On Thu, Sep 04, 2008 at 02:10:28PM -0500, we recorded a bogon-computron collision of the <[EMAIL PROTECTED]> flavor, containing: > I'm looking at Hanna and Ike on Xastir, but each has a number of > circles, red, green, yellow around them. Would someone in the know > please give me (and the rest of us land lubbers) the skinny on this, > tell us how all this happens.
Are you asking what the different circles mean? I was able to figure this out by looking at the APRS spec and the source code in db.c --- I was unable to find any documentation of these circles anywhere else. They're the radius of various wind speed ranges as predicted by the NWS. The red circle is the reported (or predicted) radius of hurricane force winds, the green the radius of gale-force winds, and the yellow the radius of tropical storm winds. The packet that contains that information also has information about the true ranges and speeds in the report. Some of the reports are predictions X hours in the future. So HANNA+24h is the prediction for where HANNA will be in 24 hours and how strong it's predicted to be. It's not clear to me that Xastir displays all the information available in the packet. I looked over some of the recent data using the perl APRS decoder (ftp://ftp.eskimo.com/u/a/archer/aprs/Ian_Wade/aprsdecu.tar.gz) and there seems to be a lot more there than Xastir is showing in the Station Info dialog for the object. For example, I just grabbed this packet out of my logs: NHCTCM>APRS,qAS,WXSVR:;[EMAIL PROTECTED]/010/TS/055^065/0989>000&275%090zkIqzhhzzzzz{4FDA0 which the perl aprs decoder shows as: APRS Data Type= Object Object Name= 'HANNA_ato' Object Status= Live Day= 04 Time= 21 hours 00 mins UTC Lat= 24 deg 30.00 min N Long= 73 deg 30.00 min W Icon= Hurricane Overlay= **BAD OVERLAY CHAR 'S' not allowed with this symbol Wind Direction= 315 deg Speed= 010 knots (11.5 mph 18.5 kph 5.1 m/s) Tropical Storm: Sustained Wind Speed= 055 knots (63.3 mph 101.9 kph 28.3 m/ s) Peak Wind Speed= 065 knots (74.8 mph 120.4 kph 33.4 m/s) Central Pressure= 989 mbar/hP Radius of Hurricane Winds= 0 nautical miles (0 miles 0 km) Radius of Tropical Storm Winds= 275 nautical miles (316 miles 509 km) Radius of Whole Gale Winds= 90 nautical miles (104 miles 167 km) There could also be multi-point data hidden in the comment, but I'm not sure. There's additional information here that I'm not sure is captured anywhere in documentation I can find: for example, what's the overlay character signify? Gerry: do you know whether the data after the gale winds data is meant to be a multipoint descriptor, and whether the overlay character is supposed to mean anything in particular? The wxsvr.net web site appears to be gone for good and the documentation that was once there is no longer available. -- Tom Russo KM5VY SAR502 DM64ux http://www.swcp.com/~russo/ Tijeras, NM QRPL#1592 K2#398 SOC#236 AHTB#1 http://kevan.org/brain.cgi?DDTNM "Argue for your limitations and sure enough, they're yours." -- R. Bach _______________________________________________ Xastir mailing list [email protected] http://lists.xastir.org/cgi-bin/mailman/listinfo/xastir
