Temporal extension of phase screen sequences using proper orthogonal decomposition

Markus Henriksson; Lars Sjöqvist; Jonas Tidström

doi:10.1117/12.2241036

21 October 2016 Temporal extension of phase screen sequences using proper orthogonal decomposition

Markus Henriksson, Lars Sjöqvist, Jonas Tidström

Proceedings Volume 9989, Technologies for Optical Countermeasures XIII; 99890H (2016) https://doi.org/10.1117/12.2241036
Event: SPIE Security + Defence, 2016, Edinburgh, United Kingdom

Abstract

For performance modelling of optical countermeasure systems simulation of turbulence effects is necessary. Physical optics numerical beam propagation using phase screens is an established method in this respect. In some cases a short sequence of temporally resolved phase screens is available from Computational Fluid Dynamics (CFD) simulations or from wavefront sensor measurements. It is, however, seldom possible to provide enough sequences and sufficient sequence length for Monte Carlo simulations of system performance utilizing these methods. Therefore, we have investigated the possibility to generate an arbitrary number of longer temporal sequences of phase screens with the same statistical properties for simulation of turbulence, based on an available short phase screen sequence. The method apply Proper Orthogonal Decomposition (POD), a method used to generate orthogonal modes from a dataset. For discretely sampled sequences the Singular Value Decomposition (SVD) algorithm is suitable to extract the set of POD modes. This scheme provides a separate temporal sequence of coefficients for each spatial mode. The next step is to generate new, longer temporal sequences of coefficients with the same statistical properties as those extracted by the SVD algorithm. Finally a new sequence of phase screens is generated by adding all spatial modes. The method is illustrated using data from CFD calculations of a down-scaled jet engine plume. The method is especially suitable for very strong localized turbulence as in aero optics and engine exhaust plumes, but may be useful also for extended turbulence. The use to generate Power-In-Bucket (PIB) sequences for evaluation of turbulence distortion effects is demonstrated. PIB is an important quantity when evaluating e.g. the performance of directed infrared countermeasure (DIRCM) systems.

Citation Download Citation

Markus Henriksson, Lars Sjöqvist, and Jonas Tidström "Temporal extension of phase screen sequences using proper orthogonal decomposition", Proc. SPIE 9989, Technologies for Optical Countermeasures XIII, 99890H (21 October 2016); https://doi.org/10.1117/12.2241036

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