[FOSS-GPS] High accuracy positioning with low cost GPS devices:a FOSS project

[Michael Tandy]

> I have heard the SIRF-II chipset also offered this raw data; but those
> have largely been replaced with SIRF-III which doesn't offer the right
> raw data - Sparkfun does have a few SIRF-II modules in stock though; I
> don't know if sparkfun have a source for new SIRF-II modules after
> those are out of stock.

Just to follow up on this for anyone who is interested, it seems the
SiRF II is still available, in the form of the SiRF GSC2x. This is
used in both these SparkFun gps modules:
http://www.sparkfun.com/commerce/product_info.php?products_id=576
http://www.sparkfun.com/commerce/product_info.php?products_id=577

Googling "sirf gsc2" found me the "GlobalSat BT 328" bluetooth
receiver which I was able to buy for about $40, and which (with a bit
of care) outputs carrier phase information using SiRF binary message
28.

Unfortunately it's bluetooth only, and it's less sensitive than the
LEA-4T, but for the price you can't really complain.