IGC and IGC+ data logs

The IGC files generated at the end of the flight by the Vector Vario comply with the FAI CIVL standard and can be validated online on the servers of the FAI CIVL and XContest. The Vector Vario even offers IGC+ by default, an enriched version of the standard flight data recording, which enables a more detailed analysis of flight parameters and atmospheric conditions.

The classic IGC data log

In a standard IGC file, B records provide, every second:
  • UTC time
  • Geographical coordinates
  • Barometric altitude
  • GPS altitude
For example, here are three lines from a standard IGC recording, between 12:16:21 and 12:16:23 UTC: 
B1216214812743N00411898EA0222902249
B1216224812744N00411897EA0223002249
B1216234812746N00411897EA0223002250

The IGC+ data log

An IGC+ recording adds an additional line of data each second, including:

  • air temperature
  • relative humidity of the air
  • the raw air speed (IAS)
  • wind origin direction and speed
  • netto (vertical wind component)
  • attitude (heading, pitch, roll)
  • load factor (G's)

This additional line starts with the prefix LXVV and complements the standard B record every second.
Here is the same 3-second recording example with the extended IGC+ data:

B1216214812743N00411898EA0222902249
LXVVT+101H352I101W012023N+012D248+006-002G010
B1216224812744N00411897EA0223002249
LXVVT+101H352I102W013023N+013D247+008-004G011
B1216234812746N00411897EA0223002250
LXVVT+101H352I101W012023N+013D245+010-007G012

IGC+ line structure

An IGC+ recording encodes its data in blocks, where the first character of each block indicates the data type and its length:

  • LXVV is the prefix that marks the beginning of every IGC+ line. These lines are included in the IGC file’s integrity check system (G-record) and must not be altered.
  • The presence of these additional data lines does not affect the validation of your flight log, which is based solely on the B records.
  • Each data field starts with a capital letter (A–Z) that defines both the type of data and its length. The order of the fields is not important.
Prefix Description Format Divider Value range
T Air temperature ±XXX 10 -99.9 à +99.9 °C
H Relative humidity XXX 10 0.0 à 99.9 %
I Vitesse air (IAS) XXX 10 0.0 à 99.9 m/s
W Wind origin direction & speed DDDSSS Origin (DDD): 1
Speed (SSS): 10		 Origin: 0 to 359°
Speed: 0.0 à 99.9 m/s
N Netto ±XXX 10 -99,9 à +99,9 m/s
D Attitude: XXX±YYY±ZZZ Heading (XXX) : 1
Pitch (YYY) : 1
Roll (ZZZ) : 1		 Heading: 0 to 359°
Pitch: -90 à +90°
    (positive upward)
Roll: -180 à +180°
    (positive to the right)
G G-force XXX 10 0.0 à 99.9 G

For example, here is the decoded content of the following IGC+ line:

LXVVT+101H352I101W012023N+012D248+006-002G010
  • T+101  → Air temperature of +10.1  °C
  • H352  → Relative humidity of 35.2  %
  • I101  → Vitesse air (Indicated Air Speed) de 10,1 m/s
  • W012023 → Wind of 2.3 m/s coming from an azimuth of 12° (relative to true north)
  • N+012  → Netto (vertical wind component) of +1.2 m/s
  • D248+006-002 → Heading 248° (relative to true north), 6° pitch upward, 2° roll to the left
  • G010  → Load factor of 1.0 G