Determination of location & distance from transmitter
Determination of location & distance from transmitter
(OP)
Hello
Is it possible to determine the distance to a transmitter, from receiver by analysing the wavelength of the signal received?
For example, this process used to determine the location of an airplane. However, is it possible to use the same principles to determine distance or location in a smaller range, say within a metre?
Are there any standard components or common applications that allow for this?
FYI, The application is for a animal/laboratory experiment to track the location of animals.
Thank you in advance for any help
Is it possible to determine the distance to a transmitter, from receiver by analysing the wavelength of the signal received?
For example, this process used to determine the location of an airplane. However, is it possible to use the same principles to determine distance or location in a smaller range, say within a metre?
Are there any standard components or common applications that allow for this?
FYI, The application is for a animal/laboratory experiment to track the location of animals.
Thank you in advance for any help





RE: Determination of location & distance from transmitter
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Determination of location & distance from transmitter
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Determination of location & distance from transmitter
RE: Determination of location & distance from transmitter
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Determination of location & distance from transmitter
TTFN

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RE: Determination of location & distance from transmitter
Thank you for this suggestion, though I am looking for something very short range, within a a few metres of the receiver and very very accurate positioning (within a few mm)
RE: Determination of location & distance from transmitter
If the amplitude could be measured and the wavelenght is known then * in theory * it ought to be possible to measure how many wavelengths (and parts thereof) the distance is.
RE: Determination of location & distance from transmitter
Well, then I'm afraid you'll have to find this theory and show it to us. If I have a radio wave with strength 2V/m and wavelength 300mm how do I determine how far the transmitter is from me?
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Determination of location & distance from transmitter
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Determination of location & distance from transmitter
Well, then I'm afraid you'll have to find this theory and show it to us. If I have a radio wave with strength 2V/m and wavelength 300mm how do I determine how far the transmitter is from me? >>
How with triangulation using many receivers? And (if necessary) using dual frequencies to produce constructive / destructive wave patterns to provide further information.
RE: Determination of location & distance from transmitter
< you'll have to find this theory and show it to us. If I have a radio wave with strength 2V/m and wavelength 300mm how do I determine how far the transmitter is from me? >
1. Take the case where the 300mm wave starts at peak amplitude, and arrives at the receiver 180 degrees out of phase. There are a range of possible distances, 150mm, 450mm, 750,mm …. Amounting to radiating concentric circles in 2 dimensions.
2. Triangulation ought to be able to be possible to determine the qualifying distance given that the approximate distance is known from the outset.
As far as I can tell, this rests only on the assumption that the waves amplitude or position is measureable via its signal strength using standard componentry.
RE: Determination of location & distance from transmitter
How do you know the relative phase? Think about it very carefully. You'll soon realize you're in a logical circle.
"...very very accurate positioning (within a few mm)..."
The larger picture is that someone needs to invent the technology you're asking for; probably not you unless you have a huge amount of time. It'll be optical to be mm-accurate.
What kind of animals need to be tracked to with a few mm? Elephants? Insects?
Is this for school?
RE: Determination of location & distance from transmitter
At a previous job we tested something like this on a very large scale (though the transponder was about the size of a thumb/flash drive) and it worked very well.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Determination of location & distance from transmitter
1. Just consider the case where you are 10 wavelengths away; you still see the same frequency, but lower amplitude; this is classic range ambiguity in interferometry. I think you are confusing interferometry with general range measurements. Interferometry only deals with distance measurement over a single wavelength, by using phase comparison; beyond that first wavelength, you must use either another wavelength or another means to deal with range ambiguity. In your example, a 300 mm wavelength could probably be accurately measured to 3mm, but you can achieve better than that with a conventional laser range finder.
2. Triangulation uses ASA to determine range, without using wavelength whatsoever.
TTFN

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RE: Determination of location & distance from transmitter
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Determination of location & distance from transmitter
Can I ask, what was the means for determination of distance from transponders, was it Radiolocation involving RSSI, TOA and AOA?
A pet microchip is very small. Conceivably, could the transponders be smaller than a USB drive?
RE: Determination of location & distance from transmitter
Surely, Triangulation need not be limited to ASA? Putting aside Wavelenght, what is the most expedient way of finding distance?
RE: Determination of location & distance from transmitter
Some of us may be concerned that your requirements push the limits of the state of the art, but your questions are relatively basic.
RE: Determination of location & distance from transmitter
ASA; which is how the great Everest, etal, systematically performed the Great Survey of India, which was before anyone had even radios. Of course, the ultimate cost of the survey nearly bankrupted the British East Indies company.
Of course, for the short distance the OP seems to be implying, there's this:
https://www.mysick.com/partnerPortal/ProductCatalo...
I've never been clear how Sick does it; I presume it's doing an FMCW approach.
TTFN

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RE: Determination of location & distance from transmitter
As a general point, an accuracy/repeatability of 1mm in 2d or 3d over the length of 5m is not possible with non contacting methods with finite budgets. To get that we use Faro Arms, which would be no good for dynamic measurements.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Determination of location & distance from transmitter
RE: Determination of location & distance from transmitter
I've never been clear how Sick does it; I presume it's doing an FMCW approach.>
Thank you for this lead, FMCW appears to be very relevant.>
RE: Determination of location & distance from transmitter
No intention of pushing the state of the art, only to define the limits of standard process.
< write a spec>
Yes. I will, though for now:
Range: 800mm
Accuracy: 1mm
2 dimensions.
Many thanks to all for the detailed leads and help
RE: Determination of location & distance from transmitter
RE: Determination of location & distance from transmitter
Yes, a very simple practical approach - thank you!