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PMB-648 Altitude reading accuracy — Parallax Forums

PMB-648 Altitude reading accuracy

Ron CzapalaRon Czapala Posts: 2,418
edited 2013-09-03 07:38 in Accessories
Does anyone have any insight as to why the altitude data varies so greatly using the PMB-648 GPS module?

Over the last couple of days it has returned values ranging from 177 meters to 209 meters while sitting on my desk.

I know that data comes from GCA sentence.

Thanks,
Ron

http://www.gpsinformation.org/dale/nmea.htm#GGA

Comments

  • PublisonPublison Posts: 12,366
    edited 2013-09-03 07:14
    Ron,

    Do an advance search on GPS, accuracy, altitude. There have been many discussions about it. The accuracy is just not there, you need a barometric sensor for accurate readings. Also, you will get more accurate reading if the GPS is moving. My Parallax GPS will vary 100 meters if it is not moving.

    Jim
  • Ron CzapalaRon Czapala Posts: 2,418
    edited 2013-09-03 07:38
    Publison wrote: »
    Ron,

    Do an advance search on GPS, accuracy, altitude. There have been many discussions about it. The accuracy is just not there, you need a barometric sensor for accurate readings. Also, you will get more accurate reading if the GPS is moving. My Parallax GPS will vary 100 meters if it is not moving.

    Jim

    Thanks Jim.

    I wasn't sure if some sort of calculation adjustment was needed or whether it just wasn't reliable.

    I do the advanced search and check it out.
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