How sun sensors work
Sun sensors are navigation instruments that are used in space to establish the direction and position of the sun in relation with the satellite or spacecraft. In the aerospace sector they are mainly used to monitor attitude, to guide the orientation of solar panels and other functions.
These devices are used to determine attitude in space, providing data about the orientation of the satellite in relation with the solar vector, which is the angle at which the sun rays reach the satellite or spacecraft.
Sun sensors work by allowing light to enter through a small window (which may be of varying shapes and sizes) in the top of the sensor device, which consists of several or many photosensitive units.
These photosensitive units work by using the photoelectric effect: they convert the photons that reach them into electrons, and thereby into electric currents that can be made into a signal that sends information.
Light enters the window and projects an image onto the base of the device. At this point, the photosensitive cells measure the amount of light and it can be used to calculate the angle of incidence.
There are several special types of sun sensors, and each project should use the one which is best suited to the characteristics and requirements of the satellite. At Solar MEMS we offer personalized engineering services which can determine the needs of each mission and adapt to them accordingly, creating customized space software and hardware systems.
The main categories of sun sensors that are used in the aerospace market are Fine analogue sun sensors, Coarse analogue sun sensors and Digital sun sensors. Let’s take a closer look at how each of these works.