Intertech-Pira published an interview with Guy Meynants, VP R&D at CMOSIS and speaker at the upcoming ISE 2011 conference, talks about digital Sun-sensor on-a-chip for space navigation.
Guy says: "A sun sensor is used as a part of the attitude and orbit control systems in a satellite or a spacecraft. It searches for the location of the sun in a section of the sky, extracts the centroid of the sun to sub-pixel resolution and then tracks the sun position. This information gives a partial solution to the attitude of the spacecraft. Common sun sensors rely on separate image sensors and an electronic processing unit to extract the sun information. That is rather bulky and complex. We have integrated all of this in a single sensor. This allows a much more compact system. In the presentation, the architecture of that chip is presented and its key performance data is given."
well ... what is the news?
ReplyDeleteMaybe I'm naive, what is the main difficulty in such sensor? The Sun is the brightest celest body and the centroid computation is not difficult.
ReplyDeletemy guess is radiation tolerant design? especially with a system on chip design
ReplyDeleteI don't really see any added value in this device.
ReplyDeleteFillfactory (later Cypress, and now recently acquired by ON Semiconductor) already has radiation tolerant space qualified star tracking image sensor device in the market.
Unless the actual performance of the "sun sensor" is overwhelming, we will not see such a device in space. At least not in the first decade.
What are the critical performance requirements in such device? Position precision?
ReplyDeleteWeight, power dissipation, size to name a few. For this type of attitude sensor, there are numerous other parameters to consider than precision. Sun sensors are coarse attitude sensors, compared to star trackers.
ReplyDeleteThere exist also high-accuracy sun sensors. These tend to weight around 1kg. The CMOSIS sensor is a complete system on chip, and highly accurate too. It enables instruments of a couple of tens of grammes. Next to consumer market sensors that doesn't seem much, but for space this really is a big deal.
ReplyDeleteAnd what is the next step? A star tracker on a chip?