Attachment 01 FWS-I Performance Specification FRP-PRF-FWSI (2 FEB 2021).docx

Appendix I

METRIC FRP-PRF-FWSI-GEN (DRAFT)

2 FEB 2021

PERFORMANCE SPECIFICATION FOR

FAMILY OF WEAPON SIGHTS – INDIVIDUAL (FWS-I) VARIANT

This Performance Specification is approved for use by Program Executive Office Soldier, Department of the Army, and is available for use by all Departments and Agencies of the Department of Defense.

1. SCOPE.

1.1 Scope. This Performance Specification establishes the performance, design, test, manufacture, and acceptance requirements for the Family of Weapon Sights – Individual (FWS-I) variant. The FWS-I shall be a lightweight, modular, self-contained, battery operated, thermal imaging system for surveillance and target acquisition of the M4 Carbine*, M16A2/M16A4 Rifles*, M249 Squad Automatic Weapon (SAW), M136 AT4, and M141 Bunker Defeat Munition (BDM) and objectively the Squad Designated Marksman Rifle (SDMR), Next Generation Squad Weapon-Rifle and Automatic Rifle (NGSW-R/AR), during daylight, darkness, adverse weather, and dirty battlefield conditions. It shall provide a Rapid Target Acquisition (RTA) capability when used in conjunction with an ISW ICD headset, an in-line (clip-on) weapon sight capability when used in conjunction with the M150 Rifle Combat Optic (RCO), the M68 Close Combat Optic (CCO), and the Next Generation Squad Weapon-Fire Control (NGSW-FC), and a standalone weapon sight capability. The FWS-I shall be used without having to remove the RCO or CCO, therefore allowing the same aiming tactics, techniques, and procedures (TTPs) and eliminating the need to re-zero. The RTA capability enables rapid offensive targeting during Close Quarters Battle (CQB), in all battlefield conditions, by reducing target acquisition and engagement timelines, without the use of active lasers.

Notes: * The M203/M320 grenade launchers may be mounted on the underside of the M4/ M16.

DISTRIBUTION STATEMENT C. Distribution is authorized to U.S. Government Agencies and their contractors for official use or for administrative and operational use. Other requests for this document shall be referred to PdM Soldier Maneuver Sensors, ATTN: SFAE-SDR-SMPT-SMS, 10125 Kingman Road Building 317, Building 359, Fort Belvoir, VA 22060.

Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be sent to: Product Manager Soldier Maneuver Sensors, ATTN: SFAE-SDR-SMPT-SMS, 10125 Kingman Road Building 317, Fort Belvoir, VA 22060.

Draft Family of Weapons Sights Specification

2. APPLICABLE DOCUMENTS.

2.1 General. The documents listed in this section are needed to meet the requirements specified in section 3 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet the requirements in all documents cited throughout this specification, whether or not they are listed in this section.

2.2 Government documents.

2.2.1 Specifications, standards and handbooks. The following specifications, standards and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are the Department of Defense Index of Specifications and Standards (DODISS) and supplement thereto, cited in solicitation.

SPECIFICATIONS

STANDARDS

MIL-STD-129 Military Marking for Shipment and Storage MIL-STD-130 Identification Marking of US Military Property

Processing Standards Publication 140

FEDERAL

FED-STD-595C Colors Used in Government Procurement

Unless otherwise indicated, copies of federal and military specifications, standards, and handbooks are available for the Standardization Document Order Desk, 700 Robbins Avenue, Building #4, Section D, Philadelphia, PA 19111-5094.

2.2.2 Other Government documents, drawings and publications. The following other Government documents, drawings and publications form a part of this document to the extent specified herein. Unless otherwise specified, the issues are those cited in the solicitation.

DOCUMENT

Criteria

Systems and Organizations

DRAWINGS

(Copies of specifications, standards, drawings, and publications required by suppliers in connection with specified procurement functions should be obtained from the procuring activity or as directed by the contracting officer.)

2.3 Non-Government publications. The following documents form a part of this specification to the extent specified herein. Unless otherwise specified, the issues of the documents that are DOD- adopted are those listed in the issue of the Department of Defense Index of Specifications and Standards (DODISS) cited in the solicitation. Unless otherwise specified, the issues of documents not listed in the DODISS are the issues of the documents cited in the solicitation.

AMERICAN NATIONAL STANDARDS INSTITUTE

ANSI/ASQ Z1.4-2008 Sampling Procedures and Tables for Inspection by Attributes

ANSI/EIA/TIA-232-F-1997 Interface Between Data Terminal Equipment and Data Circuit- Terminating Equipment Employing Serial Binary Data Interchange, dated 30 September 1997

ANSI/TIA/EIA-422-B-1994 Electrical Characteristics of Balanced Voltage Digital Interface Circuits, dated April 13, 1994, reaffirmed January 27, 2000 (Copies available via World Wide Web at http://www.ansi.org)

SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS (SMPTE)

SMPTE 170M SMPTE Standard for Composite Analog Video Signal NTSC for Studio Applications: dated 1999 (Application for copies should be addressed to Society of Motion Picture and Television Engineers (SMPTE), 595 W. Hartsdale Avenue, White Plains, NY 10607)

2.4 Order of precedence. In the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.

3. REQUIREMENTS.

3.1 Item definition.

The FWS-I shall be a lightweight, modular, self-contained, battery operated, thermal imaging system for surveillance and target acquisition of individual weapons during daylight, darkness, adverse weather and dirty battlefield conditions.

