Ham Radio 2000 #2/Ham Radio 2000 - Volume 2.iso/HAMV2/PACKET/APRS805/README/WX.TXT

Text File | 1997-09-02 | 21.0 KB | 383 lines

WX.txt 7.9.6  USING APRS IN WEATHER AND SKYWARN APPLICATIONS

New in 7.9.6  Now you can add HC/TS winds to the DOT symbol too for
              showing wind radii on predicted positions too
New in 7.9.3  *****  All new WX formats not Backward compatible *****
              WX-GETmetar can load METAR data from a file into P-LIST.
New in 7.8b:  File-Print will log new data to a printer and on the P-LIST,
              Just-Print-WX will print a file or page of all WX data
              Fixes receipt of remote Ultimeter WX data for some units
New in 7.8a:  WX-WINDflow command displays wind vector contours
New in 7.7:   WX-DISP cmd selects WX station map display format

OVERVIEW:  APRS is an ideal tool for reporting weather conditions via
packet.  It is compatible with both human entry as well as automatic
weather station entry of current conditions.  With the optional $14 WX
registration, APRS will accept serial data from the PEET Bros ULTIMETER
or DAVIS home weather stations and automatically insert your wind,
temperature and  optionally rain, humidity and barometric pressure into
your position/weather packet.  You can even mount an ULTIMETER remotely
with only a TNC and Radio, and have it periodically report the remote
weather conditions.  Use the MAPS-OVERLAY-OTHER command to overlay the
WX-APRS.POS file on the map to see all known APRS WX stations..


APRS is idealy suited for SKYWARN with the following features:

 MAP DISPLAY - Shows the location of all reporting stations, their wind
     speed and direction.  Can also show the location of DOZENS of other
     WX symbols or objects... WX-WINDflow displays Wind contours.

 WX SYMBOLS - There are dozens of WX symbols such as TStorms, Hail,
     Tornados, etc in APRS.  Any station may place a storm or other WX
     object on his map, and it will be transmitted to all other stations.
     If a course and speed are given, then it will be automatically dead-
     reckoned on all screens.  Any station can update the location of
     such an object and will become the new reporting station.  This
     prevents duplicate reporting.

 WX WARNINGS - You can even mark large areas with either a rectangle,
     circle, triangle, or lines using the OBJECTS-AREA symbols.

 WEATHER ONLY - The JUST-WX command for a temporary display of only WX
     stations on the map or P-List.  Use the WX-JUST-WX-ALWAYS command
     to lock this feature on and off.  The N-NEXT command cycles through
     each WX station in turn with a circle on the map and displays its
     wx conditions at the top of the screen.  Whenever a new report comes
     in from that station, the weather window is automatically updated.

 WX REPORTS - Station weather conditions can be manually entered with
     the WX-ENTER command or automatically using the optional APRS WX
     registration and home WX station.  These reports are typically
     broadcast every 9 minutes or on demand in respond to a WX-QUERY.

 TROPICAL STORM WINDS - For tropical storms a special COMMENT format
     will cause APRS to color huricanes red, tropical storms yellow
     and depressions blue. It will also show the radius of the winds with
     colored circles.  These wind radii are offset in the direction of
     the danger quadrant proportional to the storm speed of advance.

     DDHHMM/LAT/LONG@CSE/SPD/TS/www^GGG/ppp>RRR&rrr
                    |        |   |   |   |   |   * - - Radius of TS wnds
                    |        |   |   |   |   * - - - - Radius of HC wnds
                    |        |   |   |   * - - - - - - Cenral Pressure
                    |        |   |   * - - - - - - - - Gusts
                    |        |   * - - - - - - - - - - Sustained winds
                    |        * - - - - - - - - - - - - HC, TS, or TD
                    *- - - - - - - - - - - - - - - - - Works on @ and /

 DEAD RECKONING -  APRS dead-reckons moving objects, so the symbol on the
 map is presented where it SHOULD be, NOT where it was when first reported.
 To hook one of these objects on the map, you must hook the little gray
 circle which marks the position of the actual report, and not the symbol
 itself.  After two hours with no update, the symbol fades to dark gray.

