Hi The Iridium frequencies are even further “up band” than the Glonass signals. None of the “GPS” antennas that I have tried work very well on Glonass. I doubt they would do well at all trying to get Iridium.
Bob > On May 19, 2015, at 1:57 AM, David I. Emery <[email protected]> wrote: > > On Mon, May 18, 2015 at 09:52:03PM -0700, Jim Lux wrote: > >> Why iridium? Why not Sirius or XM or DBS. Unless you want something >> world wide, as opposed to "populated areas served by broadcast radio and >> TV" > > Well it seems to me I remember Iridium is time domain duplex > around 1610 MHz or thereabouts... which isn't too far from the L1 > civilian GPS at 1575.42 and quite possibly inside the bandwidth of > some civilian L1 LNAs and antennas. > > Sirius XM is not that close at 2320-2345 Mhz. > > And inside its spot beam the Iridium signal is quite a bit more > powerful and coming at one from constantly changing angles... whilst > the Sirius XM birds are either geosync or in Molninya orbits and don't > move much over short intervals - as does an Iridium signal. > > And of course (for the military especially) it IS worldwide and > not just restricted to NA (where such an anti-jam capability is less > useful at least at the moment). Something that works world wide > is of course what the military folks need. > > And I suspect timing can be derived from the satellites TDD > and message timing pretty easily if that is accurately synced to some > reference... > > Others more familiar with the details may comment here... > > -- > Dave Emery N1PRE/AE, [email protected] DIE Consulting, Weston, Mass > 02493 > "An empty zombie mind with a forlorn barely readable weatherbeaten > 'For Rent' sign still vainly flapping outside on the weed encrusted pole - in > celebration of what could have been, but wasn't and is not to be now either." > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
