Test Result of the EM-406A SiRF III Receiver

GPS/GNSS Development Boards
1

I purchased the EM-406A GPS receiver a while back and I wanted to report what I found.

This receiver has unbelievable tracking. I work in the basement of my 3 story house. It’s nearly impossible to make this module loose lock from the satellites. I even ran an experiment where I pushed a piece of aluminum foil over the top antenna side. Bottom side was laying on the table, so it wasn’t a total Gaussian shield.

Still, it stayed locked, although barely. It only lost lock when I pressed the foil down with my hands in place over top of it and leaned my body over the whole setup.

It was also very easy to use… power, ground & data is all you really need. Standard NMEA sentence output. I warm-start the module all the time (i.e. it’s had a lock recently, but I power down & back up again). It warm-starts & locks in just a few seconds.

  • Bart
2

The real test for a GPS is in so-called “urban canyons”, like street level in Manhattan with all those steel-framed skyscrapers attenuating the signals. u-blox modules are widely used in those situations because of their performance.

Leon

3

Yea, I agree. My test probably didn’t have a lot of multi-path interference like you’d find in a city with many reflectors and high path attenuation.

But still, I was impressed. None of my Garmin handhelds could do that!!!

4

The latest u-blox modules have -160 dbm sensitivity and special software with 50 million correlators:

http://www.u-blox.com/en/supersense.html

Do you have the figure for that module you are using?

Leon