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I am programming a small planning application for some friends and me. The application imports weather data from other weather engines (REX and FSGRW so far) and displays it on a map. Because several of my friends are using Active Sky, they asked me, if I can read these files as well. The problem is, that I can't find any documentation about this file format and that I don't own Active Sky (just REX). Therefore I cannot open a ticket or thread in the official Hifi forum. That's why I am writing here.

I have a copy of the file current_wx_snapshot.txt and analyzed its structure. Stations, METAR and TAF are easy to parse, but I found no information about the format of upper wind data. Upper wind is stored in a string like the following:

087,008,11.1 / 276,001,08.4 / 279,003,05.6 / 299,006,-03.9 / 333,010,-15.5 / 038,022,-27.8 / 042,071,-38.3 / 040,078,-48.6 / 029,071,-58.8

The string consists of 9 blocks separated by "/". Each block consists of 3 numbers: Wind direction, wind speed and temperature. What I am missing is the information about the altitude. I assume that each block represents a well defined altitude, but I don't know which one.

By importing this file into PFPX, I found out, that block #9 corresponds to FL400 and #7 to FL300. But I can't figure out the correct altitude for the other 7 blocks. Pressure Surface (like in REX) doesn't match either (and raw GRIB data has just 8 levels instead of 9).

Is there somebody who knows any details about this file format?


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Hi Martin,

The ActtiveSky aloft altitudes (in ft) are: 3000, 6000, 9000, 12000, 18000, 24000, 30000, 34000, 39000, 44000, 49000, 56000
That's 12 altitudes, but I've only ever seen the first 9 of them in the current_wx_snaphot.txt file.


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