Counter Rocket, Artillery, and Mortar

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Israeli Iron Dome air defense and C-RAM system.
2010 test-fire of a C-RAM. Balad, Iraq

Counter Rocket, Artillery, and Mortar, abbreviated C-RAM or Counter-RAM, is a set of systems used to detect and/or destroy incoming: rockets, artillery, and mortar rounds in the air before they hit their ground targets, or simply provide early warning.

The intercept capability of C-RAM is effectively a land version of weapons such as the Phalanx CIWS radar-controlled rapid-fire gun for close in protection of vessels from missiles; the weapon system also contains a Forward-looking infrared (FLIR) camera to allow a Soldier to visually identify these target threats before engaging the targets. One major difference, however between the land- and sea-based variants is the choice of ammunition. Whereas naval Phalanx systems fire tungsten armor-piercing rounds, the C-RAM uses the 20 mm HEIT-SD (High-Explosive Incendiary Tracer, Self-Destruct) ammunition, originally developed for the M163 Vulcan Air Defense System. These rounds explode on impact with the target, or on tracer burnout, thereby greatly reducing the risk of collateral damage from rounds that fail to hit their target.

Description[edit]

C-RAM is an initiative taken in response to an operational needs statement made by the Multinational Force Iraq (MNF-I). The directive arose in response to the increasing number of casualties caused by attacks using rockets, artillery, and mortars in Iraq. The land-based Phalanx B (also known as the Land-based Phalanx Weapon System-LPWS) was subsequently deployed in Iraq in the summer of 2004. It protected the Green Zone and Camp Victory in Baghdad, Joint Base Balad near Balad, Iraq, and by the British Army in southern Iraq. In 2012 the LPWS radar directed gun systems were deployed to Bagram Airfield in Afghanistan.

General Interest-Sensors[edit]

FOB Salerno in Afghanistan is known as rocket alley. On that FOB C-RAM had AN/TPQ-48 radars (Lightweight Counter Mortar Radar-LCMR) and the long range AN/TPQ-37 radar(s). The Taliban were firing long range rockets out of Pakistan onto Salerno. A 122 mm rocket was detected by a Q37 radar from a known area of interest. C-RAM was setup where it took at least two sensors to sound an alarm (confirm a possible rocket track); however the operator has the option to manually confirm incoming rockets. Based on an input state vector from the radar, the C2 terminal (Forward Area Air Defense-FAAD) coasted the 122 mm rocket track (for about twenty seconds to the predicted point-of- impact). The operator asked the Battle Captain if he could confirm the track; he said no. Well the low power Q48s never sent a state vector to FAAD. The rocket slammed onto the FOB killing a Lt. from TX. That is a no warn event. Since the rocket came from an area of interest and will impact the FOB he should have had permission to manually confirm this track.

When C-RAM first went into Afghanistan the following radars were fielded to the units: Q48 radars, AN/TPQ-53 (two radars) and Q37 radars on the FOBs. Then the AN/TPQ-49 (LCMR) replaced the Q48 radars. However, the program office had a hard time maintaining the Q49 radars on the FOBs-Logistics problem. Within three months 22% of the installed radars were NMC (non-mission capable). The problem was the operators on the FOBs were to provide basic maintenance. However they only had 4 days training on the old Q48 radars. Moreover there was limited (inadequate-blade antennas) spare parts and no depot support. Solution: Give the Q49 radars to the Marines and field the Ku band MFRFS (Ku Band Multi-Function RF System) radar to the units on the FOBs. Note that the primary reason for developing and fielding the Raytheon MFRFS radar was to counter the current threat in Afghanistan; that is the short range low Quadrant Elevation-QE 107 mm rocket.

The MFRFS radar is a medium PRF (Pulse Repetition Frequency) four quadrate track while scan phased array radar covering the full 360 degrees. Each quadrate scans a narrow elevation sector just above the horizon providing early warning of launched ballistic targets. The volume coverage and frame time are defined by the beamwidth of the fan beam and the vertical velocity of targets, respectively; furthermore, based on field data from radars deployed in Afghanistan, its calculated reliability MTBF (Mean Time Between Failures) is 425 hours-all of the observed failures were hardware.

