On Wed, 1 Sep 2010 10:30:59 +0100, "N_Cook" wrote:
I hope LW RDF is still going , I liked the morse ident feature and its
simplicity. I doubt , over some distance , it is any less accurate than
Loran and no hyperbolic plots to deal with
Yep. They're still alive and well. I still have a Taiho automagic
mechanically rotating LW RDF that I use for demonstrations. It's fun
to watch the loop seek and maybe point. Some of the LW beacon
stations are sending DGPS which have largely been replaced by WAAS
technology. Hearing LW beacons more than a few miles from shore is
tricky without a big antenna. You would probably be more successful
using AM, FM, and TV stations for coastline navigation, than using the
few LW stations.
http://www.beaconworld.fotopic.net/list_collections.php
Incidentally, the big problem with Loran-C was that it really didn't
work more than about 100 miles offshore. That limitation sold
considerable number of (pre-GPS) Transit and Omega systems as "backup"
for Loran-C. At least they worked in mid ocean. Incidentally, I
still have my Tamaya sextant and a Magnavox TRANSIT receiver in
storage.
If you want to do it thyself, it's possible to do 2D TRANSIT(NAVSAT)
doppler navigation if you can hear some LEO satellites, know the
Keplarian elements, and can accurately measure and record the doppler
shift as it passes overhead, using triangulation and trilateration.
The NIMS system may still be alive on 149.985 and 399.970 with
telemetry on 136.650 MHz although Keps appear to be lacking:
http://www.zarya.info/Frequencies/Frequencies150.php
Have your spherical geometry reference book handy. I've never
actually tried it, but it should be possible:
http://en.wikipedia.org/wiki/Trilateration
The Origins of GPS:
http://www.gpsworld.com/gnss-system/gps-modernization/the-origins-gps-part-1-9890
http://www.gpsworld.com/gnss-system/gps-modernization/the-origins-gps-part-2-fighting-survive-10010
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558