AIRGrav Airborne Gravity (Level 1)

Level 1 data includes airborne gravity measurements. The line data are hosted in the following folder:

Variable Name Format Units Description
LAT F15.7 degrees Latitude decimal degrees WGS-84
LONG F15.7 degrees Longitude decimal degrees WGS-84
DATE A9 YYYYMMDD Date
DAY A5 DDD Day of year
TIME A11 seconds UTC seconds past midnight (rolls over)
FIDUCIAL F11.2 seconds UTC seconds past midnight (continuous)
PSX F15.2 m Polar stereographic X WGS-84
PSY F15.2 m Polar stereographic Y WGS-84
LAMX F15.2 m Lambert conic conformal X WGS-84
LAMY F15.2 m Lambert conic conformal Y WGS-84
WGSHGT f11.2 m Height WGS-84 (height above GRS80 ellipsoid)
FX F15.2 mGal Gravimeter X acceleration
FY F15.2 mGal Gravimeter Y acceleration
FZ F15.2 mGal Gravimeter Z acceleration
EotGrav F15.2 mGal Eotvos and latitude corrected gravity, unfiltered
FACor F11.2 mGal Free air correction
IntCor F11.2 mGal Intersection levelling correction
FAGrav70s F11.2 mGal Free air gravity, 70s full wavelength filter
FAGrav100s F11.2 mGal Free air gravity, 100s full wavelength filter
FAGrav140s F11.2 mGal Free air gravity, 140s full wavelength filter

Notes:

70s full wavelength filter = 0% pass at 52.5s, 100% pass at 105s
= approx 2.6 km half-wavelength resolution at 75 m/s flying speed

100s full wavelength filter = 0% pass at 75s, 100% pass at 150s
= approx 3.7 km half-wavelength resolution at 75 m/s flying speed

140s full wavelength filter = 0% pass at 105s, 100% pass at 210s
= approx 5.2 km half-wavelength resolution at 75 m/s flying speed

-Positions are for the gravimeter, not the GPS antenna.

-2 Hz data rate

-Line numbering convention used:

The llll.xx where llll is the line number and xx tracks the order in which segments
of the line were flown. For example, line 270.02 is the second segment or reflight flown
of the planned line 270.

In the case of ferry “bonus” lines, the .xx extension is the order in which the ferry lines
were flown in the flight. For example, 2029.03 is the 3rd ferry line in flight 29.

Line numbers are limited to 4 digits plus extension with no letters. The following system
was used to translate LDEO planned lines into a format which fit into 4 digits:

LDEO Scheme SGL Scheme
Ferry “Bonus” Lines Not planned, numbered as they happen.
20000 – 20999
Not planned, numbered as they happen.
20ff, where ff is flight number
Dome A Flight Lines 270 – 760 270-760
Dome A Tie Lines 10090 – 10310 1090-1310
Fuji Tie Lines F01 – F11 Renamed to match Dome A segments
Recovery Trend Lines R01 – R06 4001-4006 (4001-4003 not flown, 4007-4012 added instead)
Vostok Tie Lines V01 – V14 Renamed to match Dome A segments
South Pole Flight Lines S01 – S07 Renamed to match Dome A segments

– Some flights are actually two flights processed together. Flights break down as follows:

001 ::: FLT-1 and 2 from Pole to AGAPS
003 ::: FLT-3
004 ::: FLT-4 and 5 (FLT-5 was a compensation)
006 ::: FLT-6
007 ::: FLT-7
008 ::: FLT-8 and 9
010 ::: FLT-10 and 11
012 ::: FLT-12
013 ::: FLT-13
014 ::: FLT-14
016 ::: FLT-16
017 ::: FLT-17 and 18
019 ::: FLT-19 and 20
021 ::: FLT-21 and 22
023 ::: FLT-23
024 ::: FLT-24 and 25
026 ::: FLT-26 and 27
029 ::: FLT-28 and 29 (FLT-28 was a compensation, gravity not processed for that portion of flight)
030 ::: FLT-30 and 31
032 ::: FLT-32 and 33
034 ::: FLT-34
035 ::: FLT-35 and 36
037 ::: FLT-37 and 38
039 ::: FLT-39
040 ::: FLT-40 and 41
042 ::: FLT-42 and 43
044 ::: FLT-44
045 ::: FLT-45
046 ::: FLT-46
047 ::: FLT-47
048 ::: FLT-48 and 49
050 ::: FLT-50 and 51
052 ::: FLT-52