IGC File Name Decoding Made Easy

I had a pile of log files of my flights this summer. I typically
transfer files from my flight recorder to my PC via my IPAQ's removable
compact flash (CF) card.

Unfortunately, the IPAQ had the wrong date (year, time, everything) so
it was a little difficult figuring out which log file was which based
on the date stamp of the file.

However, there is a way out of this dilemma. The IGC file is named by
the flight recorder in such a way that it "encodes" the date when the
flight was made along with other information.

Below is your personal decoder ring for IGC file names.

Enjoy, John
email: johnatderosaweb.com

================================================== =====

YMDCXXXF.IGC
||||\ /|
|||| | |
|||| | +--- F=Flight # of day 1-9 then A-Z (35 flights max)
|||| +----- XXX=Serial number of logger (3 alpha-numberic digits)
|||+------- C=Manufacturer of logger (see note below)
||+-------- D=Day of month (see note below)
|+--------- M=Month of year (see note below)
+---------- Y=Last digit of year

Example
=======
5AGC3WK1.IGC

October, 16, 2005
Cambridge recorder serial number 3WK
Flight #1

Numbering Breakdown
===================
Month of year
-------------
1 = January
2 = February
3 = March
4 = April
5 = May
6 = June
7 = July
8 = August
9 = September
A = October
B = November
C = December

Day of Month
------------
1 = 1
2 = 2
3 = 3
4 = 4
5 = 5
6 = 6
7 = 7
8 = 8
9 = 9
A = 10
B = 11
C = 12
D = 13
E = 14
F = 15
G = 16
H = 17
I = 18
J = 19
K = 20
L = 21
M = 22
N = 23
O = 24
P = 25
Q = 26
R = 27
S = 28
T = 29
U = 30
V = 31

Manufacturer of Data logger
---------------------------
A = Garrecht
C = Cambridge
E = EW Avionics
F = Filser
L = LX Navigation
S = Streamline data instruments
W = Westerboer
X = All other manufacturers

Full technical specs for the IGC files can be found at:
http://www.fai.org/gliding/gnss/tech_spec_gnss.pdf

ContestID67 wrote:
I had a pile of log files of my flights this summer. I typically
transfer files from my flight recorder to my PC via my IPAQ's removable
compact flash (CF) card.

Unfortunately, the IPAQ had the wrong date (year, time, everything) so
it was a little difficult figuring out which log file was which based
on the date stamp of the file.

However, there is a way out of this dilemma. The IGC file is named by
the flight recorder in such a way that it "encodes" the date when the
flight was made along with other information.

Below is your personal decoder ring for IGC file names.

Enjoy, John
email: johnatderosaweb.com

================================================== =====

YMDCXXXF.IGC
||||\ /|
|||| | |
|||| | +--- F=Flight # of day 1-9 then A-Z (35 flights max)
|||| +----- XXX=Serial number of logger (3 alpha-numberic digits)
|||+------- C=Manufacturer of logger (see note below)
||+-------- D=Day of month (see note below)
|+--------- M=Month of year (see note below)
+---------- Y=Last digit of year

Example
=======
5AGC3WK1.IGC

October, 16, 2005
Cambridge recorder serial number 3WK
Flight #1

Or, could be 1995. Or 2015. With all the stink about Y2K,
it's a little surprising they came up with a scheme that has
a 10 year rollover problem.

-Dave

"David Kinsell" wrote in message
...

Or, could be 1995. Or 2015. With all the stink about Y2K,
it's a little surprising they came up with a scheme that has
a 10 year rollover problem.

NOW it would be very easy decode the year by base 36 number to push the
problem until 2035...

Only they decided on format in the last millenium.

hannu

hannu wrote:
"David Kinsell" wrote in message
...


Or, could be 1995. Or 2015. With all the stink about Y2K,
it's a little surprising they came up with a scheme that has
a 10 year rollover problem.


NOW it would be very easy decode the year by base 36 number to push the
problem until 2035...

That's the weird thing. They used digits and characters for the date,
they used digits and characters for the month, and just used digits
for the year.



Only they decided on format in the last millenium.


Yep. I guess some people just can't think ahead :-)


hannu

X-no-archive: yes
In article , David Kinsell
writes
hannu wrote:
"David Kinsell" wrote in message
...


Or, could be 1995. Or 2015. With all the stink about Y2K,
it's a little surprising they came up with a scheme that has
a 10 year rollover problem.


NOW it would be very easy decode the year by base 36 number to push the
problem until 2035...

That's the weird thing. They used digits and characters for the date,
they used digits and characters for the month, and just used digits
for the year.



Only they decided on format in the last millenium.


Yep. I guess some people just can't think ahead :-)

As I recall, IGC adopted a file naming system which was used on the
early Cambridge Recorders, which pre-date the specification. But any
flight that is 10 years old or more is history.

The 8-digit filename came about when DOS and Windows where limited to
8-digits. The specification now allows for Long Filenames (see
Specification Appendix 1 Paragraph 2.5.2) but no-one seems to use them.

In the unlikely event of a clash of filenames being problematical,
rename them to the long format. Problem Solved.

Tim Newport-Peace

"Indecision is the Key to Flexibility."

Bet you the cost of a tow that they come out with a new igc "standard"
before 2015...

Hey, wait...I'm not going to bet a tow, that could be $100 or
more...based on the other postings.

Maybe IGC will require USB connections...as they get phased out for ???

FWIW, I'm still using a VolksLogger with DOS, having sought out an
"old" laptop that has a com port, and thrashed the computer into a dual
boot system (using System Commander software) so that I can use the
Garrecht "secure" DOS download software ("vali.exe"), then reboot to
WinXP and get useful information from the trace using SeeYou.

Those that know me know I do EVERYTHING the hard way (e.g., fly a
1-26).

Thanks for the decoder ring; it sure is nice to understand the
gibberish naming of the file, I think.

-Pete

X-no-archive: yes
In article .com, 309
writes
Bet you the cost of a tow that they come out with a new igc "standard"
before 2015...

Two Years ago actually.

Hey, wait...I'm not going to bet a tow, that could be $100 or
more...based on the other postings.

Maybe IGC will require USB connections...as they get phased out for ???

FWIW, I'm still using a VolksLogger with DOS, having sought out an
"old" laptop that has a com port, and thrashed the computer into a dual
boot system (using System Commander software) so that I can use the
Garrecht "secure" DOS download software ("vali.exe"), then reboot to
WinXP and get useful information from the trace using SeeYou.

Those that know me know I do EVERYTHING the hard way (e.g., fly a
1-26).

You must do. There is a Free Windows shell program and Volkslogger DLL
available from http://www.fai.org/gliding/gnss/freeware.asp

Tim Newport-Peace

"Indecision is the Key to Flexibility."

The American marines did it before the IGC - they had a system which hit
the decade rollover in 1980

Rgds,

Derrick Steed

To IGC's defence, some of that issue could be traced to DOS, with it's
file name limitation (8 characters maximum).

Admittedly, hex/alpha coding year would extend the rollover period, but
make it yet more difficult for us to track our flight files...

And there was a GPS clock rollover back in the '90's, wasn't there? Or
did I sleep through the alarm clock?

-Pete

On Tue, 06 Sep 2005 13:41:53 +0100, Tim Newport-Peace wrote:

As I recall, IGC adopted a file naming system which was used on the
early Cambridge Recorders, which pre-date the specification. But any
flight that is 10 years old or more is history.

The 8-digit filename came about when DOS and Windows where limited to
8-digits. The specification now allows for Long Filenames (see
Specification Appendix 1 Paragraph 2.5.2) but no-one seems to use them.

There's one unexplained item in the GNSS file specification: some loggers,
e.g. the EW model D, have a serial number of the form Dnnnn which does not
convert into the three alphanumeric characters in any obvious way. There's
not a hint in the file specification as to how this feat might be
performed.

The serial number is specified as three alphanumeric characters in both
short and long form file names.

--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |