Chapter 6
STRYKER DRIVER VISION ENHANCER
AN/VAS-5
Stryker vehicle drivers play a major roll in unit success. To remain combat effective, they must be technically and tactically proficient. To accommodate this, Stryker drivers are trained day and night to operate vehicles in open terrain, on roadways, and in traffic. Stryker vehicle drivers are trained to use the driver vision enhancer (DVE). This chapter explains improvements made to the DVE, introduces new DVE technology, and discusses the modes in which a Stryker DVE can be employed.
INTRODUCTION
6-1. SBCT Soldiers and Stryker crews operate in Iraq around the clock battling enemy forces and the environment in ever-changing hostile conditions. In some instances Stryker crews are forced to operate "buckled-up" (hatches closed) for protection against top attacks when traveling through urban areas. Sniper fire and other threats that affect Soldier and equipment alike are a constant danger. These situations require disciplined Stryker crews who know how to operate with hatches closed. Vision restricted conditions require periscope and video display screen skills that allow day and night maneuver over and around unknown terrain. This section addresses these conditions directly and includes recommended techniques and procedures employed to lessen any apprehension a crew may have when maneuvering "buckled-up".
CAPABILITIES
6-2. The driver vision enhancer (DVE) is a compact, lightweight, uncooled, passive, thermal imaging system designed for use on a variety of combat and tactical wheeled vehicles during darkness or periods of degraded visibility. Battlefield conditions such as smoke, dust, haze, fog, and rain will produce these poor visibility conditions. Under clear atmospheric conditions, the DVE will detect a standing person or a 22-inch (55.9-centimeter) object at a distance of at least 360 feet (110 meters).
6-3. The AN/VAS-5 Stryker DVE provides Stryker drivers with:
l Increased fields-of-view during day/night battle conditions; hatches closed and secured.
l Depth perception.
l Vehicle situational awareness.
l Imagery definition.
l Distance.
l Capability to see during darkness and periods of degraded visibility
l Ability to drive in smoke, dust, haze, and some weather related conditions.
l Ability to drive without emitting visible light or other traceable signal.
NOTE: During periods of degraded visibility or under conditions of low thermal contrast, drivers must use caution and reduce vehicle speed accordingly. A displayed infrared (IR) scene is two-dimensional and does not convey depth perception.
ENVIRONMENTAL CHARACTERISTICS
6-4. The DVE withstands shock or vibration received during normal use, handling, or transportation with no performance degradation, including:
l Ambient Temperature:
n Operating temperature from 120.2 °F (49 °C) to -34.6 °F (-37 °C).
n Storage temperature from 159.8 °F (71 °C) to -50.8 °F (-46 °C).
l Humidity:
n The DVE is not affected by external humidity conditions.
l Corrosion:
n The sensor, display control module, and vehicle adapter are composed of an aluminum alloy that usually does not corrode.
l Altitude:
n The DVE is operable with no performance degradation at altitudes up to 15,000 feet (4.6 kilometers).
OPERATIONAL FEATURES
6-5. AN/VAS-5A DVE equipped Stryker vehicle drivers experience increased maneuver ability while maintaining situational awareness with improvements in field of view (FOV), depth perception, and imagery definition.
Start up time
l Within 3 minutes at: -1 °F TO +120 °F (17 °C TO +49 °C).
l Up to 5 minutes at: -35 °F TO -1 °F (37 °C TO -17 °C)
Field of View (FOV):
l 30 degrees in elevation by 40 degrees in Azimuth.
Target detection
l Under clear atmospheric conditions can detect a person or a 22 inch object at a distance of 360 feet (110 meters) or more.
Focus
l 5 meters to infinity.
Infrared signatures
l Only collects IR energy from field of view.
Visible light
l Ignores visible light input.
l Allows only IR imagery to be seen by operator.
Versatility
l Effective 24 hours a day.
l Enhances vision during poor visibility conditions.
l Able to see camouflaged objects.
