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Export Formats

Balloon Track exports files in several formats.

If you desire some type of easy text file export capability for a program you regularly use, you can suggest it to me by sending along some directions on how the files are built and some example files I can play with to test the program. If it isn't too hard, I'll probably be willing to add some more export types.

These are the Export Formats. Click on them for more information.

• APRS

• Comma Delimited

• Flight Prediction

• Google Earth KML File

• GPS File

• GPS Visualizer (website)

• Ozi Explorer

• Street Atlas

• Topo50

• UI-View Overlay

APRS

BT can export several types of APRS (Automatic Packet/Position Reporting Software) files. The program will suggest a filename of whatever you enter as the callsign with a txt file extension, in the case illustrated below, N0KKZ-3.TXT.

Enter a callsign. Most APRS programs will work with Aliases so you could just enter Balloon or something similar, it may not be necessary to follow Amateur Radio Call sign formats. But, if the track doesn't show up on your APRS program, try using a call sign.

Select an Icon. If you click on balloon the default upper case "O" (oh) will be used. For a list of all "approved" icon designations, go to www.tapr.org and download the DOS version of APRS by the creator of this system, Bob Bruninga, WB4APR. A file in this zip will indicate what type of icons are associated with which ASCII characters.

Enter a day of the month (numeric, 1 to 31) and and hour and minute. Many APRS programs allow for data to be "decayed" off the display by checking their "age". So, this day and time thing might be necessary depending on what options you have set for age filtering.

Select (in the lower left corner)  "Course/Speed/Altitude APRS" or "Lat/Long Only". 

Check "String only o APRS headers" if you wish to omit the addressing information of a packet.

Click OK, and BT will export an APRS formatted file. The time stamps for each simulated packet will be accurately related to the prediction run currently active in the program by adding the elapsed time to the expected launch time.

I regularly use this format now for each flight. I run the prediction, export this file and then load it into my tracking software. As the flight progresses, I can compare the predicted track with the actual track and get some idea of where the balloon might actually land. 

I also export several different Street Atlas files with different labels in each. That way, I can quickly overlay the expected altitudes along the track and further compare progress of a balloon. Or perhaps elapsed time. It all helps in trying to stay one jump ahead of the DF teams and predict a likely touchdown location during the flight.

String Formats

APRS Standard String

N0KKZ-3>APRS:@093216h3951.64N/10429.66WO135/102/A=040885

This string has a timestamp breaks out as:

• 09:32:16 UTC time
• 39° 51.64' Latitude
• 104° 29.66' Longitude
• The "O" following W in longitude indicates a balloon icon
• 135° true course
• 102 Knots
• 40,885 feet above sea level altitude

Aprs Latitude Longitude Only

N0KKZ-3>APRS:!3951.64N/10429.66WO

The break out is simply:

• 39° 51.64' Latitude
• 104° 29.66' Longitude

APRS String Only

A new format (slightly).

@093216h3951.64N/10429.66WO135/102/A=040885

It is the same format as above but the header information, N0KKZ-3>APRS:, is omitted. This means you can transmit the exported file via TNC in unproto mode "K", and your tnc will add your callsign and unproto routing and thus mimic a balloon flight. EOSS is about to start using this method to transmit predictions through an airborne balloon to the tracking and recovery teams in the field.

Comma Delimited (csv)

The most universal format is the comma delimited text file. When selecting this option, BT will suggest the name of your data file but replace the file extension with .CSV. This file type is recognized by Excel and can be imported into that program with ease.

The program exports, in this order, the following values.

• Time (as calculated from the values set for the Expected Launch Time on the Setup Screen)

• Elapsed Time

• Altitude (ft.)

• Bearing

• Range (mi.)

• Elevation

• Climb/Descent Rate (fpm)

• Latitude

• Longitude

• Footprint Radius (mi.)

• GridX (mi.)

• GridY (mi.)

The measurement units change to meters and kilometers in metric operation.

Flight Prediction

A plain text file (human readable).

Things to note:

The date and time that this prediction was made is on the left side of the header.

The name of the data file used to generate the prediction is in the header, in the sample below, "NAM-12_06_10_21_1500Z.dat" This filename tells you several things.

The model used is the NAM-12 model. The program decifers this by reading the raw data file's filename as imported from and named when downloaded. This is a bit clunky. You have to manually enter in a filename when you download a winds aloft file. The rule is, whatever comes at the front of the filename and is separated by the rest of the filename by either an underscore (_) or a dot (.) will be used as the model name. In order for this to work you need to check "User Source Filename" on the "[Folders/Files] tab of the setup screen. If you don't want to do this, then uncheck it and the program will revert to it's old way of generating filenames. The date in the filename is the date of the expected flight. The program can derive this information by looking inside the downloaded winds aloft file (usually).

In the sample below, the program was set to output predictions using the EOSS grid. And so, the output on all screens of the program and its printed output use that convention. Setting the output to lat/long would be more conventional.

Here is the sample.

Balloon Track for Windows                                Version 1.9.5
__________________________________________________________________________

                              Flight Prediction

Sunday, December 17, 2006         EOSS-114       NAM-12_06_10_21_1500Z.dat
2:19:26 PM                         Windsor                    wbaltrak.ini
__________________________________________________________________________

Winds DataFile
-----------------------
        Station: DEN
           Date: 21-Oct-06 15:00
DataFile Status: Intact 
 Intact Records: 20 
Corrupt Records: 0 

Grid Placement Data
-----------------------
 Reference Site: Int 71-14 West
       Latitude: 40.61025° lat.   
      Longitude: -103.6769° long.
       X_Offset: 45.00
       Y_Offset: 35.00
Grid Origin
       Latitude: 40.10335° lat.   
      Longitude: -104.53537° long.

Launch Site - Windsor
-----------------------
   Launch Point: 40.47367° lat.   -104.96233° long.
           Grid: X=-22.43 Y=25.57
    Ascent Rate: 1100 feet per minute
   Descent Rate: 950 feet per minute
       Altitude: 4931 feet

Maximums Enroute
-----------------------
Distance to LOS: 403.7 Mi.
  Maximum Range: 85.3 Mi.
  Maximum Winds: 87.0 mph from 284° at 38,868 feet altitude

Burst Data
-----------------------
    Burst Point: 40.10047° lat.  -104.01395° long.
           Grid: X=27.5 Y=-.2
     Burst Time: 81.9 minutes
 Burst Altitude: 95,000 feet
  Burst Bearing: 117.0°
    Burst Range: 56.2 Mi.

Predicted Landing Site
-----------------------
  Landing Point: 39.88599° lat.  -103.54002° long.
           Grid: X=52.7 Y=-15.0
       Altitude: 5000 feet
    Flight Time: 123 Minutes
        Bearing: 117.9° True
          Range: 85.3 Mi.
__________________________________________________________________________

