Taka Kamiya and Forrest Christian both asked recently about the alternative satellite PNT system using the Iridium satellites. That system was developed by my company, Satelles. It has been commercially available for more than a year now.
The biggest advantage is that our signal is at least 30 dB stronger than GNSS signals (the exact numbers depend on whether you're talking to engineering or marketing :). You can easily get a usable signal in deep jungle, or a data center in the middle of a building's basement, or even inside a locked shipping container. The stronger signal is correspondingly more difficult to jam or spoof than GNSS, and our signal has anti-spoofing features as well. The biggest disadvantage is that it is not quite as accurate as GPS, because there are fewer satellites in view at any given time. I don't want to quote exact timing numbers here, because they depend a lot on system integration details, but you can easily steer an OCXO within a few hundred nanoseconds of USNO time. With a rubidium, you can do considerably better. If you want to know more, our website is www.satellesinc.com. (If this message has been too commercial, I apologize in advance. The boundary between information and salesmanship is not always sharp.) Cheers! --Stu _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
