Ham Radio 2000/Ham Radio 2000.iso/ham2000/packet/aprs75c/boats.txt

Text File | 1995-05-05 | 10KB | 158 lines

README.WWN      SUGGESTED USE OF APRS IN THE WATERWAY NET

APRS is the perfect tool for passing informal traffic to an from boats and for
tracking boats underway.  APRS was designed by a person with 20 years NAVY
experience with tactical radar and data displays and ship-to-ship data
networks on HF.  APRS was designed to operate continuously in the background
and provide connectivity between widely dispersed stations.  It will provide
position and status reporting for all units underway, in near real-time.  I
say near-real-time, because APRS should not be considered a mechanism for
intense keyboard to keyboard conversations; but is ideal for exchanging one-
line messages over an extended time frame without the problems of maintaining
a CONNECTION.  My experience in using APRS on the Naval Academy boats on
summer cruise, is that with boats transmitting their positions and status
once every 15 minutes, there is over a 90% chance that every boat will be
seen at least once every 4 hours, 24 hours a day.

PROPOGATION STATISTICS:  A secondary benefit of the APRS protocol is that it
operates like a poor-man's chirp-sounder.  Since APRS keeps statistics on
the number of packets heard from each station over the last 24 hours, this
display can be used to verify HF connectivity between stations throughout the
day.  It's like a free radio check every 15 minutes everywhere!  After
watching APRS statistics for just a day, or so, the daily variations in
propogation conditions to all stations is visible at a glance.  Further
improvements in connectivity is possible by changing frequency bands during
the solar day.  By saving statistics on each band in a different file, the APRS
user can use this data to optimize his connectivity at any time of day or
location.

WATERWAY NET OPERATION:  There is already a national APRS position reporting
network operating on 7.085 and 10.151 LSB.  (Tune 510 Hz higher if you are
operating an AEA PK-232)  All boaters and Recreational Vehicles are welcome!
To help in tuning up on these frequencies, we have encouraged a few 24 hour
stations to set their alias to TUNE.  Then, if you set your UNPROTO path to
TUNE and use the OPS-PING function, you will get a digipeated packet back
from that station when you are tuned in.  Also try TUNE1, TUNE2, etc, if
there are other alternate permanent stations with better propogation.  Once
you are tuned in, execute the OPS-QUERY command which will request position
reports from everyone on frequency (over the next 2 minutes).  Be patient..
Even without a Query, all stations will transmit their positions once every
15 minutes...

POSITION REPORTING:  Their are several ways to report  your position into the
APRS network.  First, run APRS and both your position and status will be
reported automatically.  Additionally, your station can send and receive
messages to and from other stations on the net.  If you turn off your PC
computer, APRS places your position report in your TNC BeaconText so that
your TNC will continue to report your last known position once every 15
minutes or so.  This Beacon only contains your Position and words to indicate
that your APRS program is not running.  If you want your TNC to automatically
report your position AND some meaningful status information, you can enter
your LAT/LONG and additional comments manually into your TNC BText before
Quitting APRS.

GPS/LORAN AUTOMATIC REPORTING:  With the optional APRS $9 GPS registration
APRS can report your real-time position automatically.  Simply connnect your
navigation device NMEA-0183 output to your second PC COMM port.  APRS will
insert the NMEA position, course and speed automatically into your APRS
position report.  You can also do this without APRS and a laptop, by using
the PACCOM TNC version 3.2 ROM in an HF compatible TNC.  This TNC can be
wired directly to a GPS device and set to send out your position on a set
periodicity.

OBJECT REPORTING:  Since ANY APRS station can report the position of any other
objects, your position can be automatically transmitted into the APRS network
by ANY other station.  Simply make a voice report to a friend or other
waterway net member running APRS.  He can put you on his map so everyone in
the net will see you.  Give your LAT/LONG, course and speed.  You can also
include about 28 characters (36 without Cse/Spd) of additional comments as
desired.   This is a good place to report your Estimated-Time-of-Arrival, etc.
All APRS position reports are time stamped, so that there is no confusion as to
when a report was valid.

DEAD RECKONING:  APRS automatically dead reckons all position reports.  This
causes all stations to see the most realistic positional display.  All
stations that are dead reckoned show up in light blue color and have an
anchor line back to their last actual reported position.  To defeat dead
reckoning and display all stations at their last reported positions, simply
use the CONTROLS-dR command to toggle off dead reckoning.  When moving the
cursor to select stations on the map display be sure to select the actual
position, not the dead reckoned position.  If even new posits are dead-
reckoned, then your PC clock is off.  FILE-SHELL-DOS to re-set your clock!