The FWS-I, when used in conjunction with a Direct View Optic (DVO), shall provide interconnectivity such that the FWS-I displayed output scene imagery serves as the input for the DVO.

The FWS-I, when used in conjunction with an ISW ICD headset shall provide a Rapid Target Acquisition (RTA) capability. RTA is the capability to view the boresighted/zeroed weapon sight reticle in the ISW ICD headset display, enabling the Soldier to accurately engage targets without the use of active lasers. There are multiple RTA modes: partial weapon sight imagery with reticle spatially aligned with the thermal imagery of the ISW ICD headset, full weapon sight imagery with weapon sight reticle displayed in the ISW ICD headset, simultaneous display of full weapon sight imagery with weapon sight reticle and ISW ICD headset imagery or picture-in-picture (PiP), and a bore-sighted reticle spatially aligned with the thermal imagery of the ISW ICD headset (objective). In all modes, data from other devices such range finders and Global Positioning Systems (GPS) shall also be displayed in ISW ICD headset display. The RTA capability shall be provided wirelessly.

Unless otherwise stated, all FWS-I related requirement specifications apply when the FWS-I is used in a stand-alone capacity

3.2 Component list. Each FWS-I shall consist of all of the following items:

3.2.1 Major component list.

a. Weapon Sight

i. Thermal Sensor

ii. Shutter Assembly

iii. Objective Lens Assembly

iv. Eyepiece

v. Display

vi. System Electronics

vii. Housing

viii. Power Source

ix. Wireless Transceiver

x. Antenna

xi. Tilt and/or Motion Sensors

b. Tethered Remote

3.2.2 Ancillary items.

a. Objective Lens Cover (captured)

b. Mount Assembly (installed) (TWS Mount Assembly [80063-A3301511] or a functional, suitable, and effective alternative)

c. Carrying Case

d. Transit/Storage Case or a Commercially Acceptable Container

e. Operator Manual

f. Quick Reference Card (waterproof)

g. Lens Cleaning Material

h. Eyecup (removable)

i. One (1) M68/M150 Coupling Shroud (removable)

j. Operator Installed/Removable Spacer (if required)

3.3 Characteristics.

3.3.1 Weapon Sight Performance characteristics. The FWS-I shall meet all requirements specified herein without damage (3.6.1) or degradation of performance (3.6.2) over all environmental conditions, including weapon firing on interfacing weapons employed by soldiers (3.3.8).

3.3.1.1 Target Recognition.

3.3.1.1.1 Target Recognition Requirements. The FWS-I shall provide the following minimum capabilities. Electronic zoom shall not be used to meet the specified range requirements.

3.3.1.1.1.1. (KPP) Clear-Air Target Recognition. FWS-I shall have a 70% or greater probability of recognizing a personnel-sized target (upright moving man) out to a range of 960 meters (T), and 1200 meters (O) during night engagements in atmospheric conditions which provide seven kilometer visibility along an unobstructed line of sight (3.6.22). The FWS-I in clip-on mode must enable the Soldier to recognize a personnel-sized target (upright moving man) 70% of the time out to 960 meters (O). The FWS-I, while in spatially aligned RTA mode (3.3.2.1.1), shall have an 80% or greater probability of recognizing a personnel-sized target (upright moving man) out to a range of 300 meters (T), and 480 meters (O) during night engagements in atmospheric conditions which provide seven kilometer visibility along an unobstructed line of sight (3.6.22).

3.3.1.1.1.2. (KPP) Obscured Target Recognition. FWS-I shall have a 90 percent or greater probability of recognizing a personnel-sized target (upright moving man) out to a range of 300 meters (T), and 480 meters (O) in dirty battlefield conditions (3.6.20) and adverse weather (3.6.19). The FWS-I in clip-on mode must enable the Soldier to recognize a personnel-sized target (upright moving man) 90% of the time out to 300 meters (T), and 480 meters (O). FWS-I while in spatially aligned RTA mode (3.3.2.1.1) shall have a 90 percent or greater probability of recognizing a personnel-sized target (upright moving man) out to a range of 50 meters (T), and 150 meters (O) in dirty battlefield conditions (3.6.20) and adverse weather (3.6.19).

3.3.1.1.1.3. Target data requirements. The following target data shall be used for all requirements in 3.3.1.1.1.1 and 3.3.1.1.1.2:

a. Target Contrast (RSS): 2.0 Delta Kelvin

b. Target Size: Square Root Target Area = 0.75 meters

c. Display Brightness: 4.2ftL

d. V50 Recognition: 1.53 cycles

e. Model Version: NVThermIP dated August 2009

3.3.1.2 Minimum Resolvable Temperature (MRT). The two dimensional MRT (3.6.13) shall not exceed the values listed below in Table 3.3.1.2-1. The below-listed MRT requirements are a composite of the vertical and horizontal MRT. Temperature differences at the nominal % Nyquist frequencies based on focal length and pixel pitch should be encapsulated in the spatial frequencies in Table 3.3.1.2-1.

Table 3.3.1.2-1. FWS-I MRT Requirements

3.3.1.3 Image characteristics.

3.3.1.3.1 Image uniformity. Both large and small area uniformity requirements specified below (3.3.1.3.1.1 to 3.3.1.3.1.4) shall be measured using the methodology described in Appendix B with the sensor viewing a uniform irradiance background having a temperature difference between -30°C and +30°C from the ambient air condition over the specified operating temperature extremes (Table 3.3.1.3.1‑1). The image uniformity shall be measured using both a digital output from the thermal sensor and measured viewing the display through the eyepiece.