Finally, the development of the Ku Band MFRFS system is based heavily upon Raytheon's technology originally developed under the Army's Future Combat Systems (FCS) program. Raytheon engineers developed, tested, and fielded a Low Quadrant Elevation MFRFS C-RAM system in only 14 months, using some residual assets from FCS. Currently this Ku band pulse-Doppler radar is deployed in Afghanistan (every FOB), Iraq and the joint FOB in the Sinai.

LPWS[edit]

The LPWS is only about 30 percent effective in destroying rockets and mortars. Another issue is the very limited range of the gun; mainly a point defense centered within a small defended area. In addition this system is a Logistics nightmare. In the beginning C-RAM had a difficult time maintaining readiness (Operational Availability in the mid nineties) of all gun systems in Iraq. Namely, at first certain people in Logistics did not want to admit there was readiness problem. It took about one year for upper management "to get on the stick". Initially, they in the program office had no demand history of spare parts or tried to create one. Note spares analysis using reliability was completed and was used with some success. Component Reliability: Total operating time per systems components divided by the number of failures for that component. Time terminated test.

Certain fielded LPWS systems on the FOBs had back power issues. The maintainers on the FOBs thought it was due to external radiation. Back power will shut off the transmitter to prevent damage to the Ku band Tube; this became a big issue for a couple of years. The origin of the back power was internal to the radar. High VSWR. Both these back power issues and BIT (Built-In Test) false alarms that occurred with these guns were quickly cleared by the operators on the FOBs. That is by taking the gun system to standby and then up again can clear these faults within two minutes. Note these faults were not used to calculate the LPWS reliability. The LPWS Logistics MTBF (late 2009 time frame) is 356 hours. Moreover, in Iraq (early 2008) the Mean Time To Restore (Mean Time To Repair plus Logistics delays) a gun system was 8.6 hours. What drove this time to repair was the Logistics delays; that is if the part was not in Theater it came from Louisville Ky-24+ hours delay; but by early 2009 the mean time to restore a Gun system came down where the Operational Availability for each LPWS was in the mid nineties; this excellent readiness carried through to Afghanistan.

Definition: Reliability parameters fall under two categories:

1) Mission Reliability. The measure of the ability of an item to perform its required function for the duration of a specified mission profile, defined as the probability that the system will not fail to complete the mission, considering all possible redundant modes of operation. The metric Mean Time Between System Aborts (MTBSA) defines mission reliability. MTBSA = Total Operating time/total failures both software and hardware.

2) Logistics Reliability (hardware reliability). The measure of the ability of an item to operate without placing a demand on the logistics support structure for repair or adjustment, including all failures to the system and maintenance demand as a result of system operations.

Rafael Counter Rocket, Artillery, and Mortar (C-RAM) and Very Short Range Air Defense system (V-SHORAD) at static display Aero India 2013

RAM Warn[edit]

The RAM warn system fielded in Iraq and Afghanistan is WAVES (Eaton's Wide-Area Mass Notification System). WAVES uses outdoor speaker towers-with an Integrated Base Station (C2 terminal)- covering a wide-area via wireless radios to sound alerting messages (between 5 to 10 seconds warning before impact-ideal) . An issue with this system is that it operates in the 2.4 GHz wireless band. In Iraq C-RAM had some interference issues with this system on the FOBs. A work around was RF over fiber; namely fiber interconnecting the WAVES towers; the final solution was a completely new system operating in the 5 GHz band. This new Northrop Grumman system uses mesh radios (a wireless mesh network of warning towers where each radio routes the packets based on a network address and routing metric) from Rajant with NSA Suite B authenticated encryption; note that the C2 terminal for this warn system is FAAD. Lastly, PM C-RAM is currently fielding this Northrop Grumman system to the units.

Moreover NSA supports two commercial authenticated encryption protocols- Suite B (AES Galois Counter Mode) and CCMP (threshold protocol). Both of these use AES for encryption and the CTR mode (counter mode) of operation. An issue with CTR mode is that it changes a block encryption to a stream encryption. Namely, AES encryption acts as a random number generator for stream encryption of the data. Note: NSA Suite B recommends using AES with 256 bits of encryption key. The main issue however with all encryption is key management and generation. Reading NIST (National Institute of Standards and Technology) documents do not bring these issues "home". Lastly, a couple of years ago NSA recommended not using its Suite B protocols.

Experimental-PM C-RAM's Iron Dome[edit]

PM C-RAM developed and successfully tested (Summer 2013) a system similar to Iron Dome. It was the Accelerated Improved Intercept Initiative program - known as AI3.

The AI3 Battle system includes the Raytheon Ku Radio Frequency System Fire Control Radar, an Avenger-based AI3 launcher, a C-RAM command and control, Technical Fire Control, and the Raytheon AI3 interceptor missile. The AI3 interceptor was initially guided on inflight radio frequency data link updated from the Ku RF Sensor radar, which was tracking the inbound rocket target. The interceptor then transitioned to terminal guidance using its inboard seeker and illumination from the radar to guide the missile (Proportional Navigation) to the target. Using an RF proximity fuze to determine optimal detonation time, the missile calculated its burst time and intercept time to the target. This system will not be placed on a FOB!

Comment:The basis of Proportional Navigation was first discovered at sea, and was used by navigators on ships to avoid collisions. Commonly referred to as Constant Bearing Decreasing Range (CBDR), the concept continues to prove very useful for conning officers (the person in control of navigating the vessel at any point in time) because CBDR will result in a collision or near miss if action is not taken by one of the two vessels involved. Simply altering course until a change in bearing (obtained by compass sighting) occurs, will provide some assurance of avoidance of collision.

PM C-RAM will be fielding the following systems to the units: Sensors AN/TPQ-50 (LCMR) and AN/TPQ-53 radars, Intercept LPWS and the new RAM warn system using the Rajant mesh radios (named Huntsman radios). When deployed on the FOB the sensors, the LPWS Gun systems and the RAM warn towers are all on separate networks; specifically the Guns use fiber while the sensors connect to FAAD via a separate wireless network. Northrop Grumman of Huntsville Alabama has the mission to integrate this equipment on the FOBs.

AN/TPQ-50[edit]

The Q50 LCMR program of record, which emerged out of a quick reaction capability [QRC] effort to quickly deploy radar able to protect forward-deployed forces on the move, has greater range capabilities and is more accurate than previous models of the technology, the Q48 and Q49 LCMRs. The SRCTec LCMR family consists of the Q49 and Q50. QRCs represent efforts to quickly get capability-enhancing technology to theater while simultaneously harvesting Soldier input and refining requirements for a traditional program of record.

One of the major differences between Q50, and earlier versions is the accuracy of ‘point-of-origin.’ Earlier versions-Q49 and earlier-had in the neighborhood of 100-meter location accuracy, which-for situational awareness and understanding-is good. But in terms of being sufficient to go after with an indirect-fire system-for example, a cannon-it was probably on the edge of whether or not to respond with indirect fire because of that error in detection capability. One of the requirements with the Q50 is to improve that ‘point of location’ accuracy to where it is-counter-fire quality.

AN/TPQ-53[edit]

The Lockheed Martin Q53 radars will replace the aging AN/TPQ-36 and Q37 medium-range radars now in the Army's inventory. In addition to its counter-fire and counter-drone missions, this radar now has a short range air defense mode. Finally the Army Test and Evaluation Command-June 2015 report details the testing of this S-band radar. Three interesting results from this report are its reliability, the point-of-impact errors and false targets generated by the radar:

1) The radar did not meet its reliability requirement. The Army requires an 80 percent confidence that the average time between system aborts is greater than 185 hours. With eight failures in 500 hours, the achieved MTBSA was 62.5 hours with an 80 percent confidence interval of 38 to l07 hours. The Army developed a new requirement of 91 hours MTBSA and the updated requirement is in joint staffing. Note that three of the eight failures were hardware related. The Logistics MTBF is 167 hours with an 80 percent confidence interval of 75 to 454 hours; but based upon field data PM C-RAM obtained 320 hours for the radar's hardware reliability; note that this is within the confidence interval.

