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*FM 34-40-7

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Preface

This manual explains how to employ the effective jamming techniques referencedin FM 34-1. Instructions are presented to the mission planner for calculating theminimum jammer power output requirements and the maximum distance ajammer can be placed from a target receiver based upon the jammer’s poweroutput. This information can be found by using the electronic warfare jammingcalculator (appendix). Doctrine, tactics, techniques, and procedures in this fieldmanual are intended for commanders and their staffs, division tactical operationcenters, technical control and analysis elements (TCAEs), mission managementpersonnel, and other personnel who plan or conduct jamming operations. Thispublication applies equally to active Army and Reserve Components.The proponent of this publication is Headquarters, United States Army Trainingand Doctrine Command. Send comments and recommendations on DA Form 2028directly to the Commander, United States Army Intelligence School, Fort Devens(USAISD), ATTN: ATSI-ETD-PD, Fort Devens, MA 01433-6301.Unless this publication states otherwise, masculine nouns and pronouns do notrefer exclusively to men.

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Introduction

CHAPTER 1

Regardless of the terminology, most scholars would agree that communications involve at leastfour basic elements: transmitter, message, medium, and receiver. Communications occurwhen the receiver understands the idea sent by the transmitter well enough to provide someform of feedback. This publication approaches those communications that must rely on theelectromagnetic spectrum as a medium to convey messages. It focuses on the disruption of thelistener’s ability to receive.

IMPORTANCE OF COMMUNICATIONSThe execution of the AirLand Battle Doctrinerequires the skillful use of resources, targetacquisition, and strike capability. To do this, atimely and responsive working relationship must

exist between the respective combat forces.Reliable communications are needed to achievethis goal. The lack of communications can affectthe outcome of any battle.

IMPACT OF JAMMING ON COMMUNICATIONSJamming is an electronic countermeasures (ECM)technique which supports intelligence andelectronic warfare (IEW) doctrine. IEW doctrinedirects that jamming be integrated into variousphases of combat operations. Jamming degradescommunications by reducing or denying theenemy's ability to pass key information at critical

times and can cause enemy operators to becomeirritated, confused, or misled during offensive,defensive, or retrograde operations. When appliedsuccessfully, jamming can contribute to thefailure of those actions which depend oncommunications using the electromagneticspectrum. For example, an enemy fire direction

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net must communicate in order to function. power output, or switch to a less reliable means ofProper jamming can force the net to change communications.frequencies, reestablish communications, increase

ELECTRONIC WARFARE SUPPORT MEASURES SUPPORTTO JAMMING

Electronic warfare support measures are theprimary source of information used to identifyand develop jamming targets. The primaryfunction of electronic warfare support measuresis to gather information on the enemy’s electronicsystems. Electronic warfare support measuresinformation can be passed directly to ouranalytical systems where it is correlated withdata collected from multiple sources and used todetermine the enemy's locations and intentions.From listening to the enemy’s transmissions, wegain significant information about his electronicsystems. Some of this information is used todirect our actions to reduce his combateffectiveness by interfering with his electronicsystems. Further, it assists us to identify enemytargets and position our equipment to bestdisrupt or deny the enemy’s use of his systems.The techniques employed to deny the enemy’s useof his electronic systems area part of ECM called

jamming. Jamming is the action taken to reduceor deny the enemy’s effective use of his electronicsystems.Indiscriminate jamming wastes resources, couldimpede friendly communications, or could attractartillery fire. Consequently, jamming operatorsneed to know exactly who, what frequency, andwhen to jam. To obtain this information, missionplanners require data supplied through electronicwarfare support measures. We listen to and locateenemy emitters to gain this information; not onlyto correlate it with other data for intelligenceproduction, but to identify data needed to denythe enemy the use of his electronic systems.Electronic warfare support measures alsoprovide technical data on the enemy's abilityto jam friendly electronic systems. Thisinformation enables us to conduct protectivemeasures to ensure our continued use of friendlyelectronic systems.

DECISION TO JAM

The commander’s decision to use jamming isinfluenced by several factors. The key factor istiming. Intercepting, direction finding (DF), andjamming cannot be conducted simultaneouslyagainst the same targeted communications link.The identifiable electronic signature created byjamming signals readily exposes friendly jammerlocations. The tactical commander should treatECM assets the same as artillery assets, becauseECM mission results on communications can beas devastating as artillery on personnel andequipment. ECM assets are deployed to supportcommitted units based on their mission priority,

the capabilities of available systems, andpotential enemy actions. In the planning phase,thoughts should reflect the relative scarcity ofECM assets, their limitations, and their transienteffects. The commander must balance thenegative aspects of jamming operations againstthe positive tactical advantages of disruptingenemy communications.

Jamming, when integrated into combatoperations, must support the commander’s battleplan. IEW doctrine dictates that commanderswill integrate jamming with fire support and

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maneuver forces to disrupt and confuse enemyforces during offensive, defensive, or retrogradeoperations.

The commander’s decision to employ jamming iscarried out by military intelligence (MI) units andshould be coordinated with the fire supportelement and integrated into the commander’s firesupport plan. These MI units detect, identify, andlocate enemy communications nets and intercepttheir traffic to provide the commander withintelligence. The commander uses thisintelligence to decide when and where to employjamming in his concept of the operation. The MIunits also direct ECM against enemycommunications, jamming those based on thecommander’s decision. This capability to locatethe enemy, to intercept the enemy’s messages,and to hamper the enemy’s operations at criticalperiods contributes directly and indirectly to theeffectiveness of the friendly commander’s conceptof the operation.

Enemy nets, which routinely pass information ofintelligence value, should be identified andmonitored. Other nets, such as those having ahigh tactical value to the enemy but little or nointelligence value to friendly forces, could beattacked with jammers or fire support dependingon the tactical situation. Enemy securecommunications may also be jammed with the

intention of drawing the enemy into clear voicecommunications, thus allowing interception andfurther identification. Enemy jammers should belocated, reported, and destroyed based on thedemands of the tactical operation. Guidance forjamming, destroying, or exploiting enemyelectronic emitters should be reviewed before eachtactical operation. Additionally the TABOO,RESTRICTED, and GUARDED frequency listsmust be reviewed prior to the execution of alljamming missions (see FM 34-40).

Jamming should interrupt or disrupt the enemy’scommunication at decisive moments in the battle,for example, when key information needs to bepassed or new instructions are required. Jammingmay be effective for only the short periods thatthe enemy needs to take evasive action or toexecute countermeasures. Jammers need to beused judiciously and moved often to avoid theirdestruction.

Jammers support other combat actions by—Disrupting key command and control nets,thus slowing or disorganizing the enemy incritical situations.Denying the enemy the ability to react tochanges on the battlefield.Reducing the effectiveness of enemy firesupport and air control nets.

EMPLOYMENT OF JAMMING

There are three steps in employing jamming. Thefirst step concerns information collection andtarget acquisition. The second step involvesplanning the jamming mission. The third step isthe execution of the jamming mission. Thissequence is also called the decide, detect, anddeliver method.