Table 3.3.1.3.1-1. Image Uniformity Test Conditions

3.3.1.3.1.1 Thermal Sensor Large area uniformity. The video level shall not vary from the average level by more than 2.0C over the entire field of view (3.6.6), and shall not vary by more than 0.7°C over the average level in the critical display area (Region 1 of Figure E.1 of Appendix E) following an internal NUC calibration (3.6.4).

3.3.1.3.1.2 Thermal Sensor Small area uniformity. The video level, in any local area (3.6.5), shall not vary by more than 0.5C from the average level of the local area following an internal NUC calibration (3.6.4).

3.3.1.3.1.3 Display Level Large Area Uniformity. With the thermal channel display brightness at 10fL when measured through the eyepiece, the display brightness shall not vary from the average display brightness by more than 30% over the entire field of view (3.6.6), and shall not vary by more than 15% over the average level in the critical display area (Region 1 of Figure E.1 of Appendix E) following an internal NUC calibration (3.6.4).

3.3.1.3.1.4 Display Level Small Area Uniformity. With the thermal channel display brightness at 10fL when measured through the eyepiece, the display brightness in any local area (3.6.5) shall not vary by more than 10% from the average level of the local area following an internal NUC calibration (3.6.4).

3.3.1.3.2 Image quality.

3.3.1.3.2.1 Visual image quality. Spurious images and noise patterns shall not be discernible over the entire field of view (3.6.6). Spurious images from targets or symbology shall not detract from normal operation or degrade functionality. There shall be no discernible image persistence, pulsing, or vibration. There shall be no perceptible rotation of the scene. The FWS-I shall provide imagery to the operator that does not exhibit any visible level of flicker, flashing (3.6.18), image artifacts or intermittent operation under all operational conditions. The FWS-I shall not be significantly affected by the operational characteristic of the host weapon. Momentary image “upsets” during weapon fire are not considered significant if there is no operational impact. Momentary image “upsets” less than 200 ms in duration from the last round fired shall be allowed.

3.3.1.3.2.2 Signal Transfer Function (SiTF). All image quality scenarios shall be met using any image processing that could be deployed to automatically adjust the imagery for display to an observer and shall be performed using the methodology described in Appendix D.

3.3.1.3.2.3 Automatic Gain and Level Freeze. The FWS-I shall freeze automated gain and level settings during weapon firing if required to preclude muzzle flash from degrading image quality and target acquisition.

3.3.1.3.2.4 Automatic Gain and Level Regions of Interest. The FWS-I shall provide a minimum of two user selectable automatic gain and level calculation regions of interest. One region of interest shall utilize the entire scene to calculate the automatic gain and level. A second region of interest shall exclude the effects of the horizon (top 10-25% of the vertical FOV), the effects of barrel heating (bottom 10-25% of the vertical FOV), and utilize at least the center 50% of the vertical and horizontal FOVs to calculate the automatic gain and level.

3.3.1.3.3 No-Information/Defective Pixels.

3.3.1.3.3.1 No-Information Pixels for Sensor. This requirement applies to the FWS-I sensor defective channels and pixels at the focal plane array (FPA) output before uniformity correction/ normalization. The FWS-I shall meet the no-information pixel (3.6.7) requirements specified in Appendix E.

3.3.1.3.3.2 Display Defective Pixel. The FWS-I display shall meet the defective pixel (3.6.30) requirements specified in Appendix E.

3.3.1.3.3.3 Defective/No information pixels. No-information pixels (3.6.7) shall be substituted with information from nearby pixels to minimize visibility to the operator. The FWS-I shall conform to the defective/no information pixel requirements of Appendix E.

3.3.1.3.4 Frame rate. The FWS-I system sensor and display shall each have the same frame rate of no less than 30.0 Hz ± 0.1 Hz (threshold) and 60.0 Hz ± 0.1 Hz (objective).

3.3.1.3.5 Distortion. The FWS-I shall have an end-to-end system level distortion (3.6.8.1) of less than 0.5 percent inside the critical display area (Region 1 of Figure E.1 of Appendix E), and less than 1 percent outside the critical display area. The optical distortion of the eyepiece (3.6.8.2) shall be less than 2 percent across the field of view. This condition shall be met at all objective lens focus positions.

3.3.1.3.6 Temporal 3D Noise. The FWS-I shall have a temporal 3D noise (square root of the sum of the squares of TVH, T, TV, and TH) of no greater than 0.09C following an internal NUC calibration (3.6.4). The temporal 3D noise measurement shall be performed at 20° C +/- 5° C with a scene delta temperature of 0° C and normalized at the frame rate of the system (3.3.1.3.4) and over the 7-14um waveband.

3.3.1.3.7 Fixed Pattern Spatial Noise. The pre-sample spatial noise (VH, V, and H) shall not degrade system performance more than the requirements stated in Table 3.3.1.3.7-1 following an internal NUC calibration (3.6.4). The pre-sample is defined as the objective optic, the detector array, and thermal electronics measured via the digital output port.

Table 3.3.1.3.7-1. Spatial Noise

3.3.1.3.8 Total Thermal Time Constant. The FWS-I total thermal time constant, to include thermal sensor and electronic time constants, shall be 14.0 ms. This requirement shall be validated in accordance with Appendix I.

3.3.1.3.9 (KPP) System Magnification. In order to support the clip on configuration, The FWS-I shall have a paraxial system magnification of 1.0 +/- 2.5%.

