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[aprssig] Signal Locator WEB page

Robert Bruninga bruninga at usna.edu
Thu Apr 26 21:34:00 UTC 2007


> A few years ago, there was a UI-View add-on, DF Plot. 
> Any number of mobiles, with ordinary Fox Hunting 
> equipment, radio, directional antenna, and a knowledge 
> of "where" the hunter is, would report the bearing 
> from that spot to a central UI-View operator running 
> the DF Plot.

Does the Uiview DF-Plot add-on also do the basic APRS OMNI-DF
overlaping Signal Strength contours?  

The technique noted above depends on properly equiped mobile DF
units with lots of equipment.  I basically gave up on that way
back in the 1995 time frame, since we never had the equipment or
the people when it was needed.

So we added OMNI-Dfing to APRS in hope that APRS could
concentrate on its knowledge of position of -everyone- and
what-they-hear and Antenna-Height Range as a much more reliable
come-as-you-are method of signal origination localization.  Too
bad it was not universally implemented in all APRS clients so
that we could be doing this at the push of a button within
seconds of hearing a request for signal info.. :-(

Uiview doesn't even provide the fundamental antenna height and
coverage info without people loading an add-on.  And without
being able to see instantly what approximate area coverage each
home station has, then it is hopeless to make any sense out of
Uiview stations.

Checking the DC/Balto area and 235 stations on the air, only 5
Uiview stations are transmitting their PHG data.  The other 60
it is impossible to tell if they have a good station/antenna
hearing out to 50 miles, or hearing out to 1 mile using a rubber
duck in the basement.  They all look the same.

And even if these people did want to make an OMNI DF report,
Uiview without the add-on has no input box for making the report
and no PHG data on which to base it.

So that is why APRS as a group still cannot do simple signal
localizing which can work so well and  is so easy to do.  That
is why I give up and ask that at least someone implemnet it in a
browser application so that we can really nail these signals as
it would be so easy to do...  Surely someone might be looking
for a neat project that will revolutionize HAM radio Dfing...

Bob


> As these reports come in, the operator would report the 
> location of the 
> crosshair plot of these reports back to the hunters. If these
mobiles 
> are using APRS tracking gear, then the UI-View operator only
needs to 
> click on the reporting tracker, enter the bearing reported by
the 
> tracker into DF Plot. For those running mobile mapping, an 
> object will 
> be placed where the bearings all intersect..
> 
> For those not running mobile mapping, someone can can direct 
> the hunters 
> by voice when needed on another frequency..
> 
> Robbie
> 
> R. Simmons wrote:
> 
> > From an outsider : IMHO I agree the DF abilities of APRS 
> have not been
> >cultivated and are largely dormant. I have long salivated 
> over the prospect
> >of an effective web-based display with multi-hunter APRS 
> inputs. Last year I
> >succeeded in making a simple PIC-based device that generates 
> APRS-compliant
> >DF messages, and tested it successfully. It was detected and 
> plotted on
> >FINDU.com, but with no DF bearing line. I could pursue it 
> further and easily
> >offer it as a finished product, but without a means of 
> display, it would be
> >pretty pointless.
> >
> > Furthermore, I think hams generally don't co-operate on 
> hunts, they compete
> >against each other, ( = social hunts for fun ) so the skills
( and
> >technology ) required for a co-ordinated "team hunt" never
really get
> >developed.
> >
> >Bob S.
> >
> >
> >----- Original Message -----
> >From: "Robert Bruninga" <bruninga at usna.edu>
> >To: "'TAPR APRS Mailing List'" <aprssig at lists.tapr.org>
> >Sent: Thursday, April 26, 2007 8:17 AM
> >Subject: [aprssig] Signal Locator WEB page
> >
> >
> >  
> >
> >>WEB based APRS Direction Finder
> >>
> >>APRS has a rich set of Direction Finding tools that have not
> >>been implemented in many APRS clients.  As such, these
powerful
> >>techniques are rarely used by most operators.
> >>
> >>However, if we had a WEB based Direction Finder DISPLAY
system
> >>tied into the APRS-IS, then we would not only leverage the
power
> >>of APRS DFing, but then ALL ham radio operators in the area
> >>could see the developing solution in real time and we would
get
> >>10 times as much data input!
> >>
> >>Please see the OMNI-Dfin technique in APRS:
> >>http://www.ew.usna.edu/~bruninga/dfing.html
> >>
> >>The web page would draw the map with the overlaping signal
> >>strength contours reported by APRS packets.  Browser based
> >>stations could also enter their report on the same web page
and
> >>add to the display of contours.
> >>
> >>This narrows the area down very rapidly to a mile or so.
> >>
> >>Any takers?  It really does work.  And all it needs is input
> >>from people that have or HAVE NOT heard the signal.  A
reliable
> >>NOT-HEARD report is even more valuable than a heard report,
> >>because it blacks out a larger area of where the signal
> >>cannot-be.  Enough of these, and you can eliminate so much
area,
> >>that it is easy then to focus mnore carefully on where the
> >>signal may be.
> >>
> >>I sure wish I knew how to write active web pages like that.
TO
> >>me, this would be the biggest asset for HAM radio 3rd to
> >>tracking, and Weather on APRS.
> >>
> >>Bob, WB4APR
> >>
> >>
> >>
> >>
> >>
> >>_______________________________________________
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> >>https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig
> >>
> >>    
> >>
> >
> >
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> >
> >  
> >
> 
> 
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