Thermal sensor acquisition range estimation
FFI-Report
2021
About the publication
Report number
21/00388
ISBN
978-82-464-3329-5
Format
PDF-document
Size
12.9 MB
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 the publication
Report number
21/00388
ISBN
978-82-464-3329-5
Format
PDF-document
Size
12.9 MB