The field commander is confronted with an enemyelectronic array that comprises thousands ofemitters and hundreds of communication nets.

Collectively this emitter density is meaninglessunless the emitters are sorted by—

Function.Position in a net.Position on the battlefield.Ability to affect the combat plan.

Once the enemy emitter has been identified andlocated, this information flows to a coordinationcenter where an interface occurs between

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intelligence and operations. Based on thisinformation the commander provides theguidance on whether to jam, destroy, deceive, orintercept for intelligence. As often as possible,this decision must be a part of the initial planningand coordination. When the decision is tointercept for intelligence purposes, it must becontinually reevaluated to determine whether tocontinue collecting, to initiate jamming, or todestroy. The commander provides the guidance tothe TCAE or the staff to identify certain nets thathave a high tactical value to the enemy, butminimal or no intelligence value to friendly forces.

Enemy command nets of units in contact, firedirection nets, and enemy target acquisitionsystems usually meet this criterion. As these netsare identified and located, they are jammed ordestroyed in accordance with the commander’sattack guidance.Jamming must complement the concept ofoperation. Jamming provides the commanderwith time to reactor time to change his estimateto gain the tactical advantage. To maintain thistactical advantage, jamming would best be usedagainst priority targets and with careful timing toachieve the desired tactical results.

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CHAPTER 2

Integrating Jamming IntoCombat Operations

The objective of jamming is to disrupt the enemy’s effective use of his combat forces by reducingthe effectiveness of his communications. The function of jamming is to disrupt or deny theenemy the reception of his electromagnetic signals radiating from his radio transmitters. Jam-ming can be subtle and difficult to detect, or it can be overt and obvious when missionrequirements arise which override survivability. Jamming integration is explained in a step-by-step process (Table 2-1), which is based on the following war-game scenario:

The mechanized division’s commander directs the G3 to plan an operation to seize Hill 322.Intelligence reports indicate elements of the enemy's 231st Motorized Rifle Regimsnt are active inthis area. The G3, in coordination with the G2, tasks the collection management anddissemination section to determine the enemy unit's location. The operation plan requires thedivision to attack through the regimental area. The 2d Brigade will lead the main attack andthe 1st Brigade will conduct a supporting attack.

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The first three steps are always accomplished by close coordination between the G2 and G3.These actions are never formally labeled, except as a part of a mental war-gaming of a sequenceof actions and counteractions. These three steps are a form of tactical threat analysis, whichidentifies potential threats posed by enemy maneuver or weapon systems. Identified potentialthreats are then placed in priority order for jamming. The second three steps involve thetechnical considerations for jamming.

FOCUS ON THE TACTICAL OBJECTIVEIn step 1 (Figure 2-1), the G3 is acting for the Until this is done, jamming support cannot becommander. The G3 provides the same focus for integrated into the combat operation.integrating jamming as he would for integrating The initial guidance provided by the G3 makesany other division weapon system. In theelectronic warfare annex of the operation order,

planning and coordinating easier for the mission

the G3 directs that priority jamming support bemanagers. An artillery unit cannot furnishintegrated support until it receives the necessary

provided to the 2d Brigade. This, in effect, data on where and when to fire. Likewise,focuses the jamming support on a specific unit or jamming cannot support combat operationsoperation and establishes the guidelines for effectively until it is focused on the threatintegrating jamming into the combat operation. confronting our forces.

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This initial focusing step narrows the area of assessment of the target and friendly force’s useconcentration. It also identifies any conflicts of the electromagnetic spectum. If jamming isamong jamming, intelligence collection, integrated into the operation, the signal officerand friendly use of the electromagnetic spectrum. may have to realign the signal operationThis conflict resolution involves the G2, G3, instructions.signal officer, and MI assets to perform the overall

PLACE ENEMY UNITS IN PRIORITY ORDERIn step 2 (Figure 2-2), the G2 and G3 consider based on their potential threat to the mission.the enemy units that could prevent the (In combat, priorities are normally situationaccomplishment of the division’s mission. These dependent.)units are placed in a priority order for jamming,

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PLACE IDENTIFIED SYSTEMS AND FUNCTIONS INPRIORITY ORDER

In step 3 (Figure 2-3), the G2 and G3 identify the to the tactical operation. Listed near each unitvarious weapons systems and threat functions (also in priority order, as shown in Figure 2-2) areavailable to the units listed in step 2. These weapon systems and threat functions whichweapons systems and threat functions are then impose the greatest threat to the attack. Theplaced in priority order on the basis of the greatest threat imposed by the priority one unit isgreatest danger to the attacking friendly force. the enemy's reconnaissance elements. This isThe second and third steps are constrained to fit expected since reconnaissance elements tip-offinto the specific guidelines as directed by the G3 other forces and weapon systems. If we(in step 1). The further the mission progresses on successfully jam the reception of their reports, wethe battlefield, the more specific the direction can delay their reporting of the 2d Brigade’s pointbecomes. of attack. The jamming will, in turn, delay the

Enemy ReconnaissanceIn step 2, we circled enemy units in priority order(1 through 4) on the basis of their potential threat

enemy’s reaction time against our attacking force.

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Enemy Antitank Guided MissileControl NetsThe next threat under the priority one unit is theenemy's antitank guided missile control nets. Theenemy will eventually detect our attacking forceand will begin to target our key elements. Keyelements include personnel, weapons systems,tanks, and armored personnel carriers. Jammingthe communications controlling the antitankguided missiles reduces the effective coordinationand movement of their weapons systems.

Artillery ThreatThe artillery threat is listed in the third priority.Therefore, we jam their fire request and firedirection net between the command andobservation post (COP) and the firing battalions.The division commander may also want theartillery threat destroyed. In that case, the

used to locate these targets for our own artilleryor close air support.

ManeuverManeuver is listed fourth since this particularenemy unit appears to be in a defensive position.

Enemy Electronic Warfare ThreatThe enemy electronic warfare threat, especiallyjammers, is listed next. We can get to this pointof attack without an overdependence on ourradios. Since we have just started the attack, allof the unexpected events which complicatepreplanned coordination have not begun. As wecontinue to attack, our radios become increasinglyimportant. To ensure our continued use of theseradios, we must use our DF assets to locateenemy jammers. Once located, these jammersmust be destroyed by friendly artillery or close air

electronic warfare support measures assets can be support (Figure 2-4).

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Close Air Support ThreatThe close air support threat is listed next to lastbecause the enemy normally will not react untilour point of attack has been established. As theattack continues, the close air support threatbecomes more important and must be given ahigher priority.

Air Defense Artillery ThreatThe air defense artillery threat is listed last onlybecause our attack may not require air assets. Itis listed to alert the electronic warfare supportmeasures assets concerned with locating enemyradars in the combat zone. If our attack stalls, wecan use close air support to regain themomentum. Close air support can attack enemyradars located by electronic warfare supportmeasures, while our jammers attack theircommunications.The priority two unit has only four threatsidentified. This is done, primarily, to show themas possible targets of opportunity since that unit

should be preoccupied with the 1st Brigade’ssupporting attack. The threats imposed by thisenemy unit are also placed in priority order sincethe enemy unit could target our armor ormaneuver against the flank of the 2d Brigade’sattack.

