Thermal sensor acquisition range estimation

FFI-Report 2021

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Report number

21/00388

ISBN

978-82-464-3329-5

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12.9 MB

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Steinar Børve
There is a large number of factors which may influence the performance of thermal surveillance systems used in any given scenario. Some of the parameters needed for making an accurate performance prediction might be known, but many more are typically unknown or must be loosely guessed based on past experiences and information about similar systems and comparable situations. It is hardly realistic that operators will have access to a comprehensive list of parameters nor the numerical tools required to perform accurate predictions of the effective detection range during real-world operations. Simpler range estimation methods might be needed and rough guesses of system and environmental parameters might be necessary in order to get a reasonably good sense of the effective range of thermal sensors in operational settings. This report gives an introduction to the topic of thermal acquisition range estimation. It describes two common methods for performing calculations of this kind. The first method is formulated by a very simple equation but only considers target size and the most basic sensor properties. The second method, as formulated in STANAG 4347, is originally a non-linear equation which is commonly solved geometrically. This makes the method less suited for quick and automated estimation. Therefore, this report proposes a new, parametric second-order algorithm based on the STANAG 4347 method, where range can be estimated with model uncertainties easily being taken into account. To illustrate the use of the new algorithm, this report provides numerical examples relevant to the Norwegian Armed Forces. We look at 8 different thermal camera setups, ranging from low-weight binoculars to relatively large, vehicle-mounted systems. Since the second method takes into account atmospheric attenuation, a separate model for estimating the extinction coefficient for different climatic conditions has also been developed. The model is described in some detail. In addition, extensive tables are provided which list the extension coefficient calculated for a wide range of different weather and climate scenarios. In practical use, the idea is that an operator will have access to the tables rather than the full atmospheric model.

About publication

Report number

21/00388

ISBN

978-82-464-3329-5

Format

PDF-document

Size

12.9 MB

Download publication

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