# Light radiation pressure upon an optically orthotropic surface

## TL;DR

This paper develops a model to calculate light radiation pressure on anisotropic, orthotropic surfaces, such as wrinkled solar sails, using modified Maxwell's equations and Bayesian analysis to improve accuracy over isotropic models.

## Contribution

It introduces an orthotropic model for optical parameters and derives force equations considering emission, absorption, and reflection, enhancing modeling of complex surfaces.

## Key findings

- Orthotropic model can outperform isotropic models in certain cases.
- Bayesian analysis confirms the model's improved accuracy for wrinkled surfaces.
- The model is applicable to flat solar sails with wrinkles.

## Abstract

In this paper, we discuss the problem of determination of light radiation pressure force upon an anisotropic surface. The optical parameters of such a surface are considered to have major and minor axes, so the model is called an orthotropic model. We derive the equations for force components from emission, absorption, and reflection, utilizing a modified Maxwell's specular-diffuse model. The proposed model can be used to model a flat solar sail with wrinkles. By performing Bayesian analysis for example of a wrinkled surface, we show that there are cases in which an orthotropic model of the optical parameters of a surface may be more accurate than an isotropic model.