Shop OBEX P1 Docs P2 Docs Learn Events
Is it possible and legal to reproduce the signal of 4 GPS satalites in a whereh — Parallax Forums

Is it possible and legal to reproduce the signal of 4 GPS satalites in a whereh

Capt. QuirkCapt. Quirk Posts: 872
edited 2008-07-16 11:24 in General Discussion
I would like to do some experiments with GPS navigation indoors, but I don't know if it would cause problems outdoors or if I would need a permit?

Bill

Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-07-15 23:10
    If your warehouse (although "wherehouse" does seem oddly appropriate when discussing GPS smile.gif ) were seamlessly lined with grounded copper so the signals couldn't escape, you might get by with it. But in practical terms, you'd likely be in trouble both technically (GPS signals are not the least bit simple to produce) and legally, if you attempted what you seem to be suggesting.

    What is your end goal in all of this, BTW? Maybe there's another way to get there.

    -Phil

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    'Still some PropSTICK Kit bare PCBs left!
  • Capt. QuirkCapt. Quirk Posts: 872
    edited 2008-07-16 00:43
    I wanted to put together a high speed autonomous robot race, on an indoor go kart track. Gps was one idea,·another possibility·was Data aquisition based off of a run by radio control and then, reprogram the bot with the data (like some of the Firsties do). Then the bot would have to have some colision capabilities to remain ontrack.

    Any other ideas?

    ·
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2008-07-16 01:10
    A variation on D-M-E?·

    http://en.wikipedia.org/wiki/Glideslope

    ·
  • computer guycomputer guy Posts: 1,113
    edited 2008-07-16 01:14
    I don't think that using GPS at such a close range would work.
    GPS works on the delay for the signal to get from the satellites to the receiver.
    With the signal being generated only meters away the delay wouldn't be large enough to triangulate the position.

    You could try and make your own system using xbee's or something and go off signal strength but working out the position might be hard.

    All I can say is good luck. smile.gif

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Building Blocks To The Propeller Chip A web site designed to help people who are new to the propeller chip.

    Guitar Hero controller using the prop (WIP) --> HERE
  • Capt. QuirkCapt. Quirk Posts: 872
    edited 2008-07-16 01:58
    That looks feasible, the wiki said a DME signal travels at 12.36us / mile. I suppose any radio signal in a building would be really fast. After reading that page I think I could also create 4 quadrants, similar to ILS, using tv antennas. But I have no idea how accurate that would be.

    I need to do more research.
  • Capt. QuirkCapt. Quirk Posts: 872
    edited 2008-07-16 02:19
    Computer guy,

    I was realizing that while I was reading PJ Allens link.

    What if I used·3 or 5 RF recievers-transmitters that were programed to respond to a signal after a programed delay (like the DME). That way the bot would always be able to measure the send - delay - return time in a predetermined order.·If·a Propeller counter, is able to make sense of the nano sec differences from 3 to 5 sequential sources?


    Post Edited (Capt. Quirk) : 7/16/2008 2:25:10 AM GMT
  • sylvie369sylvie369 Posts: 1,622
    edited 2008-07-16 11:24
    Take a look at this thread:

    http://forums.parallax.com/showthread.php?p=723969
Sign In or Register to comment.