[Loadstone] GPS receivers tested

Rob Melchers rob at loadstone-gps.com
Sun Dec 28 10:42:50 GMT 2008


The Breadcrumb generator on the tools page doubles as a rough receiver 
tester. Below are a number of results taken from this tool (thanks Bert for 
providing these logs). The most reliable way to test a receiver this way is 
to record a NMEA log of about 5 minutes at low speed including at least one 
turn of 90 degrees. The below results follow this directive and are 
recorded under quite similar conditions.

Note that a score above 50% is usable for our purposes. When no drifting 
deviation is present you should suspect some kind of Static Navigation set 
to on in the receiver. A receiver that has SN turned off will show some 
drift when standing still or going very slow.

Results:

5500-Royaltek-Rbt2300-nmea.log
Average NMEA data
The coverage during this trip was : 100%.
The accuracy during this trip was: 9 meters.
The number of satellites during this trip was: 10.
The speed during this trip was: 2.32 KM/H.
Average calculated data
Reliability score: 92%.
Moving heading deviation: 14 degrees.
Drifting heading deviation: 74 degrees.
Total heading deviation: 32 degrees.
Speed diviation: 1.07 KM/H

6680-Holux-GPSlim236-nmea.log
Average NMEA data
The coverage during this trip was : 100%.
The accuracy during this trip was: 9 meters.
The number of satellites during this trip was: 11.
The speed during this trip was: 3.06 KM/H.
Average calculated data
Reliability score: 95%.
Moving heading deviation: 9 degrees.
Drifting heading deviation: 57 degrees.
Total heading deviation: 20 degrees.
Speed diviation: 0.76 KM/H

E70-Royaltek-RBT2001-nmea.log
Average NMEA data
The coverage during this trip was : 100%.
The accuracy during this trip was: 9 meters.
The number of satellites during this trip was: 11.
The speed during this trip was: 3.05 KM/H.
Average calculated data
Reliability score: 94%.
Moving heading deviation: 11 degrees.
Drifting heading deviation: 49 degrees.
Total heading deviation: 18 degrees.
Speed diviation: 0.57 KM/H

N82-Holux-M1000-nmea.log
Average NMEA data
The coverage during this trip was : 100%.
The accuracy during this trip was: 10 meters.
The number of satellites during this trip was: 9.
The speed during this trip was: 2.68 KM/H.
Average calculated data
Reliability score: 86%.
Moving heading deviation: 25 degrees.
Drifting heading deviation: 29 degrees.
Total heading deviation: 25 degrees.
Speed diviation: 1.38 KM/H

N82-internal-aGPS-nmea.log
Average NMEA data
The coverage during this trip was : 100%.
The accuracy during this trip was: 18 meters.
The number of satellites during this trip was: 7.
The speed during this trip was: 2.72 KM/H.
Average calculated data
Reliability score: 52%.
Moving heading deviation: 10 degrees.
Drifting heading deviation: 23 degrees.
Total heading deviation: 10 degrees.
Speed diviation: 0.33 KM/H

By recording the suggested NMEA log and feeding that through the Breadcrumb 
generator you can test your receiver at:
http://www.loadstone-gps.com/tools/

Rob



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