you got home? Either you or one of
your crew members will have saved
a TNC log of the flight. It is a copy
of all the APRS traffic during the
mission. This is a text file, so it’s
readable with a text editor, like
Wordpad (it may be too large for
Open the TNC log with the text
editor of your choice. The first thing
you’ll notice is that there is a great
deal of traffic from chase crews and
local hams. In fact, most of the text
you see has nothing to do with the
posits from your NS craft. Make
yourself a cup of tea because you’re
going to be editing the TNC log for
The first step is to delete lines of
text that did not originate from your
Tiny Trak 3. Delete every sentence
that does not begin with your
callsign. Save your file frequently.
If a digi-peater was within range,
you’ll see some posits that were
repeated before getting to your
APRS station. In those cases, you’ll
see something that looks like the
data in Example 2.
NUTS & VOLTS
Notice that, except for the
destination field, the second
posit is identical to the first
one. Realizing this, our next
step is to delete all of the
repeated posits. I prefer to
do this manually to ensure
accuracy. Before making
deletions, look carefully at
the posits. There may be
times when you only see the
repeated posit, not the original one. Be sure that you
don’t delete the repeated
posit if your TNC log does
not contain the original
posit. Save your work again.
Next, get rid of the callsign
and routing information. In
Example 2, this means:
Here’s where the Find/Replace
feature comes in handy. In
WordPad, select “Edit,” then
“Replace.” In the “Find What” field,
type the callsign and route text.
Leave the “Replace With” field
blank. Now click “Replace All.”
Sit back and watch your PC
make editing changes at warp
factor six. You may notice that
there were some damaged or
repeated posits that didn’t contain
the information in the “Find What”
field. You’ll have to clean these up
manually, unless you have lots of
repeated posits. Save your work
Now you are left with sentences
that look like that in Example 3.
Use the “Replace All” option to
replace the following characters
with a comma:
Be sure to do the last two in
the order indicated and to save your
work after every replacement.
Now you have posits that look
like that in Example 4.
The last step is to add commas
between the hours, minutes, seconds,
and minutes of latitude and longitude.
Again, I have found that it is more
accurate to do this manually.
Don’t forget to save the changes
Your final result will be a text
file that looks like Example 5.
Congratulations — the hard
work is over and the fun stuff
You’re now ready to import
the text file into a spreadsheet.
I’ll explain how I do this in
Excel. Even if you use another
spreadsheet, you should find the
procedure to be similar.
When you open the text file in
Excel, it will ask how the text file is
formatted. Tell the Text Import
Wizard that the file is delimited
and, in the second screen,
specify that only commas
delimit the file. On the
third screen, click the
Finish button. Look over
the spreadsheet and verify
that there were no errors in
formatting the TNC log.
If you find an error,
back out of the file without
saving it, make the
necessary changes to the
modified text file, and then
repeat the process of
importing the file back into
Excel. If you’re happy with
the results, save the file.
Now let’s produce some
Inside the near space module. The sturdy sides
insulate and protect the data logger so that
your information stays secure.