                Bear Rng  EL. Vertical                      Dist. Bearing Range VOR
 Time      Alt   Deg  Mi. Deg   FPM    GridX -Mi.- GridY    to LOS  Mag    NM   ID
-----------------------------------------------------------------------------------------
     < 1  4981  193    1  54   1100   -22.43     25.56      10     253    19   GLL
     < 1  5699  193    1  54   1100   -22.45     25.47      37     253    19   GLL
       1  6503  195    1  54   1100   -22.48     25.36      53     252    19   GLL
       2  7326  193    1  52   1100   -22.51     25.23      66     252    19   GLL
       3  8169  184    1  45   1100   -22.47     24.96      77     251    19   GLL
       4  9035  176    1  40   1100   -22.37     24.65      86     250    19   GLL
       5  9925  170    1  36   1100   -22.21     24.31      95     249    19   GLL
       6 11778  164    2  32   1100   -21.86     23.54     111     247    19   GLL
       8 13750  161    3  28   1100   -21.40     22.64     126     245    19   GLL
      10 15863  159    4  26   1100   -20.95     21.69     141     242    18   GLL
      12 18133  158    5  26   1100   -20.50     20.72     155     239    18   GLL
      14 20600  156    6  25   1100   -19.85     19.72     168     236    18   GLL
      17 23314  152    8  24   1100   -18.82     18.60     182     232    18   GLL
      19 26345  147   10  22   1100   -17.06     17.37     197     226    17   GLL
      23 29820  140   12  21   1100   -14.44     16.14     212     218    16   GLL
      26 33914  131   16  19   1100   -10.27     14.93     229     205    14   GLL
      31 38868  124   22  16   1100    -4.29     13.19     248     183    13   GLL
      37 45118  119   30  14   1100     3.69     11.16     270     154    15   GLL
      44 53507  116   39  13   1100    13.09      8.40     296     134    21   GLL
      57 67480  115   49  13   1100    22.29      4.60     336     125    29   GLL
      82 95000  117   56  16   1100    27.54     -0.20     404      55    31   DVV
      88 67480  117   58  11   4251    28.90     -1.44     336      58    31   DVV
      93 53507  117   62   8   3045    32.22     -2.82     296      62    34   DVV
      96 45118  116   66   6   2491    36.37     -4.07     269     249    31   AKO
      99 38868  116   70   5   2145    40.46     -5.14     248     245    28   AKO
     102 33914  115   73   4   1906    43.92     -6.18     229     242    26   AKO
     104 29820  115   76   3   1734    46.56     -6.98     212     238    24   AKO
     106 26345  115   78   2   1605    48.36     -7.84     197     235    23   AKO
     108 23314  115   80   2   1503    49.64     -8.77     182     232    22   AKO
     110 20600  115   81   2   1418    50.45     -9.64     168     229    22   AKO
     112 18133  116   82   1   1347    50.97    -10.47     154     227    22   AKO
     114 15863  116   82   1   1286    51.36    -11.30     140     300    22   TXC
     116 13750  117   83   1   1233    51.76    -12.16     126     299    21   TXC
     117 11778  117   84   1   1186    52.19    -13.00     111     298    20   TXC
     119  9925  117   85   1   1144    52.53    -13.74      94     297    20   TXC
     120  9035  117   85  -1   1124    52.68    -14.08      85     297    19   TXC
     120  8169  118   85  -1   1106    52.78    -14.39      76     296    19   TXC
     121  7326  118   85  -1   1088    52.82    -14.66      65     296    19   TXC
     122  6503  118   85  -1   1071    52.79    -14.80      52     296    19   TXC
     123  5699  118   85  -1   1055    52.76    -14.91      36     295    19   TXC
     123  5000  118   85  -1   1041    52.73    -15.01       1     295    19   TXC


GLL = Gill CO, DVV = Mile Hi CO, AKO = Akron CO, TXC = Thurman CO

Google Earth KML File

See the page detailing this capability for more information.

GPS File

NMEA Formatted Strings

For a fairly extensive description of the NMEA strings see the NMEA FAQ on the EOSS Web site.

Within our group we need test files to develop various systems. I decided to create this export routine to help with that. However, many APRS programs can read GPS data and you might find this of interest in some way that APRS exports does not fulfill. The "GPSPO" address in these exported packets should flag APRS programs to read them.

The program will export 4 types of GPS strings. $GPGGA, $GPRMC, $GPGSA and Garmin's proprietary $PGRMV. You can either export these strings in one of two formats.

As Packet formatted strings as shown in the break out examples below with the "Packet Callsign" and an unproto address of GPSPO. This format should be importable by most APRS programs, and might be of use in some GPS utility programs.

Or,  you can export the strings by themselves as:

$GPGGA,164733,4030.621,N,10423.588,W,1,08,1.0,17640.3,M,46.9,M,,*52

You can select any combination of strings, however, you MUST select one of the $GPGGA, $GPRMC, or $PGRMV strings. Omitting all will cause the program to show an error message. There are 6 different $GPGSA strings. Each has slightly different settings, including one that indicates a 2D lock in Manual mode. These strings are added to the export file at random. I primarily added them to offer a changing flag that indicates a GPS receiver is in 3d/2d mode. Our group needed test files with this string to determine the reliability of the altitude readouts while coding the firmware for the controllers.

Changing any values on this form will force them to be written to the INI file and used in subsequent program runs.

Perhaps some APRS programs can calculate magnetic degree solutions. If so, you can enter the offset here and indicate whether it is east or west. It will be included in the $GPRMC string.

Many of the values are fudged since this isn't data from a GPS receiver. I'll note all fields below, but generally speaking all tracking information you need should be available and accurate.

$GPGGA

N0KKZ-3>GPSPO:$GPGGA,164733,4030.621,N,10423.588,W,1,08,1.0,17640.3,M,46.9,M,,*52

This string breaks out as:

• 16:47:33 UTC time
• 40° 30.621' North Latitude
• 104° 23.588' West Longitude
• 1 = fix quality and represents a GPS Fix (BT Fudge)
• 08 = Number of satellites tracked (BT Fudge)
• 1.0 = Horizontal dilution of position (BT Fudge)
• 17640.3 = Altitude in meters
• 46.9,M = Height of geoid (mean sea level) above WGS84 ellipsoid (BT Fudge)
• (empty field) = time in seconds since last DGPS update (BT Fudge)
• (empty field) = DGPS station ID number (BT Fudge)
• *52 = mandatory checksum (this is calculated in case any programs verify the checksum)

$GPRMC

N0KKZ-3>GPSPO:$GPRMC,164733,A,4030.621,N,10423.588,W,018.4,084.0,230101,010.5,E*67

The only fudge factor here is the receiver warning. Balloon Track calculates all other values. The Date of fix is your system date.

This string breaks out as:

• 16:47:33 UTC time
• A = Navigation receiver warning A = OK, V = warning (BT Fudge)
• 40° 30.621' North Latitude
• 104° 23.588' West Longitude
• 018.4 = Speed over ground, Knots
• 084.0 = Course Made Good, True
• 230101 = Date of fix 23 January 2001
• 010.5,E = Magnetic variation 10.5 deg East
• *67 = mandatory checksum (this is calculated in case any programs verify the checksum)

$GPGSA

N0KKZ-3>GPSPO:$GPGSA,A,3,04,05,,09,12,,,24,,,,,2.5,1.3,2.1*39

Stored within the code are 6 different GSA strings. They represent different satellites used in the "fix" and different modes of operation (manual/automatic, 2D/3D). The program selects one string at random and reproduces it 3 times associating it with the "real" $GPGGA and $GPRMC strings. After using a string 3 times, the program selects another GSA string at random. We at EOSS are only interested in the field that represents the mode of the receiver ( the first 3 indicates the receiver is in 3D mode). For details about this string see the NMEA FAQ.

$PGRMV

N0KKZ-3>GPSPO:$PGRMV,6.5,9.3,5.1*7D

This string contains data in a Garmin proprietary format.

The string breaks out as:

• 6.5 meters per second heading east
• 9.3 meters per second heading north
• 5.1 meters per second ascending
• *7D = mandatory checksum (this is calculated in case any programs verify the checksum)

Negative numbers reverse direction for instance:

N0KKZ-3>GPSPO:$PGRMV,-6.5,-9.3,-5.1*7D

This string breaks out as:

• 6.5 meters per second heading west
• 9.3 meters per second heading south
• 5.1 meters per second descending
• *7D = checksum (it's wrong in this example because I added negative signs to the string)

GPS Visualizer File

The website www.gpsvisualizer.com can take this comma delimited file and create online maps. The actual data file looks like this:

"Time UTC","Latitude","Longitude","Altitude","Speed","Course"
"14:30:02",40.4735737932551,-104.962359197999,1518.20880231982,,193,"Launch - Windsor"

But broken out into columns, a typical prediction might look like this:

Ozi Explorer

I don't have this program so, I can't personally speak to its usefulness. But, it sounds quite nice. Folks outside of Street Atlas territory needed something and this program will work virtually anywhere. As I understand it, you can scan in any maps you want, register them (lat/long at several locations in the map and projection type) and the program will then overlay GPS type data (APRS) on the map.

