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Fascinating technology! Possibly well-suited to finding transient
"stars" (meaning previously unidentified asteroids) given an appropriate
observation location, such as a small satellite.
--rtw

Frank Reed wrote:
>  From the press release:
> "Trex Enterprises’ is developing a multi-aperture stellar tracker able to 
detect stars during daylight. Trex has developed proprietary automated star 
pattern recognition algorithms. Working with the U.S. Navy, Trex has 
developed and demonstrated the Daytime Stellar Imager, an infrared sensor 
capable of seeing stars in daylight and at night, thus being able to create 
an alternative navigating system. Such system could be used on naval surface 
vessels and aircraft, independent of global positioning systems (GPS) or 
Inertial Guidance Systems (INS). The system can deliver precision azimuth 
reference, for precision pointing at sea and on battlefield. Trex Enterprises 
developed the automated the star detection capability and pattern recognition 
algorithm. The system can detect a 6.3 magnitude star at daytime, at sea 
level."
>
> I'm not surprised they can detect first and second magnitude stars. I'm 
impressed that they can get as deep as magnitude 6.3. Given that, the 
"multi-apertures" can be presumably be pointed in fixed directions relative 
to each other. For example, you could have one pointing "up" and three others 
evenly spaced in azimuth angled sixty degrees away from the "up" sensor. Each 
could detect dozens of stars and then it's just pattern-matching to identify 
the stars and convert that to orientation data. There's no clue yet in any of 
the articles how this particular system establishes a vertical. Perhaps it's 
semi-inertial, or maybe it's by refraction (which would require a few more 
sensors aimed at low altitudes).
>
> By the way, the astro-compass capability of a system like this is genuinely 
unique. Orientation is one problem that astronomy solves far better than any 
other system.
>
> A cloudy day is still a show-stopper!
>
> -FER

   

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