 NWS STATION PLOTTING - Hit MAPS-OVERLAYS-NWS to see all NWS Sites

 METAR BULLETINS - Suggested by KD4UYR in FLorida, this feature parses
     NWS METAR bulletins and plots the WX data on the map.


 AUTO-HURICANE TRACKING - At the suggestion of KR4US I wrote NWSPARSE.bas
     which will parse incoming NWS bulletins on one COM port, and output
     APRS storm symbols and tracks via a TNC on the other COM port.
     Using an old PC, this system can automatically inject WX storms
     into APRS nets!  It needs more work and additional parsing.

 WX-DISPLAY - You may select to have the WX conditions displayed
     by each WX station instead of the callsign.  There are 3 formats.
           WX-DISP-TIME shows the TIME
           WX-DISP-TEMP shows Temperature
           WX-DISP-BARO SHows Baro and rain
           WX-DISP-WIND Shows winds

 OPERATOR MESSAGES - The Point-to-point message capability can be used
     for operator to operator messages and alerts.  With FILE-PRINT
     enabled, these messages and WX reports can be scrolled to the printer.

 COMMENTS   -  Transmitted along with each position report, there is a
     short comment field which can be used to report weather conditions,
     station status, intentions or other broadcast type information.


    In addition to weather data included in position reports, the station
STATUS packet is also available for broadcasting additional info.  These
STATUS packets can be reviewed on the LATEST display.  The APRS BULLETIN
feature is very powerful as an alerting mechanism to all stations on the
net.  Even non-packet voice stations making a weather report can be placed
on the map (like an object) by another APRS packet operator.  His station
will appear similar to any other APRS weather station, except that his
report will include a marker indicating that he was manually placed on
the map by another operator.


NATIONAL WEATHER SERVICE HOURLY METAR BULLETINS

     Based on work by KD4UYR in Clearwater FL, the MAPS-OVERLAY-NWS command
searches the NWSposns.POS file and temporarily displays all NWS stations
within the boundaries of the current APRS map display (up to 250 miles).
You are given the option of a one-time map overlay or to add the sites to
your P-LIST.

     The WX-GET-METAR command is used for loading a file of NWS METAR
reports.  This file can be obtained from most of the commercial data
servers or some BBS's, or on the internet at wx.atmos.uiuc.edu.  APRS
will scan the NWS METAR file looking for each station that you have
on your APRS P-LIST.  For each match, it will parse the Winds, temperature,
dew point and barometric pressure onto the P-list.  It takes the remainder
of the report and places it on the L-list.  The time of the entries in the
P and L-list will be the time of the NWS report (in local time).  The date
is assumed to be the current date.

Once the data is loaded, you can uplink selected stations to the APRS net
as desired.  Be considerate, though, and not overload the channel.
Once everyone on the net sees the reports, the uplinking station should
consider Quitting the uplink in order to reduce QRM.

DEMONSTRATION:  To see how APRS works in a SKYWARN or other reporting net,
load the backup file SKYWARN.BK using the FILES-LOAD command.   To
demonstrate the NWS capability, center your map on Illinois at the 128
mile range, enter the MAP-OVERLAY-NWS command and select the Add option
to add them to your P-List.  Next, enter the WX-GETmetar command to load
the sample METAR data file.  Look at the P and L-lists to see what is
going on...

METRIC MEASUREMENTS:  You may select wind speed in KPH and temperature in
Celsius by toggling the WX-METRIC command.  This will force the WX display
at the top of the screen to display metric and will cause the manual WX
entry values to be accepted in Metric.  You can make this permanent, by
saving a CONFIG file.  The on-air APRS WX protocols, however, still
will be in MPH and F.  Also, the ALARMS are compared to MPH and F values.