The WPT file contains ONLY the Launch, Burst and Landing points. The Track file "PLT" contains a full track of the flight. If you are familiar with Ozi Explorer and want to use this export capability, I'm sure you'll be more expert in it than I am. I merely read their help file and followed their directions on how to build this type of file. It has been tested by some folks in Argentina and they seem happy so far (reading this Luis?)

Street Atlas File

BT can export to a Street Atlas Latitude/Longitude file format. This format has some serious limitations but it is still useful. BT will suggest the filename latlong.txt but, you can change it to anything you like (of course).

It is pretty straight forward. Select the type of icon you want to represent each data point and the size of the icon to be displayed in Street Atlas. 

Selecting different colors for the ascent and descent phases of the flight helps significantly.

By selecting one of the Plot labels you can add, Altitude, Elapsed Time, Bearing Range and Elevation, and the footprint radius. These are NOT exclusive. You can select all or any combination. But the labels to get too wordy if you include too much, and any labels usually clutter up the track. 

I'll probably add the Grid X, Y coordinate system (for every reported altitude) in 1.6.6 but forgot to get to it this time out. However, the important launch, burst and landing X, Y's are in there if you select, counter intuitively I'll admit, nothing for the labels.

If you select NO labels, then the name of the Launch Point is included as a label for the first data point, the Burst is labeled as such and the altitude of burst is given and the landing is labeled with "Touchdown" and the range and bearing to that location. If you are running the program in Grid mode, the grid x, y coordinates for each of these three points is also given.

Topo50

A European group asked for this export capability to interact with their mapping programs.

[Symbol 1]
Typ=3
Art=1
Col=8
Zoom=2
Size=103
Area=1
Punkte=41
XKoord0=-104.962359197999
YKoord0=40.4735737932551
XKoord1=-104.962778472039
YKoord1=40.4721922635878
XKoord2=-104.963388655554
YKoord2=40.470673937462
XKoord3=-104.963842132601
YKoord3=40.468717278594
XKoord4=-104.963131359982
YKoord4=40.4648700567224
XKoord5=-104.9610988436
YKoord5=40.460378954332
XKoord6=-104.958176020755
YKoord6=40.4553835230459
XKoord7=-104.951402411962
YKoord7=40.4443271095767
XKoord8=-104.942627956517
YKoord8=40.431214520048
XKoord9=-104.933820559303
YKoord9=40.4174582261871
XKoord10=-104.925255974669
YKoord10=40.4034598027936
XKoord11=-104.912875432566
YKoord11=40.3889251580993
XKoord12=-104.893162516874
YKoord12=40.3728003400844
XKoord13=-104.859579495639
YKoord13=40.3548459515807
XKoord14=-104.809743973278
YKoord14=40.3370677406251
XKoord15=-104.730496315885
YKoord15=40.3196019044947
XKoord16=-104.616859660593
YKoord16=40.2944465335704
XKoord17=-104.465286106688
YKoord17=40.2650295404888
XKoord18=-104.287120729346
YKoord18=40.2250573892692
XKoord19=-104.112810651065
YKoord19=40.1699256869712
XKoord20=-104.013953514112
YKoord20=40.1004735574736
XKoord21=-103.988405796172
YKoord21=40.0824883209984
XKoord22=-103.925623762414
YKoord22=40.0624407670644
XKoord23=-103.847297891922
YKoord23=40.0444584530083
XKoord24=-103.77001107189
YKoord24=40.0288837333717
XKoord25=-103.704907730592
YKoord25=40.0138388670107
XKoord26=-103.65505357839
YKoord26=40.0022887766997
XKoord27=-103.621291562179
YKoord27=39.9897544614211
XKoord28=-103.597097908667
YKoord28=39.9763483477889
XKoord29=-103.58214107913
YKoord29=39.963669035358
XKoord30=-103.572330849451
YKoord30=39.9516850235717
XKoord31=-103.565294948203
YKoord31=39.9396276813222
XKoord32=-103.557743013855
YKoord32=39.9272644877781
XKoord33=-103.549916037426
YKoord33=39.9150075522427
XKoord34=-103.543674873954
YKoord34=39.9042996042442
XKoord35=-103.540939734705
YKoord35=39.8993769431917
XKoord36=-103.5390283728
YKoord36=39.8948863647967
XKoord37=-103.538397094504
YKoord37=39.8909886554411
XKoord38=-103.538900764095
YKoord38=39.8889850915685
XKoord39=-103.53956445005
YKoord39=39.8874100767341
XKoord40=-103.540021604024
YKoord40=39.8859944125201
[Symbol 2]
Typ=6
Group=1
Width=20
Height=20
Dir=100
Col=1
Zoom=1
Size=102
Area=2
XKoord=-104.013953514112
YKoord=40.1004735574736
[Overlay]
Symbols=2
[Maplage]
MapName=Bundesrepublik 1:1 Mio
DimmFc=100
ZoomFc=100
CenterLat=39.8859944125201
CenterLong=-103.540021604024
RefOn=0

