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Article #2011Re: Using RSSI to locate an object
From: Joe G (Home)
Date: Tue, 20 Mar 2007 07:42
Date: Tue, 20 Mar 2007 07:42
47 lines
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2772 bytes
"Frank Raffaeli" <SNIPrf_man_frTHIS@yahoo.com> wrote in message news:1174357392.791589.126290@o5g2000hsb.googlegroups.com... > On Mar 19, 8:03 pm, "Josh916" <jka...@gmail.com> wrote: >> I would like to use RSSI to locate an object in a 3D space. The space >> will be a square box with transmitters located on the 4 corners. An >> object will be place at certain positions within the box and I want to >> be able to determine its location inside the box. Much like an >> internal GPS. >> >> I would like to know what components (IC's?) I need to perform such a >> task. >> >> Or if anyone else has any other more effective methods to acheive such >> a task your comments are welcomed. >> >> Thanks, >> >> Josh > > RSSI will indicate only the received signal strength, not distance - > and there are a lot of reasons why an accurate position indicator is > impractical using only this method, especially in the near field of > the TX antennas. > > It certainly won't work for VHF and above. I have had some success > with short range position indicators using 125 kHz sources. If that is > feasible for you, please indicate the dimensions you are working with. > > Frank Raffaeli > http://www.aomwireless.com/ > Yes, Frank is correct. If the signal is attenuated in any way.... (eg by antena beam width, objects absorbing RF, RF reflections causing canceling or summing effect) then your accruacy using RSSI will be shot. You should read up on the internet about how GPS using timed signals and sequences work to compute location. There are so may problems using RSSI accurately for distance. Regards Joe
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X-Google-Thread: 112d1e,99b7ff176446d3ef X-Google-Thread: 103407,99b7ff176446d3ef X-Google-Thread: 111d0a,99b7ff176446d3ef X-Google-Attributes: gid112d1e,gid103407,gid111d0a,public X-Google-Language: ENGLISH,ASCII-7-bit Path: arc1-ca.pugleaf.net!g2news1.google.com!news3.google.com!border1.nntp.dca.giganews.com!border2.nntp.dca.giganews.com!nntp.giganews.com!news1.optus.net.au!optus!newsfeeder.syd.optusnet.com.au!news.optusnet.com.au!not-for-mail From: "Joe G \(Home\)" <joe.g@optusnet.com.au> Newsgroups: sci.electronics.design,aus.electronics,sci.electronics.basics References: <1174348989.871006.52080@n76g2000hsh.googlegroups.com> <1174357392.791589.126290@o5g2000hsb.googlegroups.com> Subject: Re: Using RSSI to locate an object Date: Tue, 20 Mar 2007 18:42:04 +1100 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.3028 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-RFC2646: Format=Flowed; Original Lines: 49 Message-ID: <45ff904a$0$16552$afc38c87@news.optusnet.com.au> NNTP-Posting-Host: 58.106.64.138 X-Trace: 1174376522 16552 58.106.64.138