| Topic: |
Science > Physics |
| User: |
"" |
| Date: |
24 Feb 2006 12:40:33 AM |
| Object: |
Triangulation of Broadcast Signal |
Is there any simple to use product for triangulating the precise
location of a radio or other air broadcast signal? barring that what
would be involved in making such a device as simply and cheaply as
possible?
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| User: "Helmut Wabnig" |
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| Title: Re: Triangulation of Broadcast Signal |
24 Feb 2006 03:16:37 AM |
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On 23 Feb 2006 22:40:33 -0800, wrote:
Is there any simple to use product for triangulating the precise
location of a radio or other air broadcast signal? barring that what
would be involved in making such a device as simply and cheaply as
possible?
The Britons used "Huff Duff" already in the Second World War.
"Huff Duff" 614 hits in Google
w.
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| User: "Tony" |
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| Title: Re: Triangulation of Broadcast Signal |
26 Feb 2006 04:11:24 PM |
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We call them ADFs in airplanes: automatic direction finders, and they
are off the shelf items. In aviation, off the shelf does not mean
cheap.
Here's an interesting idea. If you had only one ADF, and you knew the
physical locations of three nearby broadcast antennas, you can, just
knowing the angles the ADF displays can locate your geographic
position. Before the days of GPS we were fooling with this idea as an
easy position location device for sailboats. With memory as cheap as it
is today, one could just do a scan of broadcast stations and select
those signals that resolve to a reasonable geographic position.
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| User: "tadchem" |
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| Title: Re: Triangulation of Broadcast Signal |
24 Feb 2006 04:42:50 AM |
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You need a directional antenna. The more directional the better the
triangulation. 'Simple and cheap' are usually incompatible with
'precise and sensitive'.
Keep in mind that a triangle has three vertices, so you will need *two*
of them.
The 'best' design will depend on the actual frequency of the signal you
are triangulating.
Ham radio operators make a regular game of this.
Google "directional antenna"
Tom Davidson
Richmond, VA
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| User: "" |
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| Title: Re: Triangulation of Broadcast Signal |
24 Feb 2006 03:40:11 PM |
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What makes a directional antenna different from other antennas? What
variables of the design would depend on the frequency of the signal
being triangulated?
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| User: "tadchem" |
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| Title: Re: Triangulation of Broadcast Signal |
24 Feb 2006 04:00:44 PM |
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wrote:
What makes a directional antenna different from other antennas?
http://en.wikipedia.org/wiki/Directional_antenna
What
variables of the design would depend on the frequency of the signal
being triangulated?
http://en.wikipedia.org/wiki/Yagi_antenna
http://en.wikipedia.org/wiki/Log-periodic_antenna
http://en.wikipedia.org/wiki/Corner_reflector
Tom Davidson
Richmond, VA
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| User: "" |
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| Title: Re: Triangulation of Broadcast Signal |
24 Feb 2006 04:53:43 PM |
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I viewed each of these wikipedia links, but I'm still fairly clueless
what the freqeuncy changes in regards to the design. I get what a
directional antenna is and I can see how 2 would be used to triangulate
a position, but beyond that I'm lost.
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| User: "tadchem" |
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| Title: Re: Triangulation of Broadcast Signal |
25 Feb 2006 07:14:36 PM |
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frequency = speed of light / wavelength
Different frequencies have different wavelengths.
http://en.wikipedia.org/wiki/Dipole_antenna
tells you exactly how frequency relates to the physical dimensions of
the antenna.
Tom Davidson
Richmond, VA
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| User: "" |
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| Title: Re: Triangulation of Broadcast Signal |
26 Feb 2006 12:15:45 AM |
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How difficult would it be to track the position of a signal's moving
source?
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| User: "" |
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| Title: Re: Triangulation of Broadcast Signal |
26 Feb 2006 12:55:03 AM |
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wrote:
How difficult would it be to track the position of a signal's moving
source?
If the source moved,
the carrier frequency would be shifted by the Doppler Effect.
If each of the monitoring stations
tracked the frequency shifts,
and this data were combined and later analyzed,
or synchronized and later analyzed,
you could track the moving source.