3.3.1.3.10 Weapon Sight Latency. The latency of the weapon sight shall be less than or equal to 32 ms. The weapon sight latency measurement begins when the energy is detected by the FWS-I thermal sensor and ends when the image viewed on the FWS-I display.

3.3.1.4 Reflection. The FWS-I shall prevent the operator’s position from being revealed by providing a flat, non-specular finish on all external surfaces, except for the optical elements.

3.3.1.4.1 Anti-reflection. The FWS-I shall provide mechanical features for the attachment of an anti-reflection device on the Objective Lens Assembly.

3.3.1.5 (KPP) Field-of-View (FOV). The FWS-I shall have a minimum horizontal FOV of 18 degrees, with a horizontal Narrow Field-of-View (NFOV) one-third the WFOV. The NFOV shall be centered in accordance with 3.3.3.13.8. There is no NFOV option available when the FWS-I is used in conjunction with a DVO. NFOV and indicator line widths shall be in accordance with 3.3.3.13.1. The electronic zoom shall not be used to satisfy the range requirements.

3.3.1.5.1 FOV change time. FOV change shall be accomplished in less than one second from initiation of the change, including video settling time.

3.3.1.5.2 FOV interalignment. For the FWS-I in standalone mode and with the reticle position indicator at zero/zero, a target in the center of the wide field of view optics shall be within 1 IFOV of the center of the narrow field of view when switching to the smaller field of view. The IFOV (Instantaneous Field of View) is defined as the angular projection of the center display pixel in target space.

3.3.1.5.3 FOV focus retention. For a variable focus system, once the FWS-I has been initially focused in the NFOV at any range, no further focus adjustment shall be necessary when switching back and forth between the NFOV and WFOVs at that range. The point at which refocusing is necessary shall be in accordance with the requirements of 3.3.1.10.

3.3.1.5.4 FOV change effect on display image. The video presented at the display or output of the system shall be interrupted for no more than one second during FOV change.

3.3.1.5.5 FOV tolerance. The system level FOV shall not vary more than plus or minus four percent of the FOV. The range of acceptable FOV values, including tolerances, is required to be greater than the minimum FOV requirement stated in 3.3.1.5.

3.3.1.6 Operational readiness. Over the full operating temperature range of 3.3.8.2, the FWS-I shall provide a recognizable image within 40 seconds after FWS-I power is applied. Over the full operating temperature range of 3.3.8.2, the FWS-I shall provide a recognizable image within 1.5 seconds after being switched from standby to full-on. The image is recognizable if an observer is able to resolve the middle spatial frequency 4 bar target called out in Table 3.3.1.2-1, set at twice the specified temperature. The functioning of standby mode is described in Section 3.3.3.14.7.

3.3.1.7 Light security.

3.3.1.7.1 Light security (standalone mode). The FWS-I shall not emit visible light detectable by the unaided human eye at a distance greater than or equal to 5 meters under all scene lighting conditions when used by a soldier (not wearing a protective mask, protective eyewear, eyeglasses, or goggles).

3.3.1.7.1.1 Eyecup. The eyecup used for light security shall be replaceable at the user level and have a positive locking feature that prevents against accidental removal of the eyecup in all operational environments.

3.3.1.7.2 Light security (clip-on mode). The FWS-I, when used in conjunction with a DVO, shall not emit visible light from the FWS-I/DVO "coupled" interface which is detectable by the unaided human eye at a distance greater than or equal to 5 meters under all scene lighting conditions.

3.3.1.8 Audio security. For any operations not induced by the warfighter, including shutter actuation, the FWS-I shall meet the Level II Aural Nondetectability requirements for 5 meters nondetectability as specified in Requirement 2 of MIL-STD-1474E under all operating conditions when measured in 8 locations, 45 degrees apart with the starting point being the optical axis on the objective side of the FWS-I system. The acoustic noise level produced by the FWS-I during user operation, including actuation of all switches, controls (including focus), and buttons on the sight and the tethered remote, shall be less than or equal to 30 dBA at a distance of 5 meters (Table C-1 of Appendix C). Operation of the battery compartment and the rail grabber are exempt from this noise limit.

3.3.1.9 Eyepiece.

3.3.1.9.1 FWS-I Eyepiece. The FWS-I eyepiece, when used in conjunction with a DVO, shall be designed to be optimized for the systems included in Table 3.3.1.9.1-1:

Table 3.3.1.9.1-1. FWS-I Optimized Direct View Optic

3.3.1.9.1.1 Standalone Mode. There shall be no luminance vignetting at the on-axis position within a 5mm diameter pupil. The pupil shall be located at a flange distance greater than 30mm from the eyepiece and offset by 2.5mm from the optical axis of the eyepiece in a plane normal to the eyepiece’s optical axis. At a field angle of ±7.0 degrees the relative illumination shall be no less than 80% percent.

3.3.1.9.1.2 NGSW-FC / CCO Mode. There shall be no luminance vignetting at the on-axis position within a 5mm diameter pupil. The pupil shall be located at a distance of 63mm from the CCO and offset by 2.5mm from the optical axis of the eyepiece in a plane normal to the eyepiece’s optical axis. At a field angle of ±3.5 degrees the relative illumination shall be no less than 60 percent.

3.3.1.9.1.3 RCO Mode. Within a 30 mm diameter pupil located at a flange distance of greater than 30mm from the eyepiece, there shall be no luminance vignetting at the on-axis position (field angle of zero degrees). At a field angle of ±3.5 degrees the relative illumination shall be no less than 90 percent. The pupil shall be in a plane normal to the eyepiece's optical axis.

