Hrm, power may be an issue. 300 meters distance should suffice as a
starting point for the first generation.
The product will start in the United States. If the commercial
implementation works well, then it may go beyond the U.S. borders.
The device should be active for no more than 6-8 hours. If the device is
not passive, then it's power source needs to either be rechargable,
replaceable, or the entire unit should be so cheap that the whole TX unit
can be replaced.
It seems that if it only transmits when asked, then it is most likely a
passive unit. The advantages of passive units are smaller size, however,
distance is lost with lower powered transmitters. I have yet to determine
if it needs to only TX when asked, or not. I read that some passive RFID
units can both RX/TX on the same aerial, which requires extra engineering.
I shall answer the other questions, which may help find an answer to this
one.
Pulse would save power, which would also allow for a smaller unit.
Maximum size ... well, ideally paper thin and the entire TX unit to weigh
under 1 gram. The unit will also have to have other properties which may
add to the weight.
The tracking device will be placed on moving objects which will require
special properties (probably some type of glue (glue is not heavy also))
in order to stay affixed. It is not initially important that the units be
concealed, but because they are small, they may be difficult to visually
locate. Also, the operating environment will vary, extremely. This
variance is also a cause for concern, especially when considering the
power source.
There are a couple different concepts i have been pondering, regarding DF
(direction finding). What will probably happen is that the basic system
will include one handheld unit which will use, yes, signal strength for
DF. Later, if the product works, i would like to see a more involved
system of three or so units strategically located to allow for a type of
triangulation. Then, there is another concept i have which will have the
units network with one another and pass various information to each other,
which will allow for a mesh-like DF.
Thank you very much for your response(s).
.times enemy
> Hi,
>
> Half a mile will need 80~100 milliWatts
> A passive/reflective RFID-style device will not work at that distance
>
> Tell me where you are...to determine a legal frequency-band (if wanted)
>
> More details needed:
>
> How long should the device be active (TX)
> Should it only TX when asked (by other TX) that will need a receiver on
each as well
> Continious or pulses (TX every few sec's ?)
> Maximal size
> Where is the tag/tracker put (hidden ?)
> How will you DF just with signal-strength ?
>
> Tetrascanner
> http://www.tetrascanner.com
> http://groups.yahoo.com/group/gsm-scanner
> http://groups.yahoo.com/group/traffic-cams
> http://groups.yahoo.com/group/iPod-video
> http://groups.yahoo.com/group/ICOM-IC-R1500
Received on Sat Mar 02 2024 - 00:57:22 CST