Also, if it was known when the moving source
passed through a known point,
the tracking data would allow for a more accurate fix
than a directional antenna would.
The key would be how precisely the time bases in
the tracking stations could be synchronized.
If the target moved in a quasi random manner,
cross-correlations could be used to get the
tracking signals in sync.
--
Tom Potter
http://no-turtles.com
http://photos.yahoo.com/tdp1001
http://spaces.msn.com/tdp1001
http://tom-potter.blogspot.com
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| User: "" |
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| Title: Re: Triangulation of Broadcast Signal |
26 Feb 2006 01:30:12 AM |
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Is there any pc software available that can be combined with this input
to arrive at this info?
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| User: "" |
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| Title: Re: Triangulation of Broadcast Signal |
26 Feb 2006 06:20:57 AM |
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wrote:
Is there any pc software available that can be combined with this input
to arrive at this info?
There may be a cheap and simple answer to this,
but first tell me what you are tracking.
--
Tom Potter
http://no-turtles.com
http://photos.yahoo.com/tdp1001
http://spaces.msn.com/tdp1001
http://tom-potter.blogspot.com
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| User: "" |
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| Title: Re: Triangulation of Broadcast Signal |
26 Feb 2006 03:56:49 PM |
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I wanted to direct a R/C car or mini helicopter with a mini wireless
cam mounted on it. I further wanted to be able to use a program on a
pc to direct it automatically from point to point using input about its
location. This would be helpful when the R/C unit was out of view.
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| User: "Sam Wormley" |
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| Title: Re: Triangulation of Broadcast Signal |
26 Feb 2006 04:00:27 PM |
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wrote:
I wanted to direct a R/C car or mini helicopter with a mini wireless
cam mounted on it. I further wanted to be able to use a program on a
pc to direct it automatically from point to point using input about its
location. This would be helpful when the R/C unit was out of view.
Include onboard GPS receiver
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| User: "tadchem" |
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| Title: Re: Triangulation of Broadcast Signal |
26 Feb 2006 05:23:50 PM |
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Sam Wormley wrote:
mwmiller314@gmail.com wrote:
I wanted to direct a R/C car or mini helicopter with a mini wireless
cam mounted on it. I further wanted to be able to use a program on a
pc to direct it automatically from point to point using input about its
location. This would be helpful when the R/C unit was out of view.
Include onboard GPS receiver
That is the best solution. The techniques of triangulation are nest
suited to sources that do not *want* to be found.
A classic example of the fact that the quality of the answer is
determined by the quality of the question...
Tom Davidson
Richmond, VA
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| User: "" |
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| Title: Re: Triangulation of Broadcast Signal |
26 Feb 2006 05:58:08 PM |
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The cheapest gps device I found for this purpose was a 'gps beacon' for
like $500+ and I dont even know if it was small and lightweight enough.
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| User: "" |
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| Title: Re: Triangulation of Broadcast Signal |
26 Feb 2006 08:38:14 PM |
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wrote:
The cheapest gps device I found for this purpose was a 'gps beacon' for
like $500+ and I dont even know if it was small and lightweight enough.
I have seen Bluetooth GPS systems for less than $50.00,
and they are very small and light. In fact, you should be able
to use a raw GPS receiver chip to do this job.
It seems to me that you could send commands to the "plane"
to where you wanted it to go,
and have a circuit on the "plane" compare where it is,
based on the GPS output,
to the data you sent,
and have the controls react as a closed loop system.
That said, I hope you are not putting
bombs or anything dangerous on this plane".
--
Tom Potter
http://no-turtles.com
http://photos.yahoo.com/tdp1001
http://spaces.msn.com/tdp1001
http://tom-potter.blogspot.com
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| User: "" |
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| Title: Re: Triangulation of Broadcast Signal |
26 Feb 2006 09:32:29 PM |
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Can you tell me where you saw such a small lightweight system? (of the
variety that can send output to a pc)
tdp1001@gmail.com wrote:
mwmiller314@gmail.com wrote:
The cheapest gps device I found for this purpose was a 'gps beacon' for
like $500+ and I dont even know if it was small and lightweight enough.
