http://gpsworld.com/dual-frequency-gnss-smartphone-hits-the-market/
What impact will this have on GPS approaches in due course?
Dual frequency from a smart phone will have no impact, but the technology will enable procedures with vertical guidance equivalent to SBAS outside an SBAS service volume.
Presumably that phone supports Navstar (the original US GPS system) anyway, plus Galileo, and it reads like it is on Galileo it supports both frequencies. But would anyone make a chip which does just that?
No wonder that phone isn’t from Samsung, because they like to play games to collect wifi data
But it’s strange why one would want this in a phone, especially one without any special features (like a really good camera).
This dual frequency GPS stuff seems to have passed everyone by
It is perhaps as interesting to the main players (Garmin etc) as Galileo and Glonass of which neither is AFAIK supported.
But offering WAAS accuracy without WAAS satellite reception must be a huge advantage.
Peter wrote:
But offering WAAS accuracy without WAAS satellite reception must be a huge advantage.
Perhaps if you live in Eastern Romania, Northern Finland or the Canaries. But doesn’t it just allow most of us, possibly, to do tomorrow what we already do today?
Sure, it is a future thing.
But it would remove the need for the WAAS and EGNOS ground monitoring stations and the geostationary satellites, the massive cost of those and the various points of failure. Transmitting the same signals from every GPS satellite is a much better solution.
OK. How does multi constellation correct for ionospheric errors?
Maybe @NCyankee knows more but I vaguely recall reading something about the errors being different for the different carrier frequencies and this enables a large degree of error cancellation. It also provides a better resistance to jamming because you have more uncorrelated signal to correlate, so to speak.
Of course, you have been able to buy the Garmin GLO for years.
Receiving two constellations is not the same thing, AIUI. I was thinking of receiving L1 and L2 from any particular satellite concurrently.
I had a Thuraya + L1 + L2 antenna on my plane. It was never used for GPS because there is no civilian L2 GPS receiver and later I replaced it with one which does Iridium, Thuraya and L1 and that one feeds the ADL150 nicely.
Found a pic:
The abandoned project was written up here.
Anyway, the point is that receiving and correlating L1 with L2 can be used to cancel out most of the atmospheric error because the frequencies are sufficiently different. Whether any avionics will appear in any of our lifetimes is another matter…