Operating temperature
l +120.2 °F TO -34.6 °F (+49 °C TO -37 °C).
DVE optimization goals
l First – Discriminating an object from the field of view background.
l Second – Determining whether the detected object is a hazard, safe path, or obstacle.
n Cliff
n Road
n Boulder
l Third – Negotiating a path around the obstacle.
WARNING
When the DVE is operated in dense fog, IR smoke, or heavy rains, objects may not be readily detectable. If an object has exactly the same temperature as surrounding objects, it may not be readily detectable. Infrared energy cannot be detected through most glass. Operators must therefore maintain an awareness of environmental/weather conditions, and adjust speeds to suit the prevailing operating environment and terrain.
VISUAL VS. VIDEO/THERMAL IMAGES
6-6. Any video image is less clear than a direct visual image. Thermal system images are even less clear.
l In black and white visual images, shades of gray represent brightness of colors.
l In DVE thermal images, shades of gray represent intensity of IR energy.
6-7. Objects that are bright visually are not necessarily bright in thermal imagery. Visual brightness depends on color, visual reflectance of object, and intensity of visual light sources. Distance affects intensity:
l 500 meters: reference
l 1000 meters: 1/4 as intense
l 1500 meters: 1/9 as intense
l 2000 meters: 1/16 as intense
6-8. Thermal image brightness depends mainly on—
l Temperature and emissivity of object (emissivity: rate that material discharges IR energy).
l Intensity and duration of energy sources affecting temperature of object.
l Level, gain, brightness, and polarity settings.
6-9. Glass (windows, headlights) attenuates IR energy and will look cool unless heated or reflecting IR energy of higher intensity. Shadowing in IR images may not be noticeable unless objects have been stationary long enough for the surface to change temperature.
NOTE: Interpretation of thermal image comes with experience and practice.
THERMAL SIGNATURES
6-10. Man-made objects present identifiable thermal signatures because they are different from the natural environment. Objects include:
l Roads and tracks.
l Fences and obstacles.
6-11. Combustion, friction, and body heat provide thermal signatures for mechanical and living objects such as:
l Vehicles (tracks, tires, engines, shock absorbers).
l People and animals.
Concerns
6-12. Geometric and physical conditions can make distinguishing objects in thermal scenes more difficult. Control settings affect image quality. Therefore, time is critical. When conditions obscure thermal scenes drivers should avoid unnecessary adjustments of controls, stop the vehicle, select close and far objects, and adjust DVE controls.
STRYKER WITH AN/VAS-5A (V) DISPLAY MODULE
6-13. The AN/VAS-5 DVE (Figure 6-1) consists of two major assemblies: a display control module (1); and a sensor assembly (2). Mounting of the sensor assembly is based on vehicle designs that provide the greatest amount of operator vision. The unit's improved sensor electronics addresses "thermal wash-out". Stryker DVE sensors are mounted front-center (3) for optimum viewing as shown in Figure 6-2.
3 2 1
Figure 6-1. Sensor modules.
Figure 6-2. DVE sensor location.
NOTE: DVE sensors cannot pan or tilt because they are fix mounted.
Driver vision enhancer (DVE) VIEWING
6-14. Passive night vision devices capture emitted light. Thermal devices capture emitted heat. Thermal imagery is affected by ambient temperatures produced by terrain and man-made objects. Trees, brush, rock, and man-made objects (dwellings, metal material) absorb daytime heat, releasing it after sunset. Large flat surface areas heated by the sun dissipate much faster than natural or man-made objects, releasing their stored heat gradually. Some objects hold heat much longer than others. Rocks for instance, take longer to cool than a tree or a metal object. The more mass, the longer it takes to cool. Weather conditions such as rain, fog, and cold air can also reduce thermal energies.
DVE Appearance
6-15. Objects appear black on the DVE display, making it difficult to determine type, size, and depth.
6-16. To compensate for thermal neutral conditions, drivers can activate the display control module to high gain mode.