TRACK HISTORIES:  APRS automatically saves all track histories to disk.  To
reduce redundant data, APRS normally filters out all positions from the same
station that are within 80 yards of each other.  This accounts for the random-
ness of the Selective Availability.  This filter can be turned off, so that
all positions (that are not exact duplicates) will be saved.  Fixed stations
will only be saved once per track history file.  These track histories can be
replayed at any time, either from memory or from file.

WEATHER REPORTING:  All stations on the net can be apprised of unusual weather
conditions by any station placing a weather symbol on the map.  Just like
stations, weather symbols will be dead reckoned between reports.  In this
way APRS is ideal for reporting the movements of hurricanes and tropical
storms.  There are over a dozen different weather symbols for this type of
weather reporting.  Secondly, the $9 APRS WX registration permits automatic
reporting of wind speed, direction, temperature and rainfall using the
ULTIMETER-II home weather station.  All stations with this interface
show up on the maps as a large blue DOT with a line indicating the wind
direction and speed.  Their position report also includes the temperature and
the rainfall.  Similarly, any station can select to use the Weather station
symbol for his station, and can manually enter his wind speed and direction
for display on the net.  See WX.TXT.

SYMBOLS:  In addition to a number of Weather symbols, APRS has two boat
symbols (Sail & Power) plus a Buoy and Lighthouse symbol.  The Buoy can
be colored red or green if it is added as a symbol to a map label.  See
SYMBOLS.txt.

WATERWAY NET OPERATIONS:   Waterway Net participants that are HF packet
capable can routinely report thier posits on the HF APRS nets.  This will
free up the voice net for passing of more voice traffic, and for posits
from non packet stations.  One APRS station can volunteer daily to uplink
the voice position reports into the network from his display by placing
them on his screen as OBJECTS.  Once these reports are being uplinked into
the APRS net, any other APRS station can assume reporting responsibility
for that OBJECT (station) simply by uplinking a later report.  APRS always
overwrites old reports with new ones so that anyone with newer information
can uplink it to everyone.  This enables stations to pass off APRS reporting
responsibilities and keeps the network from being dependent on specific
full time stations.

WATERWAY NET MESSAGE TRAFFIC:  All APRS stations are encouraged to uplink
thier operational status in their one-line BEACON.  Secondly, APRS stations
can send short message lines to any other stations on the net.  These short
messages can be used throughout the day for making schedules for voice
contacts on 7268 without the stations having to listen to the HF freq all
day.  There is also a several line BULLETIN capability for putting out
information to all monitoring stations.  After HF voice operations,
stations that are packet equipped can just turn  the volume down and park
the HF rig on the APRS frequency instead of turning it off.  This will keep
them fully informed and reported without any additional effort.

APRS NET FREQUENCIES:  Until we saturate, all boaters are welcome on the
10.151 LSB APRS National tracking net.  YES, THIS IS IN THE BAND!  See the
esplaination in HF.TXT

OTHER BANDS:  An APRS reporting frequency should also be established on
each of the higher bands as well.  I have not done this, because both of
my HF rigs are dedicated full time to 7085 and 10151.  I would encourage
distant travelers to stake out additional APRS frequencies on 18 and 24
meters.  For just playing around, try 20 meters at 14.100 LSB.  YES this
is listed as the INTERNATIONAL CW BEACON frequency, but again, read HF.TXT
to see that operating LSB on that DIAL freq is actually 1700 to 2100 HZ
away from the actual CW frequency!

NAVAL ACADEMY APRS NET:  During summers only, the Academy operates an
APRS net on 3 Navy HF frequencies for tracking its 20+ boats on summer
cruises.  Serious HF APRS shoreside stations with NAVY credentials might
be useful for assisting the Academy in passing traffic.  If you are
interested, please contact WB4APR.  APRS is also used by the Afloat MARS
net for reporting the positions of all stateside MARS stations on frequency
for passing phone patch traffic.  The US Navy ships, of course, do not
report their positions for security reasons, but use APRS to show who is
listening stateside.  For more info on the Navy MARS APRS afloat net,
contact N1BFQ in New Hampshire.