I have seen Bluetooth GPS systems for less than $50.00,
and they are very small and light. In fact, you should be able
to use a raw GPS receiver chip to do this job.
It seems to me that you could send commands to the "plane"
to where you wanted it to go,
and have a circuit on the "plane" compare where it is,
based on the GPS output,
to the data you sent,
and have the controls react as a closed loop system.
That said, I hope you are not putting
bombs or anything dangerous on this plane".
--
Tom Potter
http://no-turtles.com
http://photos.yahoo.com/tdp1001
http://spaces.msn.com/tdp1001
http://tom-potter.blogspot.com
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| User: "" |
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| Title: Re: Triangulation of Broadcast Signal |
26 Feb 2006 10:44:38 PM |
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wrote:
Can you tell me where you saw such a small lightweight system? (of the
variety that can send output to a pc)
tdp1001@gmail.com wrote:
wrote:
The cheapest gps device I found for this purpose was a 'gps beacon' f=
or
like $500+ and I dont even know if it was small and lightweight enoug=
h=2E
I have seen Bluetooth GPS systems for less than $50.00,
and they are very small and light. In fact, you should be able
to use a raw GPS receiver chip to do this job.
It seems to me that you could send commands to the "plane"
to where you wanted it to go,
and have a circuit on the "plane" compare where it is,
based on the GPS output,
to the data you sent,
and have the controls react as a closed loop system.
That said, I hope you are not putting
bombs or anything dangerous on this plane".
If you do a Google search on "gps chipset",
you'll get hits like that below, and you'll also find data sheets that
tell how to interface GPS chipsets with computers and other devices.
As I indicated, it might be best to install the chipset on the "plane",
and integrate it with a closed loop system that has the "plane"
go to the coordinates you send.
It would be more complex and costly to transmit the GPS data
to a ground station receiver, decode the data, feed it into a computer,
compute the commands to send to the plane, modulate the ground
transmitter with the appropriate commands, etc.although this has the
advantage that you always know where your "plane" is.
If you don't send the "plane" off on a space warp,
(Give it time to get to your new coordinate.)
you should always know where it is anyway.
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
November 16, 2004
Expect Sub-$8 GPS Chipsets from Atmel and Thales by 2005 San Jose and
Santa Clara, Calif. -- Atmel=AE Corporation (Nasdaq: ATML) and Thales
have signed a technology agreement, under which the two companies will
partner in the development and marketing of state-of-the-art global
positioning system (GPS) chipsets, sub-systems and associated software.
Under the agreement Atmel will sell a GPS chipset solution originally
used in the Magellan=AE eXplorist=E4 recreational GPS handheld from
Thales, and jointly developed by Atmel and Thales.
Our goal is to exploit this rapid growth and to work with partners like
Atmel to become the provider of choice for GPS chipset solutions."
Bill Gross, Atmel's ASSP Marketing Manager, says of the agreement,
"In 2003, the average price of a GPS chipset was almost $21.00. Today
it is in the $17 range and next year it is expected to be about $14.00.
By combining Thales' superior GPS IP with our own IC foundry
capability, Atmel expects to bring that price down to $8 or less in
2005. We believe this substantially lower pricing will open major new
markets to GPS technology and will accelerate the already rapid growth
in the traditional GPS sectors."
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--
Tom Potter
http://no-turtles.com
http://photos.yahoo.com/tdp1001
http://spaces.msn.com/tdp1001
http://tom-potter.blogspot.com
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| User: "" |
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| Title: Re: Triangulation of Broadcast Signal |
27 Feb 2006 12:06:15 AM |
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wrote:
mwmiller314@gmail.com wrote:
Can you tell me where you saw such a small lightweight system? (of the
variety that can send output to a pc)
wrote:
mwmiller314@gmail.com wrote:
The cheapest gps device I found for this purpose was a 'gps beacon'=
for
like $500+ and I dont even know if it was small and lightweight eno=
ugh.
I have seen Bluetooth GPS systems for less than $50.00,
and they are very small and light. In fact, you should be able
to use a raw GPS receiver chip to do this job.
It seems to me that you could send commands to the "plane"
to where you wanted it to go,
and have a circuit on the "plane" compare where it is,
based on the GPS output,
to the data you sent,
and have the controls react as a closed loop system.
That said, I hope you are not putting
bombs or anything dangerous on this plane".
If you do a Google search on "gps chipset",
you'll get hits like that below, and you'll also find data sheets that
tell how to interface GPS chipsets with computers and other devices.
As I indicated, it might be best to install the chipset on the "plane",
and integrate it with a closed loop system that has the "plane"
go to the coordinates you send.
It would be more complex and costly to transmit the GPS data
to a ground station receiver, decode the data, feed it into a computer,
compute the commands to send to the plane, modulate the ground
transmitter with the appropriate commands, etc.although this has the
advantage that you always know where your "plane" is.
If you don't send the "plane" off on a space warp,
(Give it time to get to your new coordinate.)
you should always know where it is anyway.
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
November 16, 2004
Expect Sub-$8 GPS Chipsets from Atmel and Thales by 2005 San Jose and
Santa Clara, Calif. -- Atmel=AE Corporation (Nasdaq: ATML) and Thales
have signed a technology agreement, under which the two companies will
partner in the development and marketing of state-of-the-art global
positioning system (GPS) chipsets, sub-systems and associated software.
Under the agreement Atmel will sell a GPS chipset solution originally
used in the Magellan=AE eXplorist=E4 recreational GPS handheld from
Thales, and jointly developed by Atmel and Thales.
Our goal is to exploit this rapid growth and to work with partners like
Atmel to become the provider of choice for GPS chipset solutions."
Bill Gross, Atmel's ASSP Marketing Manager, says of the agreement,
"In 2003, the average price of a GPS chipset was almost $21.00. Today
it is in the $17 range and next year it is expected to be about $14.00.
By combining Thales' superior GPS IP with our own IC foundry
capability, Atmel expects to bring that price down to $8 or less in
2005. We believe this substantially lower pricing will open major new
markets to GPS technology and will accelerate the already rapid growth
in the traditional GPS sectors."
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--
Tom Potter
http://no-turtles.com
http://photos.yahoo.com/tdp1001
http://spaces.msn.com/tdp1001
http://tom-potter.blogspot.com
Your suggested plan seems to reduce overall resources needed by
eliminating any dependence on a computer, however, I have no experience
with acquiring or making circuits for specialized purposes. I imagine
it wouldn't be wildly expensive, but I'm not totally sure it's the
cheaper option. Any further input would be appreciated.
.
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| User: "" |
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| Title: Re: Triangulation of Broadcast Signal |
27 Feb 2006 03:01:47 AM |
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wrote:
tdp1001@gmail.com wrote:
wrote:
Can you tell me where you saw such a small lightweight system? (of the
variety that can send output to a pc)
tdp1001@gmail.com wrote:
wrote:
The cheapest gps device I found for this purpose was a 'gps beaco=
n' for
like $500+ and I dont even know if it was small and lightweight e=
nough.
I have seen Bluetooth GPS systems for less than $50.00,
and they are very small and light. In fact, you should be able
to use a raw GPS receiver chip to do this job.
It seems to me that you could send commands to the "plane"
to where you wanted it to go,
and have a circuit on the "plane" compare where it is,
based on the GPS output,
to the data you sent,
and have the controls react as a closed loop system.
That said, I hope you are not putting
bombs or anything dangerous on this plane".
If you do a Google search on "gps chipset",
you'll get hits like that below, and you'll also find data sheets that
tell how to interface GPS chipsets with computers and other devices.
As I indicated, it might be best to install the chipset on the "plane",
and integrate it with a closed loop system that has the "plane"
go to the coordinates you send.
It would be more complex and costly to transmit the GPS data
to a ground station receiver, decode the data, feed it into a computer,
compute the commands to send to the plane, modulate the ground
transmitter with the appropriate commands, etc.although this has the
advantage that you always know where your "plane" is.
If you don't send the "plane" off on a space warp,
(Give it time to get to your new coordinate.)
you should always know where it is anyway.
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
November 16, 2004
Expect Sub-$8 GPS Chipsets from Atmel and Thales by 2005 San Jose and
Santa Clara, Calif. -- Atmel=AE Corporation (Nasdaq: ATML) and Thales
have signed a technology agreement, under which the two companies will
partner in the development and marketing of state-of-the-art global
positioning system (GPS) chipsets, sub-systems and associated software.
Under the agreement Atmel will sell a GPS chipset solution originally
used in the Magellan=AE eXplorist=E4 recreational GPS handheld from
Thales, and jointly developed by Atmel and Thales.
Our goal is to exploit this rapid growth and to work with partners like
Atmel to become the provider of choice for GPS chipset solutions."
Bill Gross, Atmel's ASSP Marketing Manager, says of the agreement,
"In 2003, the average price of a GPS chipset was almost $21.00. Today
it is in the $17 range and next year it is expected to be about $14.00.
By combining Thales' superior GPS IP with our own IC foundry
capability, Atmel expects to bring that price down to $8 or less in
2005. We believe this substantially lower pricing will open major new
markets to GPS technology and will accelerate the already rapid growth
in the traditional GPS sectors."
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--
Tom Potter
http://no-turtles.com
http://photos.yahoo.com/tdp1001
http://spaces.msn.com/tdp1001
http://tom-potter.blogspot.com
Your suggested plan seems to reduce overall resources needed by
eliminating any dependence on a computer, however, I have no experience
with acquiring or making circuits for specialized purposes. I imagine
it wouldn't be wildly expensive, but I'm not totally sure it's the
cheaper option. Any further input would be appreciated.
Find some young engineer, or even technician,
and work with him to make a system that
you think others will want,
and you two guys make and sell these systems to them.
Any good digital technician could build this system.
In fact, make a post in one of the electronic groups and
someone might want to work with you.
If you think this system is useful,
but not available,
it is certain that many others will want it.
It's not that hard a system to build,
nor will the parts cost very much.
In fact, you could program flight paths ,
as data tables or drawings,
read them with a PC and drive a
transmitter via the USB or serial port
and have the plane fly a programmed course.
There would also be many commercial, law enforcement,
and military applications for a low cost programmed path airplane.
--
Tom Potter
http://no-turtles.com
http://photos.yahoo.com/tdp1001
http://spaces.msn.com/tdp1001
http://tom-potter.blogspot.com
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| User: "tadchem" |
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| Title: Re: Triangulation of Broadcast Signal |
26 Feb 2006 02:51:30 PM |
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wrote:
How difficult would it be to track the position of a signal's moving
source?
That will depend on how fast the source is moving and how fast you can
get direction readings from multiple locations.
The situation you are describing sounds like the triangulation done on
terrestrial transmitters. If the source is not terrestrial, then it
will be impossible to separate two or more antennas far enough to get a
good triangulation baseline unless you are working with microwaves or
higher frequencies and therefore able to use dish antennas and
interferometric techniques. [Google "very large array" for more on
this.]
Directional antennas are engineered to be selective in direction for a
certain bandwidth, not highly selective for frequency. Frequency
selection is normally done 'downstream' in the electronics. May I
presume that the source will NOT be moving fast enough for doppler
frequency shifts to be significant?
Each directional antenna will be able to provide a direction towards
the source (possibly with some aliasing - you may for example be able
to determine that the soure is north OR south of you position, but not
which), valid at the moment the reading is made. If the source is
moving, those directional readings become invalid almost immediately.
A triangulation will require a minimum of two separate direction
readings from two separate positions. If one has three directional
readings imultaneously, so much the better.
If the source is moving, these readings should be as close as possible
to simultaneous to give an approximate position at the time the
readings are made.
To *track* the motion of the source, multiple triangulations need to be
made and recorded. Maps are useful tools for plotting. Plot the
location of each antenna on the map. Then plot the direction readings
from each antenna as lines passing through the antenna sites. The
source is probably close to the place where the lines intersect. A
third line for a third antenna will in general NOT intersect the same
point as the one where the first two lines intersect. You are most
likely to see a triangle. Since the source will be close to all three
lines, it will most likely be *inside* the triangle formed by the three
bearing lines.
Each approximate determination represents the most probable location of
the source at a specific time. Track the motion of the source amounts
to plotting its location as a function of time.
Tom Davidson
Richmond, VA
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