6-17. In DVE thermal images (Figures 6-3 through 6-7), shades of gray represent intensity of IR energy. Thermal image brightness depends mainly on:
l Temperature and emissivity of object.
l Intensity and duration of energy sources affecting temperature of object.
l Contrast, brightness, and polarity settings.
NOTE: Although actual photographs are not the thermal images shown in figures 6-3 through 6-7, they do offer a comparison of real time vs. projected thermal images as seen by the driver.
6-18. Figure 6-3 illustrates visual vs. thermal discrimination of natural objects.
Figure 6-3. Visual vs. DVE thermal discrimination of natural objects.
6-19. Figure 6-4 illustrates visual vs. thermal discrimination of man-made objects.
Figure 6-4. Visual vs. thermal discrimination of man-made objects.
6-20. Figure 6-5 illustrates distance vs. thermal intensity.
Figure 6-5. Distance vs. thermal intensity.
6-21. Figure 6-6 illustrates visual vs. thermal viewing angle intensity.
Figure 6-6. Visual vs. thermal viewing angle intensity.
6-22. Figure 6-7 illustrates atmospheric turbulence vs. thermal signatures.
Figure 6-7. Atmospheric turbulence vs. thermal signatures.
CROSSOVER PERIODS
6-23. There are two short periods each day called "crossover periods" when most natural objects are essentially the same temperature: when they cool down at night, and when they heat up in the early morning. Since objects are near the same temperature during these periods, the image display quality is degraded because there is not much temperature difference the DVE can distinguish. This also happens when a heavy rain makes all natural objects close to the same temperature.
6-24. Crossover periods are a daily cycle in which objects are heated by sun then cool down at night.
l Sunrise: Objects begin to absorb thermal energy and increase in temperature.
l Sunset: Objects begin to lose thermal energy and decrease in temperature.
6-25. Motionless objects or things not generating their own thermal energy approach the same temperature. Such objects include:
l Large dense objects (stationary vehicles) heat and cool slowly.
l Lightweight objects (foliage) heat and cool quickly.
l Heavy objects that have high thermal mass.
l Lightweight objects that have low thermal mass.
6-26. An overcast sky reduces solar energy absorbed by objects. Surface temperatures under this condition tend to become equal, causing reduced contrast particulates (dust, haze, smog, smoke). This degrades DVE imagery. How much degradation occurs depends on size, type, and concentration of particles.
6-27. High humidity produces surface reflections that can cause deceptive imagery. Example: Smooth, glossy surfaces (windows, mirrors, still water) can produce strong reflections of IR light from other sources. This is generally not a problem, but if occurs it can be deceiving.
OPERATIONAL CONSIDERATIONS
6-28. Time is critical on a battlefield, so training and practice is important. Well-trained drivers can avoid any unnecessary trial and error adjusting of controls when the enemy is near. Wet weather also has a significant effect on DVE thermal imagery. It cools down objects, creates fog or clouds, and degrades IR energy. "Thermal washout" can occur during periods of heavy rain. All terrain features, natural and man-made, approach the same temperature (thermal neutral conditions) during heavy rains, affecting DVE thermal images in the following ways:
l Light rain ® Slight degradation
l Medium rain ® Medium degradation
l Cloudburst ® Heavy degradation
l Long duration rain storms ® Heavy degradation
n All objects approach the same temperature creating thermal neutral conditions
NOTE: Thermal imagers are slightly better than visual optics during wet weather conditions. DVE high gain feature improves thermal image in these conditions.
DRIVER TACTICS, TECHNIQUES, AND PROCEDURES
6-29. "Drivers must be tactically and technically proficient" was a valuable lesson learned (and relearned) by maneuvering commanders in the beginning of Operation Iraqi Freedom. Drivers involved in convoy operations must constantly remain alert for ambushes, maneuver tactically to support by fire, and at times, use their vehicles as shields to protect ground warriors. Most driver training beyond basic driving skills consists of on the job training experience. But lessons learned yesterday give us an edge in training today.