Priority three is outside the zone of influence, butas we advance, so will our zone of influence. Thisenemy unit could maneuver against us, attempt alimited counterattack, or direct artillery againstour advance. The electronic warfare and airdefense artillery threats gain more importance asour advance progresses.

These first three steps are always accomplishedby close coordination with the G2 and G3. Aspreviously stated, we have never really labeledthese actions other than as a part of the mentalwar-gaming of a sequence of actions andcounteractions. These three steps identify thepotential threat from enemy maneuver or weaponsystems. Identified potential threats are thenprioritized, jammed, or attacked by fire.

IDENTIFY ENEMY ELECTRONICS USED TO CONTROLWEAPONS SYSTEMS AND THREAT FUNCTIONS

The initial jamming mission planning begins withstep 4. It is the transition point between tacticaland technical jamming considerations. We mustnow identify those enemy electronics used tocontrol the weapons systems and threat functionsof greatest concern. We can do that by answeringtwo questions. What communications systems areassociated with each threat function? And, whattechnical and operational characteristics areknown about these systems? We already knowabout the enemy’s electronic systems in general.We know some systems can use the same radios.We know jamming can be more effective againstsome threats than against others. We also knowthat jamming alone will not totally defeat theenemy. At this point, we progress with the

planning phase just as we would for constructinga schedule of fires, except that we are puttingjamming on the target, not artillery fire.

The electronic warfare section (EWS) searches itselectronic order of battle files. The search is forenemy communications systems serving eachweapon system and threat function. The EWSconcludes that the 231st Motorized RifleRegiment’s reconnaissance element uses a veryhigh frequency (VHF) frequency modulated (FM)radio. This radio has a maximum power output of20 watts. The EWS also determines that the netcontrol station will receive the initial reports ofour point of attack. The net control station islocated about 8 kilometers (km) to the rear of the

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231st Reconnaissance Battalion. The EWS also radio to report information. The EWS continuesknows that the enemy target acquisition batteries through the enemy electronic order of battleare deployed in our zone of attack. These inventory, identifying any additional data usefulbatteries use battlefield surveillance radars to to the TCAE or other operational elements. Stepsdetect moving targets. The EWS further resolves 1, 2, and 3 must be completed before step 4that a target acquisition battery uses VHF FM (Figure 2-5).

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PROVIDE TECHNICAL DATAIn step 5 (Figure 2-6), technical data is providedto the TCAE. This requires detailed coordinationwith the EWS. The TCAE provides jammingmission planning to the MI battalion’s S3 basedon the initial planning by the G2 and G3 as wellas input from the EWS. The TCAE lists thetargets from the electronic warfare annex inpriority order and then enters technical andoperational characteristics for each target. Thefollowing information on each enemy target isentered:

Unit.Frequency.

Call signs.Power.Antenna type.Antenna height.Link distance.Enemy transmitter location.Enemy transmitter location elevation.Target receiver location.Target receiver location elevation.

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COMPUTE JAMMING DATA AND TASK ASSETSIn step 6 (Figure 2-7), the TCAE uses the personnel (Figure 2-8, page 2-10). The TCAE’stechnical data listed in step 5 to compute the efforts conform to the requirements initiallyminimum jammer power output required for provided by the G3.jamming to be effective. This means that thejammer must be capable of producing at least this In steps 5 and 6, we have entered some of theamount of power output for the jamming mission data available from the enemy electronic order ofto be effective. The same data can also be used to battle. For example, in step 5, we indicated thatcompute the maximum distance the jammer the radio station associated with the first prioritylocation can be located from the target receiver target (the 231st Reconnaissance Battalion)location based on the jammer’s maximum power transmits on 44.25 megahertz. The alternateoutput. This same information, plus target frequency is unknown. This radio station uses thepriorities and jamming on-off times, are a part of call sign AK17. Its transmitter radiates 20 wattsthe multiple asset tasking message sent to the of power with a 25 kilohertz bandwidth from ajamming assets. vertically polarized whip antenna. The whip

antenna is omnidirectional. The TCAE hasThe jamming computations are further refined by calculated that 100 watts of power are needed tosuccessive planning and directing by the TCAE jam the target receiver from coordinates

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EZ341795 (Hill 345). This calculation was madeusing the Electronic Warfare JammingCalculator, GTA 30-6-5 (see appendix). Thevarious zones are calculated based on differentjammer outputs using the GTA 30-6-5.In step 6, we calculated that the jammer wouldhave to be on Hill 345 in Zone B to be effective.Figure 2-9 shows that the battlefield has beencross-referenced and assigned zones for locatingthe jamming teams.

Assigning zones also provides greater flexibility tothe jamming teams and permits them to adapt tolocal conditions and restrictions. In the remarksblock of Figure 2-7, we identified the ON-OFFcontrol frequency. This frequency must bemonitored by the jamming teams to facilitate

positive control so jammers can be turned on andoff for careful synchronization with otherbattlefield systems (for example, artillerypreparatory fire, a diversion, or a deceptionoperation) or if unexpected problems arise (forexample, jamming a frequency used by a medicalevacuation helicopter).

We have discussed the sequence of actionsrequired by several different echelons whenintegrating jamming into combat operations.It is important to understand the relationshipsthat take place among the tacticians(as the managers), technicians, and operatingelements. The G3 or S3 implements thecommander’s guidance by integrating jammingwith the rest of the battle plan.

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CHAPTER 3

Planning the JammingOperation

An artillery commander’s fire control element performs many geometric calculations prior toexecuting a fire mission. These calculations are necessary to bring steel effectively on the target.The jamming mission planner must also perform geometric calculations to bring fire effectivelyon the target receiver through electromagnetic energy (electromagnetic steel).

IMPORTANCE OF JAMMINGThe jamming mission planner determines theminimum jammer power output required to jamthe target receiver effectively. When an excessamount of jamming power is radiated into the air,it is easier for the enemy’s DF equipment tointercept and locate the friendly jammer. For thejamming team to accomplish its mission, themission plainer must determine the distancebetween the jamming team’s location and thetarget receiver’s location. A proposed jammingmission must be carefully evaluated to determinethe proper deployment of the jamming team.Distances between the enemy transmitterlocation and the target receiver location, and

PLANNEDPlanned jamming requires the greatest amount ofdetail; for example, identifying the unit, thelocation, and the time window for the mission. It

between the friendly jammer location and thetarget receiver location, are two of the criticalconsiderations for jamming team placement.Each jamming team deployment is different.Therefore, constant evaluation of proposedjamming targets is necessary. Terrain isimportant because line of sight (LOS) isnecessary between the jammer’s location and thetarget receiver’s location. The enemy can beexpected to use terrain to gain an advantage. Thetype of jammer to be employed is anotherconsideration because some jamming systemshave a different power output than others.

