The Antarctic Iceberg Tracking Database
1978 & 1992-2016 (Brigham Young University)
Traci Fletcher, Jeff Budge, Elizabeth Robinson, Emily Prigmore, Jordan Hill,
Nathan Madsen, Steven Reeves, Keith Stuart, Ben Lambert, Jarom Ballantyne, and David G. Long
Last database update: April 21,  2016 (for current positions click here)
(Iceberg Tracks from 1999-2010)
Using six different satellite scatterometer instruments, we have produced
an iceberg tracking database. The BYU database includes icebergs
identified in enhanced resolution scatterometer backscatter images during
July-Sept. 1978 (from Seasat), July 1996-June 1997 (from NSCAT),
1992-2001 (from ERS-1/2), June 1999-November 2009 (from QuikSCAT), 2008-present (from ASCAT),
2012-2014 (from OSCAT).
Images were obtained from the Scatterometer
Climate Record Pathfinder (SCP) project.
Data sets from seven different spaceborne scatterometer instruments
are used to track icebergs. For each data set, resolution
enhancement is performed by BYU's Scatterometer Image reconstruction
(SIR) and/or SIR Filtering (SIRF) algorithms. The scatterometer
instruments used in this study are the Seasat-A Satellite
Scatterometer (SASS), the European Space Agency's Remote Sensing
Satellite 1(2) (ERS-1/-2), the NASA Scatterometer (NSCAT), the
QuikSCAT/SeaWinds scatterometer (QSCAT), the MetOp-A and MetOp-B
Advanced Scatterometer (ASCAT) sensors, and the Indian Space Research
Organization's Oceansat-2 scatterometer. The Seasat-A
scatterometer (SASS) was a dual-polarization Ku-band (14.6 GHz)
scatterometer that operated from July to Sept. 1978. Using the SIRF
algorithm, Antarctic images are generated every 12 & 48 days (a
longer time is required for SASS compared to other instruments due to
the sampling characteristics of the nominally 50 km backscatter
measurements). The ERS-1/2 spacecraft carried a C-band (5.3 GHz)
active microwave instrument (AMI). The scatterometer mode
provides nominally 50 km resolution data. Using SIR, Antarctic
images are produced every 6 days. The ERS-1/2 scatterometers
operated from Jan. 1992 to Jan. 2001. The NSCAT scatterometer is
a Ku-band Doppler radar similar to SASS, but with dual-side
measurement capability and a dense 25 km resolution sampling.
Using SIRF, Antarctic images were produced every 3 days. The
NSCAT mission lasted from Sept. 1996 to June 1997. QuikSCAT was
launched as a ``quick recovery'' mission to help fill the gap created
by loss of NSCAT due a satellite failure. This scatterometer
allows daily images of Antarctica to be created. QuikSCAT
operated from July 1999 to November 2009. ASCAT was launched in
October of 2006 and is currently operational. ASCAT operates at C-Band
(5.255 GHz) at vertical polarization only. The SIRF algorithm
applied to ASCAT (Standard BYU ASCAT Land/Ice
Products) generates images from 1 and 2 days of data over
Antarctica. Iceberg tracks for ASCAT have only been done back to the
beginning of the ASCAT data. This provides an overlap of two data sets
(QuikSCAT and ASCAT) for a few years (October 2006 to November
2009).  The Oceansat-2 scatterometer (OSCAT-1) dataset begins August 2011
and continues through the end of March 2014. Its antenna geometry and
frequency are similar to that of QuikSCAT. A follow-on OSCAT mission (OSCAT-2 on ScatSat) began in Nov. 2016, and is currently be used for iceberg tracking.
The initial position for each iceberg is located based on either
(1) a position reported by the National Ice Center (NIC)'s web page
(https://www.natice.noaa.gov//pub/icebergs/Iceberg_Tabular.pdf)
or (2) by the sighting of a moving iceberg in a time series of
scatterometer images. From an initial start point, the iceberg
is tracked in the scatterometer image time series. Gaps in the
position track result from missing scatterometer data and from the
occasional loss of contrast between the iceberg and surrounding area
during summer months. For each image a lat/lon position is
reported for each iceberg, with mostly daily position updates. Sizes
are not reported.
Iceberg positions are reported in a separate ASCII text file for each
iceberg. The file name is the same as that of the iceberg. For example
the file "b27.ascat" contains the position track information for B27 from ASCAT.