6-30. Driver training should progress from basic to advanced stages.
l Basic skills consist of maneuvering from an open hatch position, on and off road, during normal conditions.
l Advance skills consist of maneuvering with hatch closed, navigating using the DVE, on and off road, during day/night conditions.
NOTE: Leaders should take advantage of inclement weather conditions to acclimate drivers.
6-31. Driving a Stryker "buttoned-up" while depending on the DVE for navigation can be a discriminator in driver selection. Not everyone can do it. Some Soldiers become claustrophobic; others become indecisive. Therefore, testing Soldier ability to adapt to enclosed navigation conditions while using the DVE should be conducted as part of basic driver training.
NOTE: For safety purposes, "buttoned-up" DVE training should be performed in a controlled environment.
6-32. Advanced training should include:
l Driving cross-country, day and night. Drivers can recognize and navigate terrain features, and select routes that offer cover and concealment.
l Driving in traffic, day and night. Driving in traffic helps with depth perception between vehicles, especially when performing convoy operations where speeds change constantly and can stop with no warning. This training should be closely monitored by vehicle commanders and performed in a controlled environment.
l Driving on urban terrain. Drivers face numerous obstacles that require superior navigation skills on urban terrain. Moving on unknown rubbled urban terrain congested with conveyances and people requires experience, patience, and quick reflexes.
6-33. Commanders should design driver courses that test Soldier maneuver skills on and off road. Courses should provide areas that test reaction to enemy ambush, direct, and indirect fires. Use of OIF Lessons Learned should serve as the basis of course design. To accommodate this developers should—
l Set up road cone and engineer tape lined driving lanes to test stand-off between other vehicles and perform urban terrain vehicle turns.
l Test convoy driving at every opportunity.
l Test Soldier reactions using simulators and simulations.
l Test crew/squad actions on contact.
NOTE: Stryker DVE sensors give drivers maximum fields of view of direction of travel. Portions of the left front corner and most of the right front corner cannot be observed. To overcome these blind spots vehicle crew members must assist drivers in navigating obstacles and making turns, particularly in complex and restricted terrain.
DRIVER DUTIES AND RESPONSIBILITIES
6-34. Stryker drivers must possess extraordinary driving skills. They must be technically and tactically proficient to maneuver on today's varying operational terrain. We sometimes take our drivers for granted. They do their job so well we have tendencies to forget that they have been driving for hours and need rest.
Driver Fatigue
6-35. When fatigued, driver communications may seem at a loss. Driving mistakes such as erratic speed (up and down) and weaving (left to right) may also be noticed. These are just three trigger points that can indicate a driver is tired.
DVE Fatigue
6-36. Drivers can become so mentally fatigued from watching the DVE while navigating over unknown terrain during night or environmental conditions (natural and man-made) that they can lose their sense of reality.
Convoy and DVE Fatigue
6-37. Driver fatigue is more prevalent during convoy operations than it is during area presence patrols. Staring hour-after-hour at the back of another vehicle can be hypnotic, making driver reaction and reflex actions slow and lethargic. The problem is compounded when drivers are forced to navigate using the DVE with hatches closed. Rotating drivers regularly can solve these driver fatigue problems, but it is not always possible. The next best option is planning stops to rest drivers at every opportunity.
Duties and Responsibilities
6-38. Each licensed operator of a vehicle or piece of equipment is expected to—
l Operate vehicles or equipment in a safe and prudent manner.
l Report unsafe operating conditions of vehicles or equipment.
l Report all accidents to his or her supervisor and to the motor pool that dispatched the equipment.
l Comply with all municipal, state, and military motor vehicle or equipment regulations, as required.
l Ensure cargo (including personnel) is properly loaded, secured, and protected from the elements prior to transport.
l Ensure vehicles and equipment is properly secured when left unattended.
l Wear installed restraint systems.
l Back vehicles and use ground guides according to the provisions of AR 385-55 and FM 21-305.
l Inform supervisors if using medication that may adversely affect vision/coordination or cause drowsiness.
l Perform operated equipment inspections before, during, and after operations.
l Follow all operator maintenance outlined in appropriate equipment technical manuals.
l Care for and clean vehicle equipment, tools, and components.
l Ensure vehicles or equipment is properly serviced.
l Ensure security of the vehicle, cargo, and tools.
l At all times, exercise common sense.
