Simulation of the infrared signature of exo-atmosphere micro-motion object

As an important passive sensing technology, infrared sensor has been used in satellite remote sensing systems to discriminate exo-atmosphere targets. At a long range, even relatively large objects are represented as single pixels on the IR image. The infrared signature, i.e., the time sequence of the target point's gray level serves as potential discriminants and has been used in many systems to classify the objects. Studying the generative process of the infrared signature is the premise of this research. In this paper, finite element analysis is used to simulate the infrared signature of exo-atmosphere micro-motion object. Modeling the dynamic of surface temperature field of the targets is a critical step. The main contribution of this paper is to analyze the influence of the micro-motion to the modeling of temperature field. Micro-motion is an important characteristic of the ballistic target. The way of motion causes the radiation received by the surface element changes dramatically, which may affect the simulation process. However, to the best of our knowledge, this problem has not been addressed in other papers. Two temperature field modeling techniques, i.e., the explicit and hidden schematic, are assessed at different sampling time steps. The results show that the explicit method is easy to cause oscillating for the micro-motion object. Although the hidden method is able to avoid the oscillating problem, sufficient small sampling time step is still needed to generated stable surface temperature field. The simulated temperature field dynamic shows that the temperatures in the field approach to be the same and do not change much in a short time period. After the temperature field is generated, micro-motion target's infrared signature is also generated.