Results 1 to 8 of 8

Thread: My "NEW" GPS says i'm sinking?

  1. #1
    Constant Bitrate jboy's Avatar
    Join Date
    Oct 2001
    Location
    MA
    Posts
    151

    My "NEW" GPS says i'm sinking?

    I just got a rand mcnally streetfinder delux 2000
    since i started it the altude has slowly droped from 185' to 110' and mapped a trail three times around my house with a quick trip to my neighbors garrage (musta had to take a leak)
    Anyone else ever have this happen?
    I only get 5-6 sat signals at 50-70% strength. Is this enough?

    down to 45' Soon I'll be waterfront!

  2. #2
    FLAC
    Join Date
    Apr 2001
    Location
    Here, There, Everywhere
    Posts
    1,436

    Re: My "NEW" GPS says i'm sinking?

    cant help with a solution.... but you sure gave me a good larf!!!
    Project - GAME OVER :(

  3. #3
    Rob
    Rob is offline
    Maximum Bitrate Rob's Avatar
    Join Date
    Aug 2001
    Location
    Missing In Action
    Posts
    779

    Re: My "NEW" GPS says i'm sinking?

    Originally posted by jboy
    I only get 5-6 sat signals at 50-70% strength. Is this enough?

    down to 45' Soon I'll be waterfront!
    I'm not 100% certain but I think GPS should work with 3 or more sat signals, due to triangulation.

    Might be worth fitting an out board to your car!
    And you say people actually pay money for M$ Windows?
    www.mp3mini.co.uk (Does what it says on the URL) www.openclassic.co.uk (The new car, with zero rust!) www.rob-web.co.uk (My other site)
    Total re-design underway: on the whole progress is very slow as the car is taking up too much time :)

  4. #4
    FLAC PatO's Avatar
    Join Date
    Dec 2000
    Location
    Afton MN
    Posts
    1,120
    I used a hand held garmin GPS a few years ago and I recall it not being terribly accurate with elevations. Almost always off by several hundred feet. Horizontal accuracy is typically good down to a few meters, but this can improve if they have the sensitivities turned up on the satelites. (Military action going on right now, so you'd think they'd have it cranked up to full...)
    http://www.jeepmp3.com/
    CarPC Stolen. Starting over.
    Ne1 recognize the avatar?

  5. #5
    FLAC MP3DUB's Avatar
    Join Date
    Jan 2002
    Location
    Chicagoland, IL
    Posts
    1,783
    I could be completely mistaken, but a military gps, besides being quite a bit more expensive than your average gps, also have the ability to use the completely accurate data that the satelites send (yes, they turned off the largest scrambling back in 2000, but I was under the impression that there was still some uncertancy introduced into the signal for civilian use).
    -Nick

    _____________________________
    Since when is insanity a bad thing?
    www.mp3vw.com

  6. #6
    FLAC DodgeCummins's Avatar
    Join Date
    Oct 2000
    Location
    DFW area
    Posts
    1,386
    That is normal.

    Even the Mil-spec GPS is only so accurate. If you are moving, then it can do math and get a fairly accurate position.

    If you are standing still, it is still doing the same math, but a couple of decimal points error in one of the 3 axis (6 directions) causes your gps's location to move . The average (center perhaps) of all these points is still pretty accurate, but it will drift a bit.

    The more satellites you are receiving the more accurate the math will be, If you have a gps signal on a ground station at an exact latitude and longitude, you increase your accuracy a bunch...but who can afford one of those.

  7. #7
    Variable Bitrate
    Join Date
    Mar 2001
    Posts
    292
    Pretty much what Dodge said.

    There's inaccuracies, particularly when not in motion. When in motion it will be more accurate. In any case, elevation will be off by more than any other. More satellites will increase your accuracy also.

    The average of all your positions when stationary will show your true position at the accuracy you'd expect.
    Player: Celeron II 633MHz, 256MB RAM, 20GB IBM 9mm 2.5" Laptop HD (180G/2ms), onboard ethernet/sound/video/tvout, 10"11"x3" case, MPBS1 70W DC-DC PS w/auto-shutdown controller, in-dash lighted switches, 7" NTSC TFT widescreen in-dash LCD, touchscreen, rear-window brake light installed Garmin GPS35 GPS, credit card sized IR remote w/IRMan, mini-wireless keyboard/mouse (sits under seat), PowerMate black knob, MP3s and GPS Navigation (Winamp, CoPilot, SA8.0).
    Car: 1993 Nissan Maxima, Black Emerald

  8. #8
    Constant Bitrate
    Join Date
    Nov 2000
    Location
    Ottawa, ON, CA
    Posts
    142
    Just as a sidenote - Anybody who is purchasing a new GPS unit should buy one with WAAS (wide area augmentation system) built-in .. it allows for 3m accuracy .. the WAAS is currently active and my Garmin eXtrex Venture locks to 3m up in Ottawa (the WAAS _is_ somewhat area dependant .. almost full US coverage and lower portion of Canada)

    If you're really crazy about elevation there is a Garmin model with an altimiter built-in ;-)
    -James-

    Tech tips and more - http://www.techguys.ca

    *NIX command for today: rm -rf /bin/laden

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •