Night vision goggles

Night vision goggles

Author: United States. Congress. House. Committee on Armed Services. Subcommittee on Investigations

Publisher:

Published: 1989

Total Pages: 128

ISBN-13:

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Visual Acuity and Stereopsis with Night Vision Goggles

Visual Acuity and Stereopsis with Night Vision Goggles

Author:

Publisher:

Published: 1989

Total Pages: 30

ISBN-13:

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Measurements of visual performance (stereopsis and visual resolution) were acquired to compare results achieved using unaided monocular and binocular viewing, monocular and binocular viewing with the AN/PVS-5A night vision goggles, and models A and B of the AN/PVS-7 biocular night vision goggles. All of the goggles were equipped with 2nd generation tubes. Using a modified Howard- Dolman apparatus to assess stereopsis, all of the goggle-assisted thresholds were very much larger than stereoscopic thresholds achieved with unaided binocular vision. Statistical analysis of the results indicated that stereopsis through night vision goggles, regardless of the model or viewing condition, is essentially eliminated and equivalent to the threshold obtained with unaided monocular viewing. In comparison, spatial resolution capability with all of the goggle systems is superior to performance with unaided vision. In agreement with previously published data, visual acuity with the goggles is approximately 20/ 50, but only for high contrast targets and simulated full moon ambient light levels. As light levels decrease to quarter moon conditions or target contrasts are reduced to more realistic values, visual spatial resolution with the goggles is much poorer. For infantry use, any differences in visual performance between monocular, biocular, and binocular designs probably are not operationally meaningful.


Transmissivity and Night Vision Goggle Compatibility Data for Select Aircraft Transparencies

Transmissivity and Night Vision Goggle Compatibility Data for Select Aircraft Transparencies

Author:

Publisher:

Published: 2003

Total Pages: 376

ISBN-13:

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This document is a compilation of spectral transmissivity data measured from numerous aircraft transparencies. The spectral transmissivity of each part was measured from wavelengths of 450 nm through 950 nm. Some parts were also measured at several different angles relative to the optical axis of the spectroradiometric instrument. The measurements yielded both visible light and near infrared (NIR) spectra. The NIR data were used to calculate night vision goggle-weighted transmissivity (TNVG) values (Pinkus and Task, 1997). TNVG is a measure of a transparency's compatibility when it is used in conjunction with night vision goggles (NVGs). NVGs utilize the NIR portion (600 nm through 950 nm) of the night sky ambient illumination. Generally speaking, the higher the TNVG coefficient, the higher the NVG visual performance (Pinkus & Task, 1998a; Pinkus & Task, 1997).


Experimental Flight Testing of Night Vision Imaging Systems in Military Fighter Aircraft

Experimental Flight Testing of Night Vision Imaging Systems in Military Fighter Aircraft

Author: Roberto Sabatini

Publisher:

Published: 2014

Total Pages: 17

ISBN-13:

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This paper describes the research and experimental flight test activities conducted by the Italian Air Force Official Test Centre (RSV), in collaboration with Alenia Aermacchi and Cranfield University, in order to confer night vision imaging systems (NVIS) capability to the Italian TORNADO Interdiction and Strike and Electronic Combat and Reconnaissance aircraft.The activities included design, development, test, and evaluation activities, including night vision goggle (NVG) integration, cockpit instruments, and external lighting modifications, as well as various ground test sessions and a total of 18 flight test sorties.RSV and Litton Precision Products were responsible for coordinating and conducting the installation of the internal and external lights.Particularly, an iterative process was established allowing in-site rapid correction of the major deficiencies encountered during the ground and flight test sessions.Both single-ship (day/night) and formation (night) flights were performed, with testing activities shared among the test crews involved, allowing for a redundant examination of the various test items by all participants.An innovative test matrix was developed and implemented by RSV for assessing the operational suitability and effectiveness of the various modifications implemented.Also important was the definition of test criteria for Pilot and Weapon Systems Officer workload assessment during the accomplishment of various operational tasks during NVG missions.Furthermore, the specific technical and operational elements required for evaluating the modified helmets were identified, allowing an exhaustive comparative evaluation of the two proposed solutions (i.e., HGU-55P and HGU-55G modified helmets) The initial compatibility problems encountered were progressively mitigated by incorporating modifications in both front and rear cockpits at various stages of the test campaign.This process allowed considerable enhancement of the TORNADO NVIS configuration, giving good medium- to high-level NVG operational capability to the aircraft.Further developments also include the internal/external lighting for the Italian TORNADO "Mid-Life Update" and other programs such as AMX aircraft internal/external light modification/testing and the activities addressing low-altitude NVG operations with fast jets (e.g., TORNADO, AMX, MB-339CD), with a major issue being the safe ejection of aircrew with NVG and NVG modified helmets.Two options have been identified for solving this problem, namely, the modification of the current Gentex HGU-55 helmets and the design of a new helmet incorporating a reliable NVG connection/disconnection device (i.e., a mechanical system fully integrated in the helmet frame) with embedded automatic disconnection capability in case of ejection.Other relevant issues to be accounted for in these new developments are the helmet dimensions and weight, the NVG usable field of view as a function of eye-relief distance, and the helmet's center of gravity (moment arms) with and without NVG (effect on aircrew fatigue during training and real operational missions).