3.3.1.10 Focus Range. The FWS-I shall have a minimum focus of 5 meters (T), 1 meter (O), and shall maintain boresight (3.6.14) through the focus range. All focus adjustment rings shall be continuously adjustable. Focus rings shall allow for adjustment using one hand. Minimum focus range shall have a modulation transfer function of greater than 10% at one half the detector cutoff (i.e. half Nyquist) frequency.

3.3.1.11 Response outside FOV. The response of the FWS-I to sources of radiation (T=1000C) outside the displayed FOV by more than 0.5shall not vary the luminance value by more than the square root of two over the total range of operator controls:

L2 < L1*SQRT(2)

Where:

L1 = the response prior to exposure to the radiation source L2 = the response in the presence of the radiation source

3.3.1.12 Shades of gray. The FWS-I shall present at least 256 gray levels. Levels 0, 1, ..., 254, 255 shall progress monotonically from the lowest available video (black) level to the highest available video (white) level. Upon application of a test pattern containing all Shades of Gray indicated in 3.6.17, an observer shall visually perceive each shade of gray as a different shade when viewed through the eyepiece of the FWS-I.

3.3.1.13 Display brightness. The FWS-I shall have variable display brightness to allow viewing in ambient illumination conditions from bright sunshine to total darkness without degrading system performance or inhibiting the operator's dark adapted vision. When viewed through the eyepiece, the display brightness level (with the display color of the thermal imagery) shall be adjustable from no greater than 0.05fL (minimum brightness setting / addressable gray-level 1) to at least 30fL (max brightness setting / addressable gray level 255). The measurement shall be performed by placing a calibrated photometer (with 5mm aperture mounted at the entrance of photometer lens) at the correct eye relief and on axis with the eyepiece measuring the center of the display through the eyepiece.

3.3.1.13.1 Display color. Display shall be monochrome (black/white or green/black).

3.3.1.14 (KPP) Battery. The FWS-I shall be operable using a commercially available battery. The primary battery shall be the L91 1.5 Volt “AA” Lithium. The training battery shall be the nickel metal hydride rechargeable battery (capacity >2500 mAh) or equivalent. The system shall allow for the use of alkaline batteries. The system shall be powered by no more than 3 batteries.

3.3.1.14.1 (KPP) Battery life. The FWS-I shall be fully operational over the battery life requirements specified in Table 3.3.1.14.1-1:

Table 3.3.1.14.1-1. Battery Life Requirements

3.3.1.14.2 (KPP) Low battery indicator (LBI). The FWS-I system display shall include low battery indicator for the primary system battery which shall be displayed when 20 (-15/+20) minutes of operational life remain. The indicator shall only be visible when activated and shall not be shown in the critical display area (Region 1 of Figure E.1 of Appendix E). The low battery indicator shall be optimized for the primary battery. The LBI shall consist of the words “LOW BATT”, “LOW BATTERY”, “LOW”, or “BATT”, or a pictorial representation of a battery.

3.3.1.14.3 Battery Voltage Indicator. The FWS-I system display shall include an indication of battery or external power voltage relative to the operational battery cutoff. Refer to Table 3.3.1.14.3-1 for a breakdown of graduations shown on the battery voltage indicator display with respect to temperature and battery life remaining. The battery voltage indicator shall be optimized for the primary battery. When a change in the indicator occurs, the new display shall blink 5 times, 1 time per second. Level 1 bottom threshold represents the voltage at which the sight ceases to function reliably.

Table 3.3.1.14.3-1. Battery Voltage Indicator

3.3.1.14.4 Battery removal. The battery shall be easily replaced without using tools, without removing the sight from the weapon, without affecting boresight and/or image shift /zeroing/sight alignment and with the use of one hand with gloves appropriate for the operational temperature range.

3.3.1.14.5 Battery safety concerning commercial batteries. If multiple batteries are used in series, the FWS-I shall have visible warning on or near the battery compartment of the system. The warning shall indicate avoidance of mixing battery types (i.e., use of Alkaline, Lithium, NiCad, etc. at the same time). The warning shall also state avoidance of mixing new batteries with used batteries.

3.3.1.14.6 Deleted.

3.3.1.15 Effect of sun.

3.3.1.15.1 Effect of sun in FOV. The FWS-I shall not exhibit permanent degradation or damage resulting from the effects of the sun in the FOV for solar angles of less than 20-degrees to the horizon when the sun is allowed to track across the FOV of a stationary FWS-I. Temporary latent images which last no more than 24 hours are permissible, provided they are capable of being adjusted out by the operator via user initiated NUC calibration (3.6.4). After 24 hours, if the latent image is still visible it is deemed permanent damage. When the FWS-I is turned off, the shutter shall be left in the closed position to protect the thermal sensor.

3.3.1.15.2 Effect of sun in relation to display. The FWS-I shall have provisions to protect the display from damage due to inadvertently being pointed in the direction of the sun.

3.3.1.16 Scene energy with focal plane array. When the FWS-I is not providing imagery, the shutter shall prevent scene energy to be incident on the focal plane array.

3.3.2 Intra-Soldier Wireless (ISW) Performance Characteristics. The FWS-I shall fully comply with all the requirements found in the following documents: ISW protocol specification, FWS-I ISW ICD, ISW SolNet Protocol, ISW SolNet Descriptor specification, and ISW Embedment Guide (A3309771A, A3309750A, A3309776-, A3309776-1-,A3309770A in 2.2.2) without damage (3.6.1) to any of the components in 3.2 or degradation of performance (3.6.2) over all environmental conditions (3.3.8), including weapons firing (Table 3.3.8.16.1-1).

