Inexpensive GPS modules supporting raw measurement?

[abhishekkumar1902]

I am working on an application where I want to implement RTK (Real Time Kinematics) and/or DGPS (Differential GPS) which needs GPS modules which supports raw measurements for example the NEO-7P module from ublox. NEO-7P is a pretty expensive module costing around 70$. I just wanted to know if there are any inexpensive GPS modules available in the market which supports raw measurement?

[David Hess]

I did not know that any of the Ublox GPS receivers or anybody elses supported raw measurements.  Huh, it even says it supports raw data in the specifications.

Raw measurement output is supported for GPS signals at an update rate of up to 10 Hz. The UBX-RXM-RAW message includes carrier phase with half-cycle ambiguity resolved, code phase and Doppler measurements, that can be used in external applications that offer precision positioning, real-time kinematics (RTK) and attitude sensing. The UBX-RXM-SFRB message contains sub-frame data for GPS and SBAS satellites.

$70 seems like a deal for that.

[Gyro]

The LEA-6T also supports Raw data output (5Hz on the LEA-6T-0 and 2Hz on the LEA-6T-1).

I think I remember reports of some sort of bug in it though or workaround needed, possibly resulting in it appearing in a bunch of cheap ebay GPS (+ Compass) units for drones.

e.g. https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR0.TRC0.H0.Xlea-6T.TRS0&_nkw=lea-6T&_sacat=0

Probably worth some further research on the subject.

[edavid]

There is also a $50 NavSpark module:

http://navspark.mybigcommerce.com/ns-hp-rtk-capable-gps-gnss-receiver/