WX ALARMS:  If a WX report comes in that exceeds your alarm values, the
station is plotted in RED and an ALARM sounds.  The alarms are WIND, TEMP,
and RAIN.  These settings can be used to warn of the passing of a warm or
a cold front.  Use APRS and these alarms to make an almost un-attended
SKYWARN network!  Install an APRS computer at the NWS site, and let the
NWS operators set the alarm levels.  Then without transmitting a single
packet (there is rarely a licensed HAM on the premises) the APRS screen
will show SKYWARN data and where the alarm conditions are!

CLEARING ALARMS:  When an alarm occurs, the station is drawn in RED and
the map is re-drawn to center on that station.  Also, the station is
marked on the P-list with the ALARM marker.  TO clear the alarm, simply
hook the station on the map, and then UNhook it (hit ENTER twice), or
use the WX-ALARMS-CLEAR command.  To clear the A on the P-list, hook the
station and hit the A key.  Normally, the ALARM on the P-list will only
sound if that station MOVES.  Since a WX station should not move, there
is really no problem in leaving the A on the Plist until convenient to
remove it.

WEATHER WARNINGS AND WATCH BOXES:  You can use the OBJ-AREA-LINE command
to draw a box plus-or-minus X miles from a line between points A and B.
The line and width are perfect for WATCH and WARNING boxes.  If baseline
lengths longer than 400 miles are needed you must combine two or more
boxes.  Use the normal OBJ-AREA-LINE command and indicate the +/- offset
of the sidelines in a 3 digit number of Miles enclosed in braces {075}
anywhere in the COMMENTS field.

HOME WEATHER STATION INTERFACE:  With the optional $14 WX registration,
APRS inserts the ULTIMETER or DAVIS conditions in your position report
for unattended weather reporting.  ULTIMETERS that output data with a *
output wind in MPH and those with a # in KPH.  APRS detects the
difference and does the conversion.  Also APRS averages the wind value
over the last 4 samples.  Thats why the display UPDATE period is set to
15 seconds, so that the resulting wind speed transmitted represents a
1 minute average.

RAIN VALUES:  Each WX instrument has one or more rain counters which are
incremented every 0.1 or 0.01 inch.  APRS asks you which gage you have
and converts both to 0.01 inches on the air.  Since rain counts have no
meaning without knowing when they were last reset, APRS only compares
the difference in rain for the last 60 minutes (rXXX) and the last 24
hours (pXXX) (P for Precipitation).  A reading of r123 means 1.23 inches
fell in the last hour.  After 60 minutes, this value will return to zero.
A reading of p164 means 1.64 inches have fallen since the same hour
yesterday.  For REMOTE ULTIMETERS where there is only a TNC and no PC,
the P value means rain since MIDNIGHT and an uppercase Pxxx is used.
Also since there is no RAIN per hour value, that field is replaced with
the raw rain counter #xxxx.

FORMATS:  The following formats are the way that APRS re-formats the data
from the attached WX unit and transmits the data on the air.  For remote
Ultimters, where there is no PC, and the TNC is just transmitting the raw
Ultimeter format, then these formats represent the way that APRS parses and
displays the received data on the P-LIST.

   _CSE/SPDtXXXrXXXpXXXgXXXdU-II        Original U-II auto
   _CSE/SPDtXXX#XXXU2r                  Original U-II remote
   _CSE/SPDtXXXrXXXpXXXbXXXXhXXgXXXdDvs  Davis WX station
   _CSE/SPDtXXXrXXXpXXXbXXXXhXXgXXXdU2k  U-500/2000 with APRS
   _CSE/SPDtXXXPXXXbXXXXhXXgXXXU2kr      Remote Ultimeter Logger
   _CSE/SPDtXXX#XXXbXXXXhXXgXXXUpkm      Remote Ultimeter Pkt Mode

   _CSE/SPDgXXXtXXXrXXXpXXXPXXXhXXbXXXXX%type NEW FORMAT APRS793 June 97
                                              NOT BACKWARD COMPATIBLE

Where:        CSE/SPD is wind direction and sustained 1 minute speed
              t is in degrees F
              r is Rain per last 60 minutes
              p is precipitation per last 24 hours (sliding 24 hour window)
              P is precip per last 24 hours since midnight
              s is snow
              b is Baro in tenths of a mb
              h is humidity in percent.  00=100
              g is Gust (peak winds in last 5 minutes)
              # is the raw rain counter for remote WX stations
                   See notes on remotes below
              % shows software type d=Dos, m=Mac, w=Win, etc
              type shows type of WX instrument