(KPP)The RTA capability shall be achieved wirelessly (3.3.6.3). The FWS-I display shall be turned off automatically during RTA operation, but shall be turned on immediately by pressing the appropriate button combination on the FWS-I tethered remote (Table 3.3.4.5.1-1).

3.3.2.1 ISW Modes. Over the full operating temperature range of the FWS-I (3.3.8.2.) and the ISW ICD compliant headset, the ISW modes shall be available 130 milliseconds after the user toggles an ISW mode change. The ISW capability shall have the following operating modes:

3.3.2.1.1 Spatially Aligned.

3.3.2.1.1.1 Deleted

3.3.2.1.1.2 Presentation. Activation of these sub-modes occur via the remote keypad and is actuated as described in 3.3.4.4.1.

3.3.2.1.2 Full Weapon Sight Imagery with Weapon Sight Reticle. Full FWS-I imagery with weapon sight reticle shall be displayed in the ISW ICD headset.

3.3.2.1.2.1 Field-of-View. The FOV shall be the full FOV of the FWS-I (3.3.1.5).

3.3.2.1.3 Picture-in-Picture (PiP). Full FWS-I imagery with weapon sight reticle shall be displayed simultaneously with ISW ICD headset imagery. The FWS-I shall allow for ISW ICD headset thermal imagery with FWS-I imagery in PiP and FWS-I imagery with ISW ICD headset thermal imagery in PiP.

3.3.2.1.3.1.1 Field-of-View. The FOV shall be the full FOV of both the FWS-I and the ISW ICD headset.

3.3.2.2 RTA Image Latency. The latency of the RTA imagery for all RTA modes shall be less than or equal to 80 ms (with 30ms allotted to ISW ICD headset). The RTA latency begins when the energy is detected by the FWS-I thermal sensor and ends when the RTA image is viewed on the ISW ICD headset display.

3.3.2.3 Deleted

3.3.2.4 Deleted

3.3.2.4.1 RTA Indicator Definitions/Requirements.

3.3.2.4.1.1 FWS-I battery level/LBI. Indicates the relative battery power level of the FWS-I. When the FWS-I Low Battery Indicator (FWS-I PRF 3.3.1.14.2) is triggered, this indicator shall notify the user the FWS-I batteries should be replaced as soon as possible and shall take the place of the battery level indicator. This indicator shall be white text/symbology.

3.3.2.4.1.2 Deleted

3.3.2.4.1.3 Future Messaging Area. This area shall be used/reserved for future message sharing such as wireless range finder data, gunshot detection information, etc. This indicator shall be white text/symbology.

3.3.2.4.1.4 Zoom. When applicable, an indicator informing the user that the weapon sight imagery is zoomed shall be displayed in the ISW ICD headset Goggle. The indicator shall only be displayed during the time the imagery is zoomed. The indicator shall be white text/symbology.

3.3.2.5 Deleted

3.3.2.5 FWS-I/ISW ICD headset RTA Image Characteristics.

3.3.2.5.1 Deleted.

3.3.2.5.2 RTA Visual Image Quality. Spurious images from targets or symbology shall not detract from normal operation or degrade functionality. There shall be no discernible image persistence, pulsing, or vibration. There shall be no perceptible rotation of the scene. The RTA imagery shall not degrade the operator’s ability to observe, track, and/or fire at stationary or moving targets under all operational conditions. The RTA imagery shall not exhibit any visible level of flicker, flashing (3.6.18), image artifacts or intermittent operation under all operational conditions.

3.3.2.6 RTA Operational Readiness. Over the full operating temperature range of the FWS-I (3.3.8.2.), the RTA capability shall be available within 15 seconds after the user toggles the FWS-I and ISW ICD compliant headset power.

3.3.3 Weapon Sight Physical Characteristics. The FWS-I shall meet all requirements specified herein without damage (see 3.6.1) or degradation of performance (see 3.6.2) over all environmental and operational conditions, including weapon firing on interfacing weapons employed by soldiers (3.3.8).

3.3.3.1 (KPP) Weight. The maximum allowable FWS-I total system weight is 1.5 lbs. The specified weight limit includes the weight of the weapon sight (3.2.1.a) (loaded with batteries), the tethered remote (3.2.1.b), the objective lens cover (3.2.2.a), the mount assembly (3.2.2.b), and the eyecup (3.2.2.h). The maximum allowable weight of the FWS-I soft carrying case shall not exceed 1.0 lb. (453.6 grams).

3.3.3.2 Weapon/FWS-I accuracy. The FWS-I, when installed or removed from the host weapon, shall not degrade the inherent accuracy of the host weapon system. The FWS-I shall not be significantly affected by the operational characteristics of the host weapon. Momentary upsets due to firing or shading due to barrel heating are not considered significant. In automatic gain control, barrel heating shall not affect the automatic gain value applied in the critical display area (Region 1 of Figure E.1 of Appendix E).

