated consistent performance in predicted range and deflection. The GPS, control system and brake deployments functioned as designed. Additional testing achieved a precision of a 20-meter CEP versus a 55-meter CEP for the control rounds.

    As of early 2007 the Army was leveraging Navy Guidance Integrated Fuze technology. The munitions industry was aggressively investing research and development dollars to design this system. The Army continued to monitor the Navy's Pathfinder Program as a developmental risk mitigator. On Feb. 23, 2006, TRADOC approved the PGK Capability Development Document and forwarded it to HQDA for approval. PM CAS received five proposals from a request for proposal and conducted technical evaluations to determine which contractors to select for the technology development phase.

    The Raytheon PGK was designed to meet Army program requirements through a low-cost airbrake solution having minimal impact on round stability. Raytheon's solution focuses on meeting the PGK requirements at the lowest cost with the capability for incremental growth. Raytheon's PGK design leveragee production and flight proven subassemblies and an all-up kit that borrows heavily from M782 Multi-Option Fuze for Artillery (MOFA) and the Navy Guidance Integrated Fuze program. Hardware tests and six degrees of freedom simulation analysis indicate the Raytheon solution will meet the Army's PGK circular error probable requirement for both 155 mm and 105 mm artillery rounds.

    Raytheon Company successfully completed a gun firing test of its low-cost, XM1156 Precision Guidance Kit (PGK) solution at Picatinny Arsenal, NJ. 16 March 2006. The test firing, shot from the Picatinny Ballistic Rail Gun System, met all test objectives. The PGK successfully survived approximately 8,000 Gs (x gravity), the equivalent of a Modular Artillery Charge System 4 firing and the safety maximum given the mass of the test round. The PGK guidance electronics unit (GEU) successfully deployed the airbrake assembly immediately after muzzle exit. This live fire test culminated hardware-in-the-loop testing, 270 Hz laboratory deployment spin tests, 300 Hz live gun fire structural tests and integrated GEU rail-gun testing to 11,000 Gs. The Spearhead 1D Course Correcting Fuse (CCF) demonstration was a significant milestone for the team.

    A downselect in June 2006 cut Raytheon while BAE Systems and Alliant Techsystems were selected to undergo a so-called shootoff at Yuma Proving Ground, AZ.

    In July 2006 BAE Systems received a six-month contract from the U.S. Army's Project Manager, Combat Ammunition Systems, to participate in a competitive technical development program for the Precision Guidance Kit for use with Army cannon artillery ammunition. The BAE Systems-led team, which includes the company's Bofors unit, Rockwell Collins, and L3 Communications BT Fuze Products Division, received the award after successfully completing an internally funded project to demonstrate a two-directional precision guidance kit solution referred to as the BAE Systems Course Correcting Fuze (CCF). By April 2007 BAE Systems had successfully fired 20 GPS-guided rounds as part of interim testing for the U.S. Army's Precision Guidance Kit (PGK) Technical Development program. BAE Systems' PGK team fired 20 155 mm projectiles equipped with its PGK test modules at Yuma Proving Ground, Arizona. The interim tests were the second series of successful gun-fired tests completed by BAE Systems on its PGK solution in less than two months.

    In July 2006 Alliant Techsystems received one of two Technology Demonstration contracts from the U.S. Army Armament Research, Development and Engineering Center to develop a Precision Guidance Kit (PGK). ATK's industry team includes Rockwell Collins (NYSE:COL) and Draper Labs. Alliant Techsystems conducted a successful divert flight test of its low-cost Precision Guidance Kit (PGK) in January 2007. The PGK round was fired from a 155mm Howitzer at the Yuma Proving Grounds, Yuma, Arizona. The round maintained aerodynamic stability throughout its flight and demonstrated an in-flight divert capability well in excess of the company's design requirements for Increment 1, which is a 50 meter CEP. ATK's design features a fixed canard guidance package with gun- hardened electronics, a self-generated power supply, and a minimum number of moving parts. It is designed to not only meet, but exceed requirements for range, accuracy, and cost.

    On 18 May 2007 it was reported that US Army Joint Munitions and Lethality Life Cycle Management Command (JM&L LCMC) (Picatinny Arsenal, NJ) had awarded a system demonstration and development (SDD) contract to Alliant Techsystems to develop precision-guided artillery shells as part of an Army contract. Allliant will produce the XM1156 Precision Guidance Kit, a palm-size device that is screwed into a regular howitzer round to give it Global Positioning System capability. Terms of the 18-month contract, news of which was reported only in the Wall Street Journal, were not disclosed.

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