Larsen & Brusgaard ALTITRACK Manual page 39

TAS is a term used in aviation: It is the speed of an object relative to the sur-
rounding air, regardless of the altitude.
SAS is a new concept developed by LARSEN & BRUSGAARD: SAS is the speed of a
skydiver calculated from measurements of air pressure and temperature and con-
verted to a fixed air pressure (875.3 mb) and a fixed temperature (+7.080C) which
corresponds to 4,000 feet ASL.
TAS
A skydiver's True Airspeed (TAS) relative to the ground changes as a function of the
altitude (air pressure) and temperature which makes it difficult to compare fall-rates.
Example: A skydiver (in a fixed freefall position) who has a terminal fallrate of
62 meters/sec at 10,000 feet will have a terminal fallrate of 50 meters/sec at 3,000
feet.
It will be seen that the difference in altitude (air pressure) makes it difficult to
compare the fall-rates when measured using TAS.
See paragraph 18 for more information about TAS and SAS.
Note: Jump data are continuously stored in both TAS and SAS. Stored information may
be displayed in either unit of measurement by selecting the respective mode.
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