BYU/NIC iceberg database¶
The consolidatedBYU/NIC iceberg database is described in the paper J.S. Budge and D.G. Long, "A Comprehensive Database for Antarctic Iceberg Tracking Using Scatterometer Data," IEEE Journal of Selected Topics in Applied Earth Observations, Vol. 11, No. 2, doi:10.1109/JSTARS.2017.2784186, 2017.
Original readme¶
---------------------------------------------------------- BYU MERS Consolidated Antarctic Iceberg Database --Jeff Budge, BYU Nov 2016 -- w/revisions by D.G. Long, BYU Nov 2017, Jun 2019, Aug 2019---------------------------------------------------------This readme is intended to explain the contents the database.Details about how the database is created are contained inJ.S. Budge and D.G. Long, "A Comprehensive Database for AntarcticIceberg Tracking Using Scatterometer Data," IEEE Journal ofSelected Topics in Applied Earth Observations, accepted andto appear, 2017. Related papers: K.M. Stuart and D.G. Long,"Tracking large tabular icebergs using the SeaWinds Ku-bandmicrowave scatterometer", Deep-Sea Research Part II, doi:10.1016/j.dsr2.2010.11.004, Vol. 58, pp. 1285-1300, 2011.D.G. Long, Jarom Ballantyne, and C. Bertoia, "Is the Number ofIcebergs Really Increasing?" EOS, Transactions of the AmericanGeophysical Union, Vol. 83, No. 42, pp. 469 & 474, 15 Oct 2002.FILESEach file in the consolidated database contains information on onenamed iceberg. The name of the iceberg is also the name of the filewith a .csv extension. The headers of each file show the date,sensors, and sizