Does someone already use a dual frequency smartphone ?
Might also be worth a look at using an SDR/gnuradio. Seems to need a reasonable SDR RF front end though, but have seen some discussion using cheap USB dongles…
I already use a dual-frequency receiver (u-blox F9P) with the centipede RTK network.
For HAS, 20 cm accuracy is the convergence target in less than 300 seconds.
The target seems to be with Galileo only and float convergence algorithm. With GPS+Galileo (without iono correction, not available in HAS Phase 1) and optimized algorithm, one may go down to 3 cm (horizontal) in about 2 mn.
It’s surprisingly difficult to get good quality GPS devices. Most of them don’t support the full accuracy of the GPS/Gallileo services available.
You end up having to spend hundreds on dedicated GPS hardware that is impractical to use.
Around 2000, we paid hundreds of euros/dollars for an outdoor GPS like Magellan Meridian for myself. Even in 2015, I bough my Etrex 30 for 200 €.
It costed my about 400 € to build my ublox F9P RTK datalogger (incl. antenna) following this project:
Dear @Eric_S ,
Thank you for your link to what looks like a thorough guide to assembling and getting to work an RTK logger;
having read it came to realise such a project beyond my abilities in the field of electronics - which is valuable!! - although unfortunately not progress beyond what is offered by the currently used Garmin eTrex 10 - which turns out to produce more accurate track than the Oregon 700.
Met vriendelijke groet, (Dutch for ‘with friendly greeting’)
Dear @Eric_S ,
Thank you for posting/ reminding that the very high ‘cm’ accuracy of Galileo and Galileo+GPS will only be achieved after perhaps two to five minutes; inserting the graphs gives some indication of increasing accuracy in function of (a longer) time spent measuring : measure one point for minutes -rather than seconds when taking a still photo- is unlikely, especially when travelling at any practical speed, hence ought to entertain lower accuracy expectations.
Met vriendelijke groet,