## Abstract

Thermal/Infrared (TIR) sensors are being considered for Guidance, Navigation and Control (GNC) systems, in addition to the existing roster of visible light spectrum (VIS) sensors. The real-time generation of synthetic data used to supplement and extend existing datasets used in closed-loop testing should also be extended to the TIR spectral range. For spacecraft this has previously been limited to ‘stateless’ methods in rasterisation based systems, i.e. with no consideration of TIR effects that occur over time, such as thermal conduction and thermal capacitance; or to computationally expensive methods in more traditional engineering software, such as Monte-Carlo based

ray tracing and Finite Element Analysis (FEA). This paper reports on the progress of a technique being developed for synthetic TIR image generation in rasterisation based systems: a ‘capacitance model’ that involves the creation of a Thermal Mathematical Model (TMM), to keep track of the temperature of each node, and the assignment of thermal properties to each node. This allows the examinination of the time-based thermal-infrared (TIR) effect of thermal inertia (also known as thermal lag), a result of thermal mass that affects the temperature change of an object as the input and/or output energy changes i.e. during transient stages of heat transfer. An OpenGL prototype was developed, aiming to recreate a set of thermal inertia functions to show how simulation of this effect can improve the accuracy of real-time generated

images, in particular during the simulation of important transitional phases of spacecraft orbits, e.g. the entry or exit of eclipse. Mathematical functions can be used to effectively simulate time-based thermal inertia as an extension of previously used standard thermal equations, and in future these functions could be combined to simulate complex thermal profiles, e.g. those of a spacecraft in planetary orbit.

ray tracing and Finite Element Analysis (FEA). This paper reports on the progress of a technique being developed for synthetic TIR image generation in rasterisation based systems: a ‘capacitance model’ that involves the creation of a Thermal Mathematical Model (TMM), to keep track of the temperature of each node, and the assignment of thermal properties to each node. This allows the examinination of the time-based thermal-infrared (TIR) effect of thermal inertia (also known as thermal lag), a result of thermal mass that affects the temperature change of an object as the input and/or output energy changes i.e. during transient stages of heat transfer. An OpenGL prototype was developed, aiming to recreate a set of thermal inertia functions to show how simulation of this effect can improve the accuracy of real-time generated

images, in particular during the simulation of important transitional phases of spacecraft orbits, e.g. the entry or exit of eclipse. Mathematical functions can be used to effectively simulate time-based thermal inertia as an extension of previously used standard thermal equations, and in future these functions could be combined to simulate complex thermal profiles, e.g. those of a spacecraft in planetary orbit.

Original language | English |
---|---|

Number of pages | 13 |

Publication status | Published - 2023 |

Event | 12th International Conference on Guidance, Navigation & Control Systems (GNC) - Sopot, Poland Duration: 12 Jun 2023 → 16 Jun 2023 Conference number: 12 https://atpi.eventsair.com/gnc2023/ |

### Conference

Conference | 12th International Conference on Guidance, Navigation & Control Systems (GNC) |
---|---|

Country/Territory | Poland |

City | Sopot |

Period | 12/06/23 → 16/06/23 |

Internet address |