DRIVING with the DVE
6-39. Excellent DVE skills are essential for fast and effective combat maneuver. Regular practice of DVE procedures enable Stryker operators to retain DVE navigation skills necessary during limited visibility conditions. The following Stryker DVE driving tips should be considered when maneuvering.
l Do not make DVE adjustments while moving, if image becomes degraded, or when you feel unsafe with the driving situation.
(1) Notify chain of command of difficulties. Stop and make adjustments to correct the problem, when possible.
(2) Select and focus on long distance objects, then select close objects to confirm focus, contrast, and brightness of thermal signatures.
l Drive only in the locked azimuth (AZ) and elevation (EL) (level zero degree) position. This provides the greatest range of motion between zero degrees and maximum AZ and EL positions.
l Maintain a safe distance between vehicles during convoy operations.
n Distance between vehicles is METT-TC dependant.
n Too much experience is sometimes worse than too little experience.
n More experienced drivers may push the envelope during movements.
n Less experienced drivers may become too cautious.
n Practice is the only answer to fluid movements in battlefield conditions.
l Do not "OUTDRIVE" the DVE.
(1) Overlooking upcoming hazards can result from looking too far down course.
(2) Not enough time for hazard reaction can result from driving too fast.
l Making turns using the DVE. Because the DVE looks forward, intersecting pathways will disappear from the driver's FOV prior to the vehicle exiting the intersection.
(1) Turning technique. Slow the vehicle to a comfortable turning speed. As the pathway passes off of display, begin counting five seconds (down to one from five), then begin turn.
(2) Adjust turn rate as path comes back into view on display.
(3) Adjust count as necessary considering speed turn rate.
DRIVING CONDITIONS
6-40. Optical systems cannot overcome all natural and man-made battlefield conditions, and the odds of a unit operating within conditions that defeat DVE capabilities are not high (7 percent). Strykers outfitted with the AN/VAS-5 have lowered the possibility of defeating the DVE to around 4 percent. The addition of a "high gain mode" feature further reduces the possibility of thermal washout.
6-41. Skills required for operating the DVE are essential for fast and effective use during combat. Regular practices of these procedures help Stryker operators retain the skills necessary to navigate using the DVE. Refer to the driving steps above for all-weather driving conditions.
DRIVING CROSS-COUNTRY
6-42. Today's DVE is much different than "image intensifying" night vision devices of the past. The DVE's thermal capability provides unparalleled flexibility for driving in either day or night conditions. However, it does not provide the depth perception of the human eye. Therefore, when driving in missions involving cross-country terrain, drivers must pay full attention to potential terrain hazards such as:
l Drop-offs.
l Ditches.
l Ravines.
l Eroded "wash-outs".
6-43. These areas generally look darker than the surrounding terrain and can be anywhere from difficult to impossible to determine the depth of the drop. When encountering a suspected drop-off or ditch, drivers should stop prior to the feature (if tactically feasible) and have a ground-guide direct the vehicle around or through the feature. If a ground-guide is not tactically feasible, unknown areas should be approached slowly with caution while adhering to the prescribed vehicle cant.
NOTE: Strykers are naturally top-heavy and not as sure footed as a flat track vehicle. Adding protective armor makes them even more susceptible to tilt and slide on sloping terrain.
6-44. Although reactive armor provides more protection than a slat-armored cage, slat armor does have a proven record of protecting Stryker vehicles from RPGs. In Iraq, the Stryker's unique operational capabilities and its mission-support role required little change in Infantry tactics. However, the addition of protective armor increased the overall weight and width of the Stryker, affecting its maneuverability on and off road. Other effects are added fuel usage, reduction in speed when crossing obstacles and traveling on roadways, and excessive wear and tear on tires and the suspension system.
6-45. Listed below are 11 considerations for Stryker crews operating with reactive or slat armor.
(1) Weight affects the cant of a vehicle, so move slowly over rolling terrain.
(2) Always be mindful of the added weight, height, and width of the Stryker when selecting routes.
(3) Stay off road shoulders as vehicles are susceptible to rolling over.
(4) Drive up or down the forward slope of hills, never along the side of hills.
(5) Search out hardpan surfaces.
(6) If forced to travel over soft ground, stay at one steady speed to avoid bogging down.
(7) Avoid hills and gullies to lessen strain on the power pack and suspension system.
(8) Set tire pressure in accordance with Stryker technical manuals for on- and off-road operation to lessen wear and tear on tires and the suspension system. Low tire pressure is better when traveling on soft terrain. Normal tire pressure is better when on hard surfaces. The driver must make adjustments to the height management system when moving from hard service roads to off-road surfaces to keep wheels from rubbing the hull.
(9) Go around obstacles when possible.
(10) Operational time and distance must be considered when reactive or slat armor is installed. Set up petroleum, oil, and lubricant (POL) resupply points to account for additional fuel use due to additional weight. Also consider reducing speed to lessen fuel consumption and damage to suspension systems.
(11) Send out reconnaissance teams to check bridge crossings. Some have single lanes, most have two, few have more than two. Strykers with reactive armor or slat will in most cases be too heavy or wide to cross. Use ground Soldiers to provide security to the entrance and exit points of bridges. Have VCs ground-guide Strykers across, especially during hours of limited visibility.
DRIVING ON URBAN TERRAIN
6-46. Drivers must pay special attention to street widths and associated traffic (vehicle or pedestrian) in urban or congested areas, and adjust speed for driving with the DVE. A technique for driving in the urban environment is to develop vision "zones" for reacting to potential hazards. For example, the "Four Second Stopping Zone" can be applied by locating an object to the vehicle front and giving a count of four. Four seconds is the amount of time it takes for the vehicle to reach the object. The four-count times the distance in which the vehicle should be able to stop in case of an emergency situation (unexpected obstacles, civilian cross traffic pulling into the driving lane). The four seconds is based on densely populated areas and can be adjusted for greater traffic speeds in less populated areas. When conducting convoy operations, the stopping zone can be extended to prevent convoy vehicles from bunching up.
6-47. Another challenge to driving with the DVE in urban operations is peripheral view. Assistance may be required from the VC wearing night vision goggles in poorly lit areas to observe objects to the sides of the vehicle. The VC will also communicate with a trail vehicle, especially if his vehicle is required to drive in reverse. These situations should be practiced prior to performing vehicle maneuvers, especially when the DVE is the only means of navigation.
ALL-AROUND SECURITY
6-48. Hatch locations, the remote weapons station (RWS), and protective armor limits all members of the crew the advantage of a 360-degree, clear field of view—with hatches open and Soldiers up. But all-around security is possible when moving with crews or squads onboard by positioning them in the following manner.
l From Mid-Deck Forward. VCs view from mid-deck forward. The location of the RWS interferes with total VC viewing of the left side forward to the left corner of the Stryker.
l From Left Side to Front-Center. Crew/squad leaders view from the left side to front-center of the Stryker, covering the area of the VC's field of view that the RWS interferes with.
l From Mid-Deck Back. Crew/squad members view from mid-deck back.
l From the Ground. Soldiers and other Strykers will provide vehicle security when they are on the ground.
NOTE: Prior to movement the VC should move around the outside of the Stryker to locate and note those portions of the vehicle that cannot be observed when the hatches are open and when they are closed. This should be done from all top hatches (driver, RWS, squad leader position, and troop hatches).