UI-View Overlay

Here's a sample:

* UI-View Overlay for EOSS-114 prediction
Liftoff!4028.41N/10457.74W/ Alt= 4,981 Ft. .0 mn. Trk=193° Spd= mph
EOSS-114!4028.33N/10457.77W/ Alt= 5,699 Ft. .7 mn. Trk=193° Spd=9 mph
EOSS-114!4028.24N/10457.80W/ Alt= 6,503 Ft. 1.4 mn. Trk=197° Spd=9 mph
EOSS-114!4028.12N/10457.83W/ Alt= 7,326 Ft. 2.2 mn. Trk=190° Spd=11 mph
EOSS-114!4027.89N/10457.79W/ Alt= 8,169 Ft. 2.9 mn. Trk=172° Spd=21 mph
EOSS-114!4027.62N/10457.67W/ Alt= 9,035 Ft. 3.7 mn. Trk=161° Spd=25 mph
EOSS-114!4027.32N/10457.49W/ Alt= 9,925 Ft. 4.5 mn. Trk=156° Spd=28 mph
EOSS-114!4026.66N/10457.08W/ Alt= 11,778 Ft. 6.2 mn. Trk=155° Spd=30 mph
EOSS-114!4025.87N/10456.56W/ Alt= 13,750 Ft. 8.0 mn. Trk=153° Spd=34 mph
EOSS-114!4025.05N/10456.03W/ Alt= 15,863 Ft. 9.9 mn. Trk=154° Spd=33 mph
EOSS-114!4024.21N/10455.52W/ Alt= 18,133 Ft. 12.0 mn. Trk=155° Spd=31 mph
EOSS-114!4023.34N/10454.77W/ Alt= 20,600 Ft. 14.2 mn. Trk=147° Spd=32 mph
EOSS-114!4022.37N/10453.59W/ Alt= 23,314 Ft. 16.7 mn. Trk=137° Spd=37 mph
EOSS-114!4021.29N/10451.57W/ Alt= 26,345 Ft. 19.5 mn. Trk=125° Spd=47 mph
EOSS-114!4020.22N/10448.58W/ Alt= 29,820 Ft. 22.6 mn. Trk=115° Spd=55 mph
EOSS-114!4019.18N/10443.83W/ Alt= 33,914 Ft. 26.3 mn. Trk=106° Spd=70 mph
EOSS-114!4017.67N/10437.01W/ Alt= 38,868 Ft. 30.9 mn. Trk=106° Spd=83 mph
EOSS-114!4015.90N/10427.92W/ Alt= 45,118 Ft. 36.5 mn. Trk=104° Spd=87 mph
EOSS-114!4013.50N/10417.23W/ Alt= 53,507 Ft. 44.2 mn. Trk=106° Spd=77 mph
EOSS-114!4010.20N/10406.77W/ Alt= 67,480 Ft. 56.9 mn. Trk=112° Spd=47 mph
Burst!4006.03N/10400.84W/ Alt= 95,000 Ft. 81.9 mn. Trk=132° Spd=17 mph
EOSS-114!4004.95N/