Long-term performance evaluation of a NIR gated viewing sensor in scattering environments

Jendrik Schmidt; Matthias Mischung; Enno Peters; Susanne Wollgarten; Maurice Stephan

doi:10.1117/12.2599892

12 September 2021 Long-term performance evaluation of a NIR gated viewing sensor in scattering environments

Jendrik Schmidt, Matthias Mischung, Enno Peters, Susanne Wollgarten, Maurice Stephan

Proceedings Volume 11866, Electro-Optical and Infrared Systems: Technology and Applications XVIII and Electro-Optical Remote Sensing XV; 118660V (2021) https://doi.org/10.1117/12.2599892
Event: SPIE Security + Defence, 2021, Online Only

Abstract

Maritime search and rescue operations (SAR) are highly affected by harsh environmental conditions and darkness (night time operation). Especially at low visibility and high humidity scenarios like fog, mist or sea spray, gated-viewing offers an active-imaging solution to effectively suppress atmospheric back-scatter and enhance target contrast. The presented TRAGVIS gated-viewing system is designed to fill the needs in SAR operations: at least 185 m detection range at a minimum FOV of 7°x6° and operates in the NIR at 804 nm emission wavelength, combining a high repetition rate VCSEL illuminator with an accumulation mode CMOS camera. The performance of the demonstrator in a wide range of different visibility fog events and different sets of system parameters has been evaluated by analysing the target signal, contrast and signal to noise ratio SNR as a function of the optical depth OD, which was measured by an atmospheric visibility sensor. As the back-scattered signal (suppressed by the camera shutter) overcomes the target signal of a 41% reflectivity target at OD > 4, it was found, together with a low target signal, to be the major reason for the drop of contrast after a vision enhancement up to OD ≈ 3. A limitation of the system to approximately OD = 5.3 is estimated, as the image shows a decent contrast of 10%, but at an SNR of only ∼ 2.2. The highest potential for improvements was found in an optimised placement of the illuminator with respect to the receiver and scene geometry.

Conference Presentation

Citation Download Citation

Jendrik Schmidt, Matthias Mischung, Enno Peters, Susanne Wollgarten, and Maurice Stephan "Long-term performance evaluation of a NIR gated viewing sensor in scattering environments", Proc. SPIE 11866, Electro-Optical and Infrared Systems: Technology and Applications XVIII and Electro-Optical Remote Sensing XV, 118660V (12 September 2021); https://doi.org/10.1117/12.2599892

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available