3.3.3.3 Operating orientation. The FWS-I shall operate in any orientation without damage or degradation of performance.

3.3.3.4 Objective lens protection. An objective lens cover shall be provided to protect the primary objective lens from dirt, abrasion, or breakage. The objective lens cover shall be attached in a captive arrangement to allow the objective lens cover to be flipped out of the way during FWS-I usage, but remain securely attached to the system. The lens cover shall remain out of the way during weapon firing. The objective lens cover shall be a field replaceable item at the organizational (crew) maintenance level, shall not require any special tools to remove and replace, and boresight and/or image shift retention shall not be affected by replacing the lens cover. The objective lens cover shall not come into contact with the optical surface of the objective lens when closed due to lack of standoff or natural deformation of cover material under standard operating conditions, including the range of storage temperatures, and orientations, including upright, hand-held, mounted to weapon, or stored in soft case.

3.3.3.5 Carrying case. The FWS-I shall have a soft water resistant carrying case that keeps the FWS-I secure and protected. The case shall provide storage space for the FWS-I (with objective lens cover, eyecup, mount assembly), one M16A1/A2 mounting bracket (80063-A3170580), a spare set of batteries, DVO Coupling shroud, operator installed/removable spacer, operator’s manual, lens cleaning material, and quick reference card. The color of the carrying case shall be comparable to the Operational Camouflage Pattern (OCP) or solid colors TAN (499) or Coyote brown (498) unless otherwise specified by Government Agreement, Contract, or Purchase Order.

3.3.3.6 Transit/storage case. A transit/storage case or commercially acceptable container shall be provided which holds one FWS-I system in its carrying case, including all accessories listed in 3.3.3.5. The FWS-I, in its transit/storage case or commercially acceptable container, shall survive, without damage or performance degradation, normal commercial (i.e., tractor trailer, flatbed trailer, delivery truck, overnight delivery aircraft) and military methods of transportation (i.e., cargo aircraft/truck, helicopter).

3.3.3.7 Mechanical zero. The infrared line of sight corresponding to the center of the FWS-I display shall be parallel to the sight’s mounting surface to within 10% of the vertical NFOV with the reticle position indicator at zero/zero (in standalone mode only). After mechanical zero calibration, and with the reticle position indicator at zero/zero, the battlefield zero aim point of the reticle shall be aligned to the infrared line of sight as modified by the weapon/sight specific offsets indicated in Table 3.3.3.7-1 below, and in accordance with paragraph 3.3.3.13.

Table 3.3.3.7-1. Weapon/Sight Specific WFOV Offsets for 25 Meter Zeroing Range

1. Sight alignment of the M136 (AT4) and M141 BDM is not performed on 25m zeroing range.

2. Objective requirement

3.3.3.8 Weapon Boresight Retention/Image Shift.

3.3.3.8.1 (KPP) Weapon Boresight Retention. Defined as the ability to retain an angular relationship between the optical line of sight represented by the FWS-I reticle and the FWS-I mount interface (e.g., the MIL-STD-1913 rail). The FWS-I, once boresighted to a weapon, shall retain boresight. The FWS-I, when mated to any of the weapons specified in Table 3.3.3.8.1-1 shall retain boresight within the stated limits over all environmental conditions, weapons fire shock, temperature, temperature shock, vibration, shock, mount/dismount cycles, input voltage drift, power on/off cycles, change Field of View cycles, feed tray closures, or any compounded combination of these conditions, within the limits specified in the Tables.

TABLE 3.3.3.8.1-1. FWS-I Environmental Boresight

* The maximum angle between the weapon boresight and FWS-I reticle after alignment.

*** For the M203/M320, the boresight requirement is to the host weapon (M4/ M16).

3.3.3.8.2 Image Shift Retention. The FWS-I, when mated to any of the host weapons specified in Table 3.3.3.8.2-1 in conjunction with a DVO in a clip-on WFOV capacity, shall not have an image shift retention (3.6.27) greater than 2.0 MOA, over all environmental conditions, weapons fire shock, temperature, temperature shock, vibration, shock, mount/dismount cycles, input voltage drift, power on/off cycles, change Field of View cycles, feed tray closures, or any compounded combination of these conditions, within the limits specified in the table.

TABLE 3.3.3.8.2-1. FWS-I Environmental Image Shift

Weapon Sight

Bracket/Rail System Aimpoint Retention (# of rounds)

FWS-I

M4/16 series: 5.56mm Rifle, Carbine, and Modular Weapon Systems SDMR: Squad Designated Marksman Rifle NGSW-R/AR Next Generation Squad Weapon-Rifle and Automatic Rifle

5,000

TBD

** Pending development of M249 rail system to support in-line usage of the FWS-I with day view optic.

3.3.3.8.3 (KPP) Weapon Zero Repeatability. The FWS-I, when mated to any of the weapons specified in Table3.3.3.8.1-1, shall maintain zero within 0.25 mrad, over 10 mount/dismount cycles to the same rail position on the same weapon. With the FWS I mounted to the weapon, one mount/dismount cycle is defined as the dismount of the FWS-I from the rail and remounting on the same rail and weapon.

3.3.3.9 Eyepiece lens focus. The FWS-I shall have a fixed diopter setting of 0.00 (+0.04/‑0.06) diopters. The diopter settings shall not be changed by environmental conditions including weapon fire.

3.3.3.10 Proscribed area concerning M4/M16 series weapons. The FWS-I (standalone mode only) shall not interfere with the proscribed area defined in Figure 3.3.3.10-1. All controls on the FWS-I shall be accessible by the operator when mounted on the MIL-STD-1913 rail in standalone mode. All controls on the FWS-I shall be accessible by the operator when mounted on the forward rail when mounted in clip-on mode.

