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GPS receivers which are suitable for use with Kinematic
An ideal receiver has the following properties.
- Provides low noise pseudorange measurements
- Provides full wave carrier phase information
- Has a stable internal clock with minimal drift
- Provides ephemerides
- Tracks well under less than ideal conditions
- Costs less than $200.
No one receiver meets all these criteria, so there will always be some
compromise when selecting a receiver. I'll mention receivers which work (or
could potentially work) with Kinematic. Please let me know if you have
corrections, additions, or would like to interface a new unit. The units with a "*" currently
interface to the Kinematic software.
OEM Receiver Boards (1-2 cm)
These GPS receivers are intended to be incorporated into other devices.
You can't buy them at the local store, but you can order them online from
the manufacturer or a special distributor. They are raw circuit boards. You
have to provide power, a USB or RS232 interface, and a box. You might have
to solder cables. (Note that Kinematic can currently only do 20-50cm positions.)
- *Thales AC12.
- *u-blox Antaris and *Antaris LEA-4T. (The "T" is important.)
- Furuno GT8032.
- ITrax 03
- Superstar II with the right options.
- Allstar, a discontinued version of Superstar
- Motorola Oncore, an older receiver.
Some of these receivers give 5 or 10 Hz updates, which would be very
useful for dynamic situations (say monitoring a race car or guiding a model
aircraft).
"Raw" Consumer Grade Receivers (20-50cm)
Consumer grade receivers are widely available, often at a very low price.
Most are complete and ready-to-use, although some are boards intended for
the consumer market. While these receivers provide phase measurements, the
measurements are generally not good enough to calculate a "fixed" solution.
Still, they can be coaxed into providing good "float" positions at a very
low cost.
- *Sirf II. (Note: Sirf III does not provide carrier phase.)
- *Garmin GPS18usb.
- Other Garmin units. There is a free Garmin-->Rinex converter
available.
- *Trimble Lassen IQ. Does not provide phase, but the Doppler
measurement can be integrated to provide "phase-like" information.
(to be verified)
Other Notable Receivers
The Sirf III provides raw pseudoranges and has excellent tracking, but
it is missing carrier phase information. It may be useful for static
positions in poor conditions where other receivers are unable to track
at all.
"DGPS" Receivers (50cm -3m) (Currently, not part of
Kinematic)
Many consumer and OEM receivers support RTCM 104 DGPS corrections. When
connected to a local reference station, these receivers can provide submeter positions
in real-time. While DGPS is not as precise as double differencing, it
is a convenient way to get "pretty good positions", especially for GIS
mapping. Note that you need some means of transmitting corrections to your
receiver, either a radio link or a wireless internet connection. (Check out
the ntrip open source software.)
Allstar
The Allstar deserves special DGPS mention. The Allstar was the only low
cost receiver which generated RTCM 104 DGPS corrections. Allstars have been
discontinued, but if you have one, it can be used as a cheap, standalone
DGPS reference station.
Kinematic may eventually include the ability to generate DGPS
corrections. If you know of an existing opensource or low-cost package, let
me know and I'll add a link to it.
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