A few lines from the b27.ascat file are shown below:
lat: -72.8568 lon: -119.7036 day: 326 2009 file: msfa-a-Ant09-326-326.sir backscat: -7.657
lat: -72.8927 lon: -119.8380 day: 327 2009 file: msfa-a-Ant09-327-327.ave backscat: -9.348
lat: -72.9339 lon: -119.6691 day: 328 2009 file: msfa-a-Ant09-328-328.ave backscat: -8.874
Note that latitude and longitude are specified in decimal degrees
with positive North and East, respectively. The day is specified
as: "day of the year" year. The file lists the scatterometer image
file from the SCP image set used to track the selected position. 
The backscat data is the backscatter value returned by the
scatterometer.
The iceberg database can be obtained via the links shown
below. If desired, data can be imported into Microsoft Excel or
other spreadsheet programs as "space delimited data". Note that ASCAT
and OSCAT data files are in a more abbreviated format than those of
previous data files.
ASCAT-A/B and OSCAT-2 are now the primary sensors. While the real-time positions are updated weekly or more often, the full database files referred to on this page are only updated a few times per year.
If you become aware of a large (>5 km) Antarctic iceberg not contained in the database during the time period of our sensors, please inform us of its position and the time of observation. We can then use historical data to determine its origin and fate and add it to the tracking database.
As of 12 July 2017, the top Antarctic icebergs ranked by size are:
Iceberg | Area (sq km) |
B15 | 11000 |
A20 | 7284 |
A24 | 6863 |
C19 | 6368 |
A23 | 5883 |
A68 | 5800 |
B10 | 5689 |
A38 | 5603 |
A22 | 5212 |
B09 | 5096 |
DATABASE FILES
ASCAT portion of the database in a gzipped tar file from the SCP web site: icebergDatabase_ascat.tar.gz
QSCAT portion of the database in a gzipped tar file from the SCP web site: icebergDatabase_qscat.tar.gz
OSCAT portion of the database in a gzipped tar file from the SCP web site: icebergDatabase_oscat.tar.gz
All other portions (SASS, ERS-1/2, NSCAT) in a gzipped tar file from the SCP web site: icebergDatabase_other.tar.gz
Individual iceberg tracking files are available for each sensor through
the web links below.
INSTRUMENT
|
TIME PERIOD
|
SASS
|
July 1978 - Sept. 1978
|
ERS-1/2
|
Jan. 1992 - Jan. 2001
|
NSCAT
|
Sept. 1996 - June 1997
|
SeaWinds
|
April 2003 - October 2003
|
QSCAT
|
July 1999 - November 2009
|
OSCAT
|
November 2010 - February 2014
|
ASCAT
|
November 2009 - Present
|
Related papers:
K.M. Stuart and D.G. Long, "Tracking large tabular icebergs using the SeaWinds Ku-band microwave scatterometer", Deep-Sea Research Part II,
doi:10.1016/j.dsr2.2010.11.004, Vol. 58, pp. 1285-1300, 2011.
(1.6 MB PDF)
D.G. Long, Jarom Ballantyne, and C. Bertoia, "Is the Number of Icebergs Really Increasing?" EOS, Transactions of the American Geophysical Union, Vol. 83, No. 42, pp 469 & 474, 15 Oct. 2002.
(620 kB PDF)
K.M. Stuart and D.G. Long, "Iceberg Size and Orientation Estimation using SeaWinds", Cold Regions Science and Technology, doi:10.1016/j.coldregions.2011.07.006, 2011. (1.7MB PDF)
An older report further describing this multidecadal database of Antarctic
icebergs observed with scatterometer data is available in pdf format from
the SCP web site at IcebergReport.
Animations of the daily movement of selected individual icebergs can be found here. Note that many icebergs do not move for long periods of time.
Support from both NASA and NSF is acknowledged.
Last Revised: July 11, 2017
For further information contact:
Dr. David G. Long
long@ee.byu.edu
Professor, Electrical and Computer Eng. Dept. https://www.ee.byu.edu/
Brigham Young University
https://www.byu.edu/
459 Clyde Building
voice: 801-422-4383
Provo, Utah 84602
fax: 801-422-0201
Microwave Earth Remote Sensing (MERS) Lab: https://www.mers.byu.edu/
Scatterometer Climate Record Pathfinder: https://www.scp.byu.edu/
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