Figure 3.3.3.10-1 1 M4/M16 Series Proscribed Area (cross-hatched)

3.3.3.11 Proscribed area concerning Next Generation Squad Weapons –Fire control (NGSW-FC). The FWS-I shall not interfere with lines of sight needed for operation of the NGSW-FC. FWS-Is shall be limited to a height of 2.8 inches above the rail, and maximum width of 3.3 inches. Additionally the rail grabber/system shall extend no more than 0.361 inches below the rail.

3.3.3.12 Symbology burn-in. There shall be no residual visible symbology (3.6.24), to include the reticle (3.3.3.13), perceivable by the operator on the FWS-I display, when fully operational, under all display settings (3.3.1.14.1-5).

3.3.3.13 Reticle. The FWS-I shall have reticles compatible with each supported weapon. The reticle patterns shall be electronically generated in accordance with Appendix F, have boresighting capability requiring no special tools, and shall be selectable by the operator. The horizontal reticle line shall be horizontal within 5 degrees referenced to the mounting surface of the system. The vertical reticle line shall be perpendicular to the horizontal reticle line within 0.1 degrees. The reticle (with polarity adjustment) shall be visible at all display level, gain control, and scene polarity settings. The reticle selection and boresight shall be retained during battery exchange and when power is cycled off. The M16 reticle pattern information in Appendix F shall also be used for M16A4, M4A1, and M4A1 Carbine. The M136 reticle pattern information in Appendix F shall be used for the M136.

3.3.3.13.1 Reticle size. The FWS-I reticle line thickness shall be no greater than one IFOV. The reticle line thickness tolerance shall be no greater than 15%. Reticle size shall remain constant under all environmental conditions. For systems with E-zoom, reticle thickness in zoomed mode shall not exceed the thickness of the reticle in the display when not in zoomed mode.

3.3.3.13.2 Reticle travel. The FWS-I shall have a minimum reticle travel of 33 percent of the FOV both vertically and horizontally from mechanical zero (3.3.3.7), totaling 66 percent of the display from stop to stop.

3.3.3.13.3 Reticle stability. The FWS-I reticle adjustment increments shall remain uniform over the entire adjustment range. The reticle size, shape, and orientation shall remain stable over the entire adjustment range.

3.3.3.13.4 Reticle parallax. Parallax between a display image and the FWS-I reticle shall not exceed 50 percent of 1 increment of reticle adjustment, in any FOV, at every eyepoint in the exit pupil.

3.3.3.13.5 Reticle Contrast. The FWS-I reticle shall provide sufficient contrast at all display brightness settings to distinguish the reticle from the image observed through the FWS-I eyepiece

3.3.3.13.6 Reticle color. The FWS-I shall have a default reticle color opposite of the FWS-I polarity setting (black reticle in white-hot scenes and white reticle in black-hot scenes). The FWS-I shall include user selectable options for an all black or all white reticle regardless of polarity setting and a dynamic, scene-based reticle color option that automatically changes the reticle color to the opposite of the scene about the aimpoint.

3.3.3.13.7 Mil-scale reticle. The FWS-I shall provide a mil-scale reticle in each field of view. The mil-scale reticle shall be enabled via menu selection. The mil-scale reticle shall be centered and will not be allowed to adjust in WND or EL.

3.3.3.13.8 Reticle Aimpoint Centered NFOV. The NFOV of the FWS-I shall be centered about the center aimpoint of the reticle for all windage and elevation settings to ensure that all reticle aimpoints and features are displayed.

3.3.3.13.9 Reticle Alignment with DVO. The FWS-I shall provide a mode that allows for the alignment of the FWS-I reticle with the zeroed DVO aimpoint. When in this mode, the FWS-I display shall maintain the clip-on configuration alignment and any display dithering (if required) shall be disabled. Once aligned, these reticle settings shall be retained for use in the RTA and Standalone modes

3.3.3.14 Controls. The operator control functions in sections 3.3.3.14.1 through 3.3.3.14.15 shall be provided on the FWS-I. All controls to implement these control functions shall:

a. have consistent position and function as described in Technical Manual 11-588-343-10

b. have positive stops or indicate actuation on the display.

c. indicate function, direction and resulting action.

d. not allow accidental movement of the controls in all environmental conditions including weapon shock.

e. be adjustable using bare hands, MOPP-IV gloves and/or arctic mittens.

f. be easily adjusted by the 5th to 95th percentile of US Army personnel while in the firing position with the FWS-I mounted on all of the supported weapons.

g. not present a discernable delay (3.6.3) between actuation and completion of control adjustment unless otherwise stated.

3.3.3.14.1 Off/on brightness. Off/on and brightness control function(s) shall be provided to turn the FWS-I ON, OFF and to vary the peak brightness level (luminous intensity) of the display from the display minimum to maximum levels. The FWS-I shall require a positive control actuation by the user to turn the system ON and OFF. The brightness control function shall be provided with a symbol depicting a variable quantity from minimum to maximum brightness. The symbol can be provided near the control or in symbology on the display. The ON/OFF and brightness controls may be separate discrete controls.

If separate, the ON/OFF control shall provide means to identify as such. The ON/OFF and brightness controls, whether together or discreet, must be available during all modes of operation.

3.3.3.14.2 Contrast/gain. Contrast control function shall be variable and shall simultaneously adjust the gain of all signal channels. An automatic gain setting control function shall be included. A manual gain and level control function shall be provided which, when activated, would override the automatic gain function and provide manual gain and level control. The control shall be labeled and shall be provided with a symbol depicting a variable quantity. The automatic setting position shall be labeled. This control must be available during all modes of operation.