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Description of ATM QFIT Output Data

Acquire IceBridge ATM icessn data:
https://github.com/tsutterley/nsidc-earthdata

IceBridge Flight Summaries:
https://nsidc.org/data/icebridge/campaign_data_summary.html

Pre-IceBridge ATM L1B Elevation and Return Strength

https://nsidc.org/data/BLATM1B

IceBridge ATM L1B Elevation and Return Strength

https://nsidc.org/data/ILATM1B/1
https://nsidc.org/data/ILNSA1B/1

10-word format (used prior to 2006)

Variables	Description
time	Relative Time (seconds from start of data file)
latitude	Laser Spot Latitude (degrees)
longitude	Laser Spot Longitude (degrees)
elevation	Elevation above WGS84 ellipsoid (meters)
xmt_sigstr	Start Pulse Signal Strength (relative)
rcv_sigstr	Reflected Laser Signal Strength (relative)
azimuth	Scan Azimuth (degrees)
pitch	Pitch (degrees)
roll	Roll (degrees)
time_hhmmss	GPS Time packed (153320.1000 = 15h 33m 20.1s)

12-word format (in use since 2006)

Variables	Description
time	Relative Time (seconds from start of data file)
latitude	Laser Spot Latitude (degrees)
longitude	Laser Spot Longitude (degrees)
elevation	Elevation above WGS84 ellipsoid (meters)
xmt_sigstr	Start Pulse Signal Strength (relative)
rcv_sigstr	Reflected Laser Signal Strength (relative)
azimuth	Scan Azimuth (degrees)
pitch	Pitch (degrees)
roll	Roll (degrees)
gps_pdop	GPS PDOP (dilution of precision)
pulse_width	Laser received pulse width (digitizer samples)
time_hhmmss	GPS Time packed (153320.1000 = 15h 33m 20.1s)

14-word format (used in some surveys between 1997 and 2004)

Variables	Description
time	Relative Time (seconds from start of data file)
latitude	Laser Spot Latitude (degrees)
longitude	Laser Spot Longitude (degrees)
elevation	Elevation above WGS84 ellipsoid (meters)
xmt_sigstr	Start Pulse Signal Strength (relative)
rcv_sigstr	Reflected Laser Signal Strength (relative)
azimuth	Scan Azimuth (degrees)
pitch	Pitch (degrees)
roll	Roll (degrees)
passive_sig	Passive Signal (relative)
pass_foot_lat	Passive Footprint Latitude (degrees)
pass_foot_long	Passive Footprint Longitude (degrees)
pass_foot_synth_elev	Passive Footprint Synthesized Elevation (meters)
time_hhmmss	GPS Time packed (example

nsidc_convert_ILATM1b.py

• Alternative program to convert ATM Level-1B data from NSIDC directly into HDF5 files.
• Will not download the QFIT files locally.

python nsidc_convert_ILATM1b.py --user=<username> --mode=0775  

-Y X, --year=X: years to sync separated by commas
-S X, --subdirectory=X: subdirectories to sync separated by commas
-U X, --user=X: username for NASA Earthdata Login
--directory: local working directory
-M X, --mode=X: Local permissions mode of the directories and files synced
-V, --verbose: Verbose output of files synced
-C, --clobber: Overwrite existing data in transfer