Comments: The one issue with this reliability test is its short duration, i.e., 500 hours. The 91 hours came from the reliability analysis of Q53 field data for two systems in Afghanistan. For all fielded systems, PM C-RAM gets daily maintenance reports.

2) The point-of-impact error assesses the radar's ability to identify the point-of-impact of the detected projectile, and is used to warn troops of incoming projectiles and prioritize counter-fire missions. Threat missions affecting near-friendly units are given a higher counter-fire priority. The accuracy of the point-of-impact estimate is not as critical, since knowing a general location of the impact suffices for both warnings and prioritizing counter-fire missions. For rockets and mortars the point-of-impact errors (Circular Error Probability) are over one hundred meters.

Comments: This error could cause several RAM warn tower sectors to simultaneously sound an alert. In the military science of ballistics, circular error probable (CEP) (also circular error probability or circle of equal probability) is a measure of a weapon system's precision. It is defined as the radius of a circle, centered on the mean, whose boundary is expected to include the landing points of 50% of the rounds

3) The radar will report false targets when no projectiles are in the search area. A false target occurs when the radar determines that a threat weapon is firing, when none is present. The radar may do this when there is nothing known in the air, or the radar may classify an aircraft as a ballistic trajectory. The false target rate improved from previous operational testing and met requirements for 90-degree Normal and 360-degree modes, but not for the 90-degree Short-Range Optimized Mode (SROM). When the radar reports a false target as a normal target, the operator is not able to distinguish the false target from an actual target generated by a threat. False. targets can lead to units wasting time and resources by reacting to false warning and firing at non-enemy locations; be disruptive to units if they cause the Sense and Warn system to generate false alarms in defended areas; and can lead units to perceive the Q53 radar as not reliable. The false targeting rate for aircraft remains a significant concern and warrants further investigation and corrective action.

Comments: Most of these false targets and/or false tracks are due to miss classification of targets; but others are due to radar internally generated ghost tracks. Namely ghost tracks can occur when the radar resolves range and/or Doppler ambiguities for example such as from a low or medium PRF waveform. When this Q53 radar scans over an air field on a FOB it can produce false tracks. Note: When the operator does not know the origin of the track he classifies it as a ghost.

Operation[edit]

1) PM C-RAM with the Phalanx: A 20mm LPWS (Land-Based Phalanx Weapon System), a land based variant of the US's Phalanx Close-in weapon system.

2) Iron Dome: an Israeli missile system featuring multiple-target tracking and self-guided missile interceptors. Due to the ongoing increase of its engagement range and new missile and interception improvements, plus Surface-to-air missile capability, it has developed into a fully-fledged air defence system. By November 2012, the system had intercepted over 400 rockets fired into Israel by Gaza Strip militants. Based on operational success, defense reporter Mark Thompson estimates that Iron Dome is currently the most-effective and most-tested counter missile system in existence. Note: PM C-RAM developed and successfully tested a system similar to Iron Dome. [1]

3) Nächstbereichschutzsystem MANTIS: 35mm fully automated C-RAM system, produced by Rheinmetall based on Oerlikon's Skyshield and ordered by the German Air Force in use from 2011.

4) Porcupine: A typical Porcupine configuration for the Italian Army consists of four firing units, one central control post for target designation and weapon control and a 3D radar system "track while scan type" for surveillance and target tracking. Each remote firing unit consists of a 20 mm M61A1 Gatling cannon, its ammunition handling system and a stabilised optronic infra-red (IR) tracking system.[2]

5) DRACO: The DRACO is a multipurpose weapon station operating against Air, R.A.M. and Surface targets, designed for the Italian Army. The main armament consists of a high rate of fire 76/62mm gun with an automatic ammunition loading system; the 76/62mm gun is electrically controlled for elevation and traversing, and is stabilized in elevation. DRACO can be installed on 8x8 wheeled platforms, for combat support operations or convoy defence, as well as on tracked vehicles or on shelters for point defence. The main 76/62mm gun and the automatic loading system are fully compatible with all in service 76mm rounds and also with 76mm DART guided ammunition. DRACO can be completely controlled by two Operators (the Commander and the Gunner) from a remote position, located inside the hull for mobile installation or inside a protected command shelter for fixed installation.[3]

Development[edit]

Raytheon is developing a laser-based variation where low cost focused lasers will provide increased range and decreased time-to-intercept over the gun. A proof of concept was demonstrated on a 60 mm mortar round in 2006.[4]

Iron Beam is an air defense system in development by Israeli defense contractor Rafael Advanced Defense Systems.[5] Unveiled at the 2014 Singapore Air Show on February 11[6] , the system is designed to destroy short-range rockets, artillery, and mortars with a range of up to 7 km (4.3 mi), too small for the Iron Dome system to intercept effectively.[5] In addition, the system could also intercept unmanned aerial vehicles.[7] Iron Beam will use a "directed high energy laser beam" to destroy hostile targets with ranges of up to 7 kilometres (4.3 mi).[5][8] Iron Beam will constitute the fifth element of Israel's integrated air defense system,[5] in addition to Arrow 2, Arrow 3, David's Sling, and Iron Dome.[9] However, Iron Beam is also a stand-alone system.[7]

Expanded Efforts: The US has been enhancing its Directed-Energy (DE) capabilities aimed at countering threats posed by missiles. A directed energy weapon is a ranged weapon system that inflicts damage at a target by the emission of highly focused energy, including laser, microwaves and particle beams. Potential applications include anti-personnel weapon systems, missile defense system, and the disabling of lightly armored vehicles or mounted optical devices.

The US Army has secured a $29m contract with Kratos Defense & Security Solutions to support its DE systems (2016). The company will commit to developing prototype technologies, components and subsystems to support the advancement and upgrade of the existing or new DE systems, according to army-technology.com.

This effort will help expand the DE system capabilities of counter rocket, artillery and mortar (C-RAM), counter unmanned aircraft systems (C-UAS), and/or counter intelligence, surveillance, reconnaissance (C-ISR) missions.

The prototype technologies to be developed include beam control, high energy lasers, adaptive optics, sensors, fire support and target tracking. They will be able to directly increase mission effectiveness of the US military personnel, in addition to the supporting platforms, systems, components or materials proposed to be procured or developed by the US Army. Work is expected to be carried out at several Kratos facilities and government locations in Huntsville, Alabama, US.

Operators[edit]

See also[edit]

References[edit]

  1. ^ Thompson, Mark. "Iron Dome: A Missile Shield That Works". Nation.time.com. Retrieved 21 January 2018.
  2. ^ a b "PORCUPINE C-RAM - DETAIL - Leonardo - Aerospace, Defence and Security". Otomelara.it. Retrieved 21 January 2018.
  3. ^ a b "DRACO - DETAIL - Leonardo - Aerospace, Defence and Security". Otomelara.it. Retrieved 21 January 2018.
  4. ^ "A Laser Phalanx?". Defenseindustrydaily.com. Retrieved 21 January 2018.
  5. ^ a b c d Williams, Dan (Jan 19, 2014). "Israel plans laser interceptor 'Iron Beam' for short-range rockets". JERUSALEM: Reuters. Retrieved 21 January 2014.
  6. ^ http://www.rafael.co.il/Marketing/195-1951-en/Marketing.aspx
  7. ^ a b RAFAEL Develops a New High Energy Laser Weapon | Defense Update:
  8. ^ Israeli company to unveil laser defense | UTSanDiego.com
  9. ^ Israel's Rafael to unveil laser-based defense system - Diplomacy and Defense Israel News | Haaretz
  10. ^ "Royal Artillery Careers". Ministry of Defence. Archived from the original on 31 March 2009. Other operational commitments are conducted (in the tertiary role) using C-RAM - a new and highly sensitive self defense system which destroys rockets and projectiles in flight. Applicable to Gunner Rapier applicants only.
  11. ^ "16th Air Land Regiment, RAA". Australian Army. Archived from the original on 29 March 2013. Retrieved 13 September 2012.
  12. ^ "Flugabwehrgruppe 61" [Air Defence Group 61] (in German). Luftwaffe (German Air Force). Retrieved 5 September 2017.

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