With the WX interface enabled, the normal APRS decaying of position/wx
reports still holds as long as nothing changes (except the wind).  This
way, redundant WX reports do not cloud the channel.  If any value,
Position, temperature, rain, barometric pressure, or comments change,
then the periodicity is reset to the value set in the alt-SETUP-POSrate
command.  Since the wind is the most changing parameter, the WX-WIND
command can be used to set a Wind threshold.  Whenever the wind is above
that threshold, the reporting period is also reset to the POSrate value.
Nominally, you might want to set the POSrate value to about 4 minutes or
so.  This way, during changing WX conditions, or wind above your
threshold, the WX is reported every 4 minutes.  Otherwise, the period
rapidly decays back to the maximum APRS delay period (default is 20
minutes).  For a weather station, you might want to change this MaxPeriod
to maybe 10 minutes or so.  Use a text editor to change this value in
your CFIGxxx.APR file.  There it is expressed in seconds.  Of course, a
WX/position report will be transmitted by the APRS station at anytime,
in response to an APRS or WX query.

ULTIMETER INTERFACE CABLE:  Peet Bros sells an interface cable with a
DB-25 connector to RJ-11.  (Note, this is a DB-25, not a DB-9).  Since
the U-II has no negative supply, a 5 K pulldown resistor is added to the
DB-25 connector between Pins 2 and 3.  This uses the -5 or -12 volts on
your TXD line to bias the RXD line.  When I plugged in a standard phone
line connector to the U-II serial data output (unmarked connector on
their junction box, or side of the Display unit), I found the data output
on the green while using the black wire as ground.  If your connector was
crimped on backwards, red is data and yellow is ground.  The Peet Bros
cable includes transient protection and RF filtering to protect your
computer as well as providing the bias resistor.   Remember, the
annemometer is like an antenna, high in the air.  It can radiate RFI and
take lightening charges... The U-2000 is directly RS-232 and needs no
pull down resistor.  Be sure the U-500/2000 is in DATA-LOGGER mode.

DAVIS INTERFACE:  You must have the DAVIS Weather Link serial interface
option before your Davis station will output serial data.  Simply connect
their connector to your PC. You MUST use the APRS alt-SETUP-OTHER-AGL
command to set your average ground level.  This converts your baramoter
readings to their equivalent value at sea level...  Your objective is to
find an exact AGL that will result in your BARO readings matching the
readings on your instrument or local NWS.  THis AGL will probably NOT be
your true AGL.

SAVE A COMM PORT!  You can use a simple 89 cent switch to allow other
devices to share a single COMM port with your WX station.  Since the WX
stations only use ONE pin and GROUND, simply add them to your MODEM
cable with a simple SPDT switch as follows:

       ULTIMETER-II   >---------*--------*  sw1
                                |        <----*--------------> RXD
       MODEM   }      >------------------*
         or    }                |
       other   }                *-----/\/\/\/\-------*
       serial  }                        5.6k         |
       device  }      <------------------------------*-------< TXD
               }      * * * -----------------------------* * * other pins
               }      *--------------------------------------* GND

Actually, you can wire this to any serial device that you do NOT use while
running APRS.  I chose my MODEM that is on COM2.  Note the series resistor
as mentioned in the text to provide the -V pull-down for the U-II output.

REMOTE ULTIMETER OPERATION:  Only the Ultimeters from Peet Bros can be used
as remote WX stations (using only the WX station, a TNC and a radio).  This
is because they output continuous data withing needing a PC to interrogate
it periodicaly.  There are two ways to time the transmission of this data
for the packet channel depeneding on what Ultimeter you are using.  We call
these PACKET mode or DATA LOGGER mode:

DATA LOGGER MODE (GPS mode):

  U-II - These units output 14 bytes continuously beginnning with * or #
  U-2000 (old) - These units output 44,48,or 52 bytes beginning with !!

For the DATA LOGGER mode, the TNC must do the scheduling of packets just
like the TNC does for continuous GPS data.  That is why this mode is often
called the GPS mode even though GPS has nothing to do withe Weather.  You
must program your TNC to think that the WX data is GPS data.  Simply
program the stand-alone-TNC to recognize the #, * or !! instead of the
usual $GPRMC data typically used for GPS.  Then set the timing for each
transmission to be about once every 5 minutes.  Be sure to SET ECHO off if
your ULTIMETER-II uses a resistor on the TXD line to bias the RXD line!
(Otherwise you will echo all heard packets back onto the channel!  KD4GOE
figured that one out!).

PACKET MODE :
  U-500 - Outputs 44,48,or 52 bytes beginning with $ULTW

This mode was designed for APRS packet since the WX unit only outputs
a single data line every 5 minutes.  Since it is already timed to once
every 5 minutes, all the TNC has to do is be in UI CONVERSE mode and it
will send the packet.  Be sure to use a TNC that can be configured to
power-up in UI-CONVERSE.  Try UIMODE or PMode-CONV depending on your
TNC.  ALso you must set LFIgnore to ON so that the LF after the CR is
not transmitted..  Since the Kantronics TNC's do not have LFIGNORE,
you must set SENDPAC to $0A (linefeed) and set CR off!  If there are
dozens of REMOTE U-500's, hopefully their clocks are staggered enough
that they wont all transmit at EXACTLY the same time.

CAUTION:  Only U-500's and only U-2000's manufactured after April 97
should be used in packet mode.  U-2000's prior to that date will not
show wind in the packet mode.


WX POSITION:  In both cases, you must put the unit's POSIT in the BText
using the "_" WX symbol.  This way the TNC transmits two packets, one
is a BText WX posit with no WX data, and the other is raw WX data with
no posit!  APRS cannot display the WX on the map until it has received
a WX posit beacon.  So, set the beacon to go about once every 20 minutes.
Once the posit is received it will be displayed as a Blue dot unless the
site is also acting as a WIDE-RELAY digipeater, and it will show GREEN if
the delimiter between the LAT/LONG is set to a backslash instead of the
usual forward slash.

WX LOGGING:  Use the WX-LOG command to turn WX-LOGging on and off.  It will
show on the control panel when on.  If ON, then on-air reports are saved
when received every 10 minutes or so, and your own report will be saved at
the rate set by the Set-Pos-Rate command.

AUTOWX.EXE:  This is a program written by Les, N5KOA to also interface
the Ultimeter to a TNC with a PC and send APRS data.  I have not used nor
tried this program.  Contact Les Blalock, N5KOA, 1711 Pagewood, Odessa,
TX  79761.  [phone] day, 332-1942 fax,   367-0408 eve or on the
Internet [e-mail]

DIRECTION FINDING:  Since your station can only send one position report,
If you use the BEAMHEADING command to enter a beam heading on a Fox or
Jammer, then your WX station is disabled.  To restore your WX station,
restart the program.

1995 prices:

$$$  The ULTIMETER-II is available from PEET Bros 1-800-USA-PEET
     (872-7338) for $199 plus $20 for their Serial interface cable and
     $68 for the optional rain guage (self emptying, 0.1 inches) plus
     shipping of $8.75.  (For APRS, their $69 software is not required
     but it is a good package for doing the usual home WX logging and
     analysis)  See ads in  QST, CQ, Popular Mechanics, etc.

     The ULTIMETER-2000 is also available for $379 and includes
     Barometric pressure.  Outside Humidity/Temp sensor is $110.

     The higher sensitivity .01 rain gauge is $90.  And a wireless
     remote rain gauge is $139.                      afs

     The ULTIMETER-500 $239. is the same as the U-2000 but without the
     barometer and humidity.

     The DAVIS Weather Monitor II is available for about $395.  Rain
     gage is $75, and outdoor Humidity/Temp sensor is $125.  For APRS
     you will also need their WeatherLink for $165.