JAMMINGmust be totally synchronized with fire supportand maneuver to achieve maximum results.Planned jamming missions can engage a target

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simultaneously with fire, or singularly engagelower priority targets simultaneously with fire onhigher priority targets. The electronic warfaretasking list (EWTL) can and should list specifictargets and times to guide jamming so all targets,regardless of the jamming method used, can bespecified in the EWTL. Planned jammingmissions could be integrated with fire missionsusing a field artillery target list work sheet and ascheduling work sheet (Figures 3-1 and 3-2). Aplanned mission can be used in a direct offensive,a supporting offensive, or a deceptive role. In thedirect offensive role, the mission would betargeted against the unit being attacked.A supporting offensive role would consist ofjamming those enemy units capable of reinforcingtheir point of attack. A deceptive jamming

mission can consist of jamming against oneenemy unit prior to attacking a different enemyunit. The type of role or mission chosen dependson the tactical situation, the degree of knowledgeof the enemy situation, the availability of assets,and the objective of the tactical mission. Plannedmissions can be further divided into scheduledand on-call missions.

Scheduled MissionThe scheduled mission, on a completedscheduling work sheet, depicts the enemy’s unit,target location, and time that jamming is to beconducted. The time of the jamming mission issynchronized with the time of the fire mission toprovide the greatest degree of support to themaneuver unit.

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On-Call Jamming On-call jamming missions should be

On-call jamming is dependent upon the unit andincorporated as necessary into the master fire

location; however, time cannot be ascertainedsupport (targeting) plan and the fire support

because it is situationally dependent. Therefore,execution matrix. Communications interfacesmust be adequate to be able to execute the on-call

on-call jamming missions lend themselves totargeting reinforcing or second echelon units.

mission at the appropriate time.

ELECTRONIC MASKINGElectronic masking, often called screen jamming,is also a planned mission. The purpose ofelectronic masking is to protect or mask friendlycommunications by denying the enemy the abilityto intercept and locate them. Electronic maskingis used when mission requirements necessitatethe immediate transmission of criticalinformation, and there is no other way to conveythe information. Just as offensive jamming

using directional antennas close to the forwardline of own troops (FLOT). Electronic maskingcan best be used to mask the radio signals offriendly reinforcements being moved on line, thuspreventing enemy signals intelligence fromdetermining the disposition of the reinforcingunit. Figure 3-3 depicts an electronic maskingoperation. The enemy’s ability to locate a jammeraccurately through direction finding is reduced by

captures the receiver of the enemy, electronic using two or more jammers for an electronicmasking captures enemy intercept and DF masking operation.systems by jamming on the friendly frequency

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SOP JAMMINGStanding operating procedures (SOP) jammingmeans allowing the jamming operator to jamtargets upon recognition. The SOP jammingtechnique is used when it is impossible tocompute the jamming-to-signal ratio for effectivejamming. The SOP jamming technique requiresthat the jammer’s maximum power output mustbe used to ensure mission effectiveness; therefore,the jammer’s power output cannot be reducedduring SOP jamming. In certain situations, eventhe least amount of power reduction could renderthe jamming ineffective. Our jamming operationsmust be able to ensure success when the decisionto jam is made. SOP jamming has the followingdisadvantages, which should be considered priorto its implementation:

It does not allow for step-by-step coordinationwith frequency managers, intelligencecollectors, or friendly forces in the jammingmission area of operations.The operator will not know if the jammingequipment location is close enough for thejamming signal to overcome the enemytransmitter signal at the target (enemy)receiver’s location, without prior planning.Uncontrolled, high-powered jammers can havea disastrous effect on unwarned andunprepared friendly communications.

Maximum jammer power output meansmaximum electronic visibility andvulnerability to the enemy electronic warfareforces, which could result in the destruction ofthe friendly jamming asset.

The two methods for employing the SOP jammingtechnique are called jam upon recognition andtargets of opportunity.In the jam upon recognition method, the operatoris tasked to search for enemy targets. As soon asthe target is identified, it is jammed. Theoperator is not tasked to jam specific targets atspecific times. Under emergency conditions thereis no time to plan and coordinate the jammingeffort.The targets of opportunity method is used againstspecific enemy units placed in priority. Thismethod occurs after the targeting process iscompleted. The G3 or S3 organizes specific enemytargets in a priority order based on the inputfrom the EWS and the fire support coordinator.The TCAE’s ECM planning section determineswhen to jam each target based onthe distinguishing traits of the target’scommunications. Each communications jammingteam receives the SOP target jamming list. Thelist contains target call signs, type of traffic, andfrequencies. The communications jamming teamsare authorized to jam each target according to theinstructions on the SOP target jamming list.The SOP jamming schedule is neither time norlocation oriented. Jamming can be performed asjam upon recognition based on taskingrequirements and target activity or targets ofopportunity, which requires no tasking and isbased solely on target activity. Remember, thejammer’s maximum power output is used, andcommanders must be made aware of thedisadvantages of SOP jamming.

SURGICAL VERSUS SIGNAL INITIATED JAMMINGPlanned, on-call, and SOP jamming are the forms signal which makes it difficult for the enemyof jamming referred to as surgical jamming. operator to know if he is being jammed. SignalThe surgical jamming technique interrupts the initiated jamming (SIJ) is the jamming oftarget signal using a continuous wave jamming frequencies programmed into the jammer and

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they are automatically jammed as they become or listen. SIJ is effective only when the operatoractive. As a result, a communications check could can verify that the transmission should bebe jammed and tip off the jamming effort. SIJ jammed. Surgical jamming is the most effectiveincreases the chance of fratricide, since the and is desired over SIJ. Also, the jammer’sprogrammed frequency would be jammed maximum power output is very important to theregardless of whether it is friendly or enemy. In success of surgical jamming, when theaddition, SIJ bypasses the decision process to jam jamming-to-signal ratio cannot be computed.

HIGH POWERED COMMUNICATIONSHigh powered communications consist of using when communications are mandatory, highthe jammer as the communications equipment to powered communications will overcome eitherincrease the power output for friendly natural (static) or intentional (enemy ECM)communications. At critical points of the battle, interference.

FUNCTIONS OF MISSION PLANNINGPlanning the jamming mission in response tospecific tactical operations consists of manyfunctions. These functions include—-

Target isolation.Resource selection.Mission analysis.Effective jamming.Terrain analysis.

Target IsolationUpon receipt of a jamming mission requirement,the jamming mission planner obtains target databy searching the enemy electronic order of battle,electronic warfare support measures, and otherfiles. As information on the potential target ischecked, frequency parameters are reviewed todetermine if they conflict with restrictedfrequencies. Conflicts are identified and reportedto the command establishing the restriction, whois responsible for resolving the conflicts.Unresolved restrictions are noted and added tothe target files as restricted frequencies untilthey are resolved.

Resource SelectionThe next step is to compare the jamming missionwith available resources. Information on the type,number, location, and status of friendly jammersis required to effectively assign the mission. Themultiple asset status report provides the status ofthe major assets to the asset manager. Jammingmission requirements that cannot be satisfied byorganic direct support capabilities requiresupport from a higher echelon.

Mission AnalysisThe mission planner conducts a detailed analysisof the actual target network based on hisgeometric calculations, which indicates that themission has a high probability of success.Analysis isolates the expected pattern of activityand structure for the various jamming operationphases being planned and establishes theengagement methods and timing for maximumtarget degradation. The multiple asseteffectiveness report provides missioneffectiveness data from the jammer to the assetmission manager.

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The type and number of jamming resourcesrequired are examined to ensure that thoseselected are capable of accomplishing the plannedmission. If required, any additional jammingresources needed are identified and requestedfrom the supporting MI unit, Coordination,logistics, and communication problems areidentified and procedures for their resolution areestablished. The multiple asset tasking messageis then prepared and passed to the appropriatejamming team.

Effective JammingIf the jamming-to-signal ratio for FMsignals is large enough (or larger), jammingwill be effective. If the jamming-to-signalratio is too small, then jamming will not beeffective (see jamming formulas in the

appendix). Effective jamming disrupts, delays, orprevents the effective use of communications bythe enemy. The jammer should, ideally, radiateonly the amount of power output necessary(minimum jammer power output required) tointerfere with the reception of the enemytransmitter signal in the target receiver.Jamming is most effective when it interferes withthe enemy’s communications without disclosingits presence. The jammer’s power output mustelectronically capture the target receiver(Figure 3-4). Capture occurs when the strengthof the friendly jammer’s signal is stronger thanthe enemy transmitter’s signal in the targetreceiver. In this situation, the frequencymodulated receiver will be captured by thefriendly jamming signal causing the targetreceiver to reject the weaker enemytransmitter signal.

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Terrain Analysis where they can take advantage of any terrain

An analysis of the terrain features between the features that could reduce or block the jammingfrequency from interfering with friendlyjammers’ location and friendly units is necessary communications.to prevent inadvertent jamming of friendly

communications. Jamming sites should be located

UNDERSTANDING JAMMINGTo understand jamming, consider the followingsituation:

The operation plan identifies the enemy's COP and the associated communications aspriority targets for jamming. The COP has located our battalion task force (BTF) and is passingthis information to the advance guard battalion (AGB) (Figure 3-5). There is no inteeferencewith their communications. The AGB operator is able to hear and copy all of the COP’stransmissions.

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Identifying the Target Tasking the Mission

Intercept positions have identified the COP and This information is forwarded, using secureAGB frequency and intercepted the link’s communications, to the appropriate jammingtransmissions. DF operations provided a general team. Upon receiving the tasking, the jamminglocation for both stations. The emitter locations equipment is deployed to the designated location.are given to the TCAE, where the jamming The jamming equipment operator then—mission is planned. The mission plannerdetermines the minimum jammer power output Tunes the jammer to proper frequency.required to jam the COP and AGB Makes the necessary adjustments based oncommunications as well as a location to deploy the multiple asset tasking message.the friendly jammer (Figure 3-6). Jams the target receiver as directed.

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Accomplishing the MissionThis mission successfully disrupted the enemycommunication and delayed passage of theinformation. Therefore, the mission plannercomputed the correct minimum jammer poweroutput required for this mission and the enemy’starget receiver was captured. Jamminginterfered with receipt of the message andrequired the AGB operator to ask for repeats of

electronically capture a target receiver. Thecriteria for determining the minimum jammerpower output required to capture a receiver is notuniversally accepted. Before determining theminimum amount of jammer power outputrequired for a given tactical situation, the missionplanner must understand that groundbasedjamming is very complex. In free space, some ofthese variables are not important. However, onthe ground they can become critical. Some of the

the message. —variables which can cause attenuation of radio

Determining the Power OutputIt is very difficult, if not impossible, to determinethe exact jammer power output required to

waves are terrain, ground conductivity,vegetation, and weather (Figure 3-7).

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CHAPTER 4

Training

Two categories of training are required to prepare the soldier to operate a jammer in combat:resident and in-unit training. Voice interceptors (military occupational specialty 98G) must beskilled in communications intercept to recognize the target signal. While training in most MIdisciplines results in the awarding of a military occupational specialty, soldiers qualified in theskill of jamming receive an additional skill identifier of K3.

RESIDENT TRAININGResident training is currently taught during the training exercise is conducted at the end of eachCommunications Electronic Warfare Operations course. During the field training exercise theCourse (CEWOC). This training consists of student is evaluated for knowledge of—installing and operating ECM, electronic warfare Electronic warfare skills.support measures, and communications Perimeter defense.equipment. Training is conducted in ECM and Nuclear, biological, and chemical operations.electronic warfare support measures missionsagainst those targets unique to the student’s Survival skills.tactical duty assignment. A simulated field

IN-UNIT TRAININGIn-unit training refines skills learned during and survive. Survival is critical to the continuedresident training. It combines technical skills success of a unit. Therefore, in-unit training mustwith survival skills. This combination ensures emphasize the survival principles. It must stressthat the unit can conduct jamming operations the importance of reducing the amount of power

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and time a jammer’s transmitter is keyed andthat you transmit only with the amount of powerneeded to accomplish the mission. Using only theamount of power necessary to effectively jam andkeying the jammer’s transmitter in short burstsreduces the probability of detection by enemyintercept and DF equipment. In-unit trainingshould provide a means of measuring andcontrolling these two jamming principles. This ispossible when in-unit training is designed toallow soldiers to practice their jamming skills.

Unit trainers are challenged to make jammingtraining as realistic as possible. Realism isachieved when the jamming mission planner andthe jamming equipment operator are trained in asimulated combat situation. This setting allowsthe effectiveness of the mission planner to bemeasured. The successful execution of thejamming mission indicates that the missionplanner is effective. Successful mission planningand execution during in-unit training provide thetechnical and tactical skills needed in combat.

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APPENDIX

Jamming Calculations

The three methods used in jamming calculations involve jamming formulas, the GTA 30-6-5, andthe JAMPOT fan. The jamming formulas are used to determine the jamming power output andjammer distance to target. Calculations are made manually. The GTA 30-6-5 results require the aidof the electronic warfare jamming calculator. Likewise, the results achieved with the JAMPOT fanrequire the aid of a JAMPOT fan template.

ABBREVIATIONS AND FORMUL4SUnderstanding the abbreviations and jamming factors that impact on effective jammingformulas presented makes jamming mission missions. Once these factors are determined,computation easier. When planning a jamming they are used to select the proper jammingmission, it is necessary to make a thorough and equipment to conduct the jamming mission.reasonable appraisal of the significant technical

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Abbreviations they mean. Additionally, as you use theseStudy the following abbreviations before reading formulas, ensure you are using the numbers infurther. They will be used often, and a little time the proper units (for example, power in watts,spent on them now may preclude the necessity of distance in kilometers, and elevation in feet).constantly turning the pages to understand what

P j =

P t =

H j=

Minimum amount of jammer power output required in watts (read on power output meterof the jammer).

Power output of the enemy transmitter in watts.

Elevation of the jammer location above the sea level.

NOTE: The elevation of the jammer location and the enemy transmitter location does not include theheight of the antenna above the ground or the length of the antenna. It is the location elevationabove the sea level.

H t=

D j =

D t=

K =

n =

Elevation of the enemy transmitter location above the sea level.

Jammer location-to-target receiver location distance in kilometers.

Enemy transmitter location-to-target receiver location distance in kilometers.

Number 2 for jamming frequency modulated receivers (jammer tuning accuracy).

Terrain and ground conductivity factor.

5 =

4 =

3 =

2 =

Very rough terrain (rocky mountains or desert) with poor ground conductivity.

Moderately rough terrain (rolling to high hills, forested farmland) with fair to goodground conductivity.

Rolling hills (farmland type terrain) with good ground conductivity.

Level terrain (over water, sea, lakes, and ponds) with good ground conductivity.

Jamming FormulasJamming formulas provide the tools needed tocompute the jamming power output and jammerdistances. The formulas presented here arebased on a tactical situation where the enemytransmitter-receiver link and jammer-enemyreceiver link are operating over moderatelyrough terrain with no high hills between the twolocations. The enemy transmitter and friendlyjammer locations are at approximately the sameelevation above the sea level (difference is less

than 10 meters). When the terrain features differby more than 10 meters between the enemytransmitter and friendly jammer locations, themission planner must factor this difference intohis calculations.

FORMULA 1

Formula 1 (Figure A-1) is used to compute theminimum jammer power output that is required(the least amount) to effectively jam the targetreceiver.

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EQUIPMENT PARAMETERS data and can be obtained from the G2. WhenThe equipment parameters of friendly and enemy information is not available on enemyequipment are needed to solve this formula. The communications systems, it may becomeparameters of friendly equipment can be obtained necessary to estimate the parameters to reach afrom the technical manuals written for the solution. In the following tactical situation, theequipment. Technical intelligence publications on essential parameters needed to compute formulaenemy communications systems provide similar 1 are given as:

f =

Dt=

Dj =

Pt =

Pj =

H t=

Hj =

K =

n =

Frequency (37.5 megahertz).

Enemy transmitter location-to-target receiver location distance in km (9 km).

Jammer location-to-target receiver location distance in km (17 km).

Power output of the enemy transmitter in watts (5 watts).

Minimum amount of jammer power output required in watts (solve).

Elevation of the enemy transmitter location above the sea level in meters (385 meters).

Elevation of the jammer location above the sea level in meters (388 meters).

FM jammer tuning accuracy (2).

Terrain and ground conductivity factor (4).

Substitute the parameters in formula 1 using thesteps shown in Table A-1 on page A-4 to solvefor Pj.

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The selected jammer must be able to produce and represents the minimum power output readinguse 125 watts of power output to overcome the for effective jamming using a whip antenna inenemy's transmitter signal at the target receiver this tactical situation. The 62.5 watts is thelocation. Less than 124.6 watts of power will not minimum power for the same problem whenbe effective. If more than 125 watts are used, using the jammer’s log periodic array (LPA)jamming will still be effective. The 125 watts antenna.

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FORMULA 2

Formula 2 (Figure A-2) is used to compute themaximum distance that a jammer’s location canbe from the target receiver location and still beeffective. Use 1,500 watts as the maximumjammer power output in this tactical situation.Substitute the rest of the numerical values fromformula 1 for the parameters in formula 2. Usethe steps in Table A-2 to find the solution for themaximum jammer location-to-target receiverlocation distance.

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A-7

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A-8

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TERRAIN AND GROUND receiver location distance in kilometers. TheCONDUCTIVITY FACTORS internal numbers (1 through 26.4K) are

expressed in watts or kilowatts (K equalsAs previously mentioned, the attenuation of radio

.multiplication by 1,000).

waves is subject to terrain and groundconductivity factors (n). Table A-3 on page A-11is used to compute the minimum jammer poweroutput and maximum jammer location-to-targetreceiver location distance. Multiply the wattsfrom Table A-3 by the power output of theenemy’s transmitter to obtain the minimumpower output. The factor of n equals 5 is used forvery rough terrain (deserts or mountains) withpoor ground conductivity. The table is a matrix.The left column (reading down from 0.5 to 10.0) isthe jammer location-to-target receiver locationdistance in kilometers. The top line of numbers(0.5 to 5.0) is the enemy transmitter-to-target

To use the table, take the kilometers reading fromthe left column and the kilometers reading fromthe top line and find where they intersect. Forexample, if the jammer is 1.5 kilometers from thetarget and the enemy transmitter is 0.5 from thetarget, the factor is 486 watts. This means if theenemy transmitter uses only 1 watt, the jammermust use at least 486 watts to be successfulunder these conditions.The factor of 486 is achieved by dividing thejammer location-to-target receiver distance (1.5)by the enemy transmitter location-to-targetreceiver distance (0.5). The result (3) is first

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raised to the fifth power (243) and then doubled digits to the right of the decimal are used, and(486). When fractions are encountered as result the fraction is not rounded off. Therefore, for theof division (for example 8.5 km divided by 4.5 purpose of finding then factor, 1.8888 is viewedkilometers equals 1.8888), only the first two as 1.88.

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Table A-4 is similar to Table A-3, but the internal receiver distance by the enemy transmitternumbers are changed. They are based a factor location-to-target receiver distance, the result isof n = 4. After dividing the jammer-t.o-target raised to the fourth power and then doubled.

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Table A-5 is based on a factor of n = 3. After receiver distance, the result is raised to the thirddividing the jammer-to-target receiver distance power and doubled.by the enemy transmitter location-to-target

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Table A-6 is based on a factor of n = 2. Afterdividing the jammer-to-target receiver distanceby the enemy transmitter location-to-target

receiver distance, the result is raised to thesecond power and doubled.

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Tables A-3 through A-6 are reliable under thefollowing conditions:

Elevation of the jammer location above the sealevel is approximately the same as theelevation of the enemy transmitter location(less than 10 meters difference).Power values obtained from the tables matchthe reading on the jammer’s power outputmeter. (Antenna loss and voltage standingwave ratio have been taken into account.)Power values are used with the jammer’s whipantenna.Jammer location must have a reasonable LOSpropagation path to the target receiverlocation with no high hills between the twolocations.Jammer is used against frequency modulatedvoice communications in the VHF range.

The exceptions to the above conditions are—If the elevation of the jammer location and theenemy transmitter location difference is 10meters or more.If the LPA antenna is used instead of a whipantenna, the power indicated must be dividedby 2.

ELEVATION RATIO ANDMULTIPLICATION FACTORS

Table A-7, page A-16, is used to convert theminimum jammer power output value obtainedfrom Table A-3. It is used when the elevationdifference of the jammer location and the enemytransmitter location is 10 or more meters.

Determine the Elevation RatioTo convert the minimum jammer power outputfrom Table A-3, the elevation ratio must be

determined. To do this, divide the jammerlocation elevation by the enemy transmitterlocation elevation. The jammer location-to-enemytransmitter location elevation ratios are listed inthe left column in Table A-7. Rounding down, findthe next lower elevation ratio number which isclosest to your computed ratio. Always round theratio down to the next lower ratio number in thetable to ensure that there will be sufficient poweroutput for effective jamming. The figure to theright of the numbers is the elevationmultiplication factor. Multiply the minimumjammer power output value from Table A-3 by theelevation multiplication factor from Table A-7.The result is the final minimum jammer poweroutput necessary for effective jamming, in thislocation elevation ratio situation.

Determine the Multiplication Factor

As an example, we will use the minimum jammerpower output from Table A-3 of 64 watts. Theelevation of the jammer location is 435 metersand the elevation of the enemy transmitterlocation is 557 meters. Determine the locationelevation ratio by dividing the jammer locationelevation (435 meters) by the enemy transmitterlocation elevation (557 meters). The result is thefraction .78. Round the fraction down to thenearest number on Table A-7 (.75). Read to theright of .75 and the multiplication factor is 1.8.Next, multiply the jammer power output selectedfrom Table A-3 (64 watts) by the multiplicationfactor of (1.8). The answer is 115.2 or 116. The116 watts is adjusted into a power output figureused in computing the final jammer power outputwhich can be used for effective jamming.

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MINIMUM JAMMER POWER OUTPUT REQUIREMENT

Table A-8 is a step-by-step exercise to determinethe minimum jammer power output for effectivejamming using Table A-3 (desert terrain) withthe following parameters:

Enemy transmitter-to-target receiver distance

Jammer-to-target receiver distance (18 km).Enemy transmitter power output (1.5 watts).Jammer location elevation above the sea level(85 meters).Enemy transmitter location elevation abovethe sea level (68 meters).

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MAXIMUM JAMMER DISTANCEThe following parameters are provided tocompute the maximum distance a jammerlocation can be from the target receiver location(Table A-10):

Enemy transmitter-to-target receiver distance

Enemy transmitter power output (2 watts).Jammer power output (550 watts).Jammer location elevation above the sea level(385 meters).Enemy transmitter location elevation abovethe sea level (386 meters).

(3 km).

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THE GTA 30-6-5 CALCULATORThe Electronic Warfare (EW) Jamming power output required for effective jamming.Calculator (Figure A-3), provides a quick and This calculator can be used with any size map.easy method to calculate the minimum jammer

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GTA 30-6-5 Calculator EffectivenessThe GTA 30-6-5 calculator is effective under thefollowing conditions and parameters when—

Frequency modulated voice communications inthe VHF range are used.

The enemy communication transmitter poweroutput is known.

The enemy communicationtransmitter-to-target receiver distance inkilometers is known.

The jammer location-to-target receiverlocation distance in kilometers is known.

The jammer location, enemy transmitterlocation, and target receiver location areknown.All location elevations are measured from thesea level.

Power output values calculated using theGTA 30-6-5 calculations are for the jammer’swhip antenna. (If the LPA antenna is used,divide the final calculated power output by 2.)The minimum jammer power outputcalculated (in watts) must be read on thejammer’s power output meter.Jammer location must have a reasonable LOSpropagation path to the target receiver’slocation with no high hills between the twolocations.

Minimum Jammer Power OutputRequired for Effective Jamming

Use the GTA 30-6-5 calculator shown inFigure A-3 to determine the minimum jammerpower output required for effective jamming.Calculations include the minimum power for thewhip antenna and the LPA antenna (Table A-11).

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A-23

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A-24

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A-25

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The jammer must be capable of producing at least jammer site can be from the target receiver and114 watts with the whip antenna or 57 watts for still jam effectively. Use the GTA 30-6-5the LPA antenna for jamming to be effective. If a calculator to find the maximum power output ofhigher power value is used, the jammer will still the jammer.be effective. Using any power output less thanthese values will not effectively jam the targetreceiver for this example.

Compute the Maximum Distance theJammer Can Be From the TargetReceiverPerform the following steps in Table A-12 tocalculate the maximum distance the selected

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A-27

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A-28

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A-29

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GTA 30-6-5 Calculator Work Sheet power output required for a given jamming

The GTA 30-6-5 calculator work sheetsituation. Table A-13, page 32, explains how to fill

(Figure A-4) is to be used with the GTA 30-6-5in the work sheet.

calculator when computing the minimum jammer

A-30

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A-31

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A-32

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Figure A-5 shows a completed GTA 30-6-5calculator work sheet. The elevation differencereflects data from step 2B.

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THE JAMPOT FAN

The JAMPOT fan (Figure A-6) provides another developed for a map scale of 1:50,000. It can alsomethod for measuring distances needed to be used for a map scale of 1:100,000 bycalculate the required jamming power output. It multiplying the jammer-to-target receiveris designed to be used with Table A-14, page A-35. distance by two.The JAMPOT fan is an overlay template

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A-35

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JAMPOT Fan EffectivenessThe JAMPOT fan is effective only under thefollowing conditions and parameters:

It must be used for frequency modulated voice,amplitude modulated voice, or continuouswave communications in the VHF range.

The enemy target transmitter power outputmust be known.

The enemy transmitter-to-target receiverdistance in kilometers must be known.The jammer location must be known.

The jammer must be located at the sameelevation above the sea level or higher thanthe enemy target transmitter.

A whip antenna must be used with the poweroutput values in Table A-14. (If the LPAantenna is used, divide the values by two.)The jammer power output values obtainedfrom Table A-14 must be read on the jammer’spower output meter.The jammer location must have a reasonableLOS- propagation path to the target receiverlocation with no high hills between the twolocations.

Using the JAMPOT FanTable A-15 is a step-by-step explanation ofhow to use the JAMPOT fan.

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A-37

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A-38

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A-39

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A-40

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Glossary

ACRONYMS AND ABBREVIATIONS

A

acq acquisitionACR armored cavalry regimentADA air defense artilleryAGB advance guard battalionAM amplitude modulatedant antennaAR Army regulationaz azimuth

B

bn battalionBTF battalion task forcebtry batterybw bandwidth

C

C³CM command, control and communicationscountermeasures

CDR commanderCEWOC Communications Electronic Warfare

Operations CourseCOP command and observation postc/s call signCW continuous wave

D

DA Department of the Army

° degree(s)DF direction findingdist distanceDSSB double single sideband

Glossary-1

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E

ECM electronic countermeasureselev elevationESM electronic warfare support measuresET enemy transmitterEW electronic warfareEWS electronic warfare sectionEWTL electronic warfare tasking list

F

f frequencyFLOT forward line of own troops

freq frequencyfield training exerciseFTX

G

G2 Assistant Chief of Staff, G2 (Intelligence)G3 Assistant Chief of Staff, G3 (Operations and Plans)GSRGTA

ground surveillance radargovernment training aid

H

HF high frequencyht heightHTF how to fight

I

IEW intelligence end electronic warfare

K

km kilometer(s)kHz kilohertz

L

loc locationLOS line of sightLPA log periodic array

M

m meter(s)mag magneticMHz megahertzMI military intelligence

N

NCS net control stationnO number

P

pri prioritypwr power

R

recon reconnaiesanceREDTRAIN readiness trainingRX target receiver

S

S3 Operations and Training officer (US Army)

Glossary-2

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SIJ signal initiated jammingSOP standing operating procedureSSB single sideband

TRADOC United States Army Training andDoctrine Command .

TTP tactics, techniques, and procedures

UT

TA target acquisitionTXSC Training Support CenterTC training circularTCAE technical control and analysis elementtgt targetTM technical manualtr target receiver

US United States (of America)USAISD United States Army Intelligence School,

Fort DevensUSATSC United States Army Training Support

Center

V

VHF very high frequency

DEFINITIONS

asset management the planning, directing, andcontrolling of individual intelligence collection,and EW resources necessary for theaccomplishment of the mission

combat information unevaluated data gathered byor provided directly to the tactical commanderbecause of its highly perishable nature or thecriticality of the situation

communication intelligence technical andintelligence information derived from foreigncommunications by other than intendedrecipients

deception measures designed to mislead the enemyby manipulation, distortion, or falsification ofevidence to induce the enemy to react in amanner prejudicial to the enemy's interests

direct support a mission requiring a force to supportanother specific force and authorizing it to answer

directly to the supported force’s request forassistance

Dj jammer location-to-target receiver location distancein km

Dt enemy transmitter location-to-target receiverlocation distance in km

ECM that division of EW involving actions taken toprevent or reduce an enemy’s effective use of theelectromagnetic spectrum

electronic counter-countermeasures that divisionof EW involving actions taken to ensure our owneffective use of electromagnetic radiations despitethe enemy's use of countermeasures

electronic deception the deliberate radiation,reradiation, alteration, suppression, absorption,denial, enhancement, or reflection ofelectromagnetic energy in a manner intended toconvey misleading information and to deny validinformation to an enemy or to enemyelectronics-dependent weapons

Glossary-3

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ESM that division of EW involving actions taken

EW

under the direct command of& operationalcommander to search for, intercept, identify, andlocate sources of radiatad electromagnetic energyfor the purpose of immediate threat recognitionelectronic warfare military action involving theuse of electromagnetic energy to determine,exploit, reduce, or prevent hostile use of theelectromagnetic spectrum, and action whichretains friendly use of the spectrum

general support that support which is given to thesupported force as a whole and not to anyparticular subdivision thereof

Hj elevation of the jammer location above the sealevel in meters

ht elevation of the enemy transmitter location abovethe sea level in meters

intelligence the product resulting from the collection,processing, integration, analysis, evaluation, andinterpretation of available information concerningforeign countries or areas

J jammerjamming the deliberate radiation, reradiation, or

reflection of electromagnetic energy for thepurpose of disrupting enemy use of electronicdevices, equipment, or systems

JAMPOT fan jammer power output mapoverlay-template

K number 2 for jamming FM type receivers

n terrain and ground conductivity factorn=2n=3n=4

n=5

level terrain with good ground conductivityrolling hills with good ground conductivitymoderately rough terrain with fair to good groundconductivityvery rough terrain with poor ground conductivity

Pj minimum amount of jammer power output requiredin watts

Pi power output of the enemy transmitter in watts

Glossary-4

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References

DOCUMENTS NEEDEDThese documents must be available to the (S) FM 34-10A. Division Intelligence and Electronicintended users of this publication. Warfare Operations (U). 15 December 1986.

AR 105-86. Performing Electronic Countermeasures inFM 100-5. Operations. 05 May 1986.

the United States and Canada. 06 December 1978.

READINGS RECOMMENDEDThese sources contain relevant supplementalinformation.

AR 350-3. Tactical Intelligence Readiness Training(REDTRAIN). 20 November 1984.

AR 525-1. Department of the Army Command andControl System. 02 December 1985.

(S) AR 525-22. Electronic Warfare (EW) Policy (U).01 October 1982.

FM 6-20-10. Tactics, Techniques, and Procedures (TTP)for the Targeting Process. 29 March 1990.

FM 6-20-30. TTP for Fire Support for Corps andDivision Operations. 18 October 1989.

AR 525-20. Command, Control and Communications FM 6-20-40. TTP for Fire Support for BrigadeCountermeasures (C³CM) Policy. 01 July 1981. Operations (Heavy). 5 January 1990.

References-1

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FM 6-20-60. TTP for Fire Support for BrigadeOperations (Light). 5 January 1990.

FM 6-121. TTP for Field Artillery Target Acquisition.25 September 1990.

FM 11-50. Combat Communications Within theDivision (Heavy and Light). 4 April 1991.

FM 11-92(HTF). Combat Communications Within theCorps (How to Fight). 01 November 1978.

FM 24-1. Signal Support in the AirLand Battle.15 October 1990.

(C) FM 32-16. ECM Handbook (U). 30 June 1975.

FM 34-1. Intelligence and Electronic WarfareOperations. 02 July 1987.

FM 34-10. Division Intelligence and Electronic WarfareOperations. 25 November 1986.

FM 34-25. Corps Intelligence and Electronic WarfareOperations. 30 September 1987.

FM 34-35. Armored Cavalry Regiment (ACR) andSeparate Brigade Intelligence and ElectronicWarfare Operations. 12 December 1990.

FM 34-80. Brigade and Battalion Intelligence andElectronic Warfare Operations. 15 April 1966.

FM 34-82. Military Intelligence Unit ExerciseDevelopment Guide. 26 November 1985.

FM 71-3. Armored and Mechanized Infantry Brigade.11 May 1988.

FM 71-100. Division Operations. 16 June 1990.

FM 90-2. Battlefield Deception. 30 October 1988.

FM 101-5. Staff Organization and Operations.25 May 1984.

FM 101-5-1. Operational Terms and Symbols.21 October 1985.

References-2

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Index-1

FM 34-40-723 November 1992

By Order of the Secretary of the Army:

MILTON H. HAMILTONAdministrative Assistant to the

Secretary of the Army02821

GORDON R. SULLIVANGeneral, United States Army

Chief of Staff

Official:MILTON H. HAMILTON

Administrative Assistant to theSecretary of the Army

DISTRIBUTION:Active Army, USAR, and ARNG: To be distributed in accordance with DA Form 12-11 E,requirements for FM 34-40-7, Communications Jamming Handbook (Qty rqr block no. 0597).

✰ U.S. GOVERNMENT PRINTING OFFICE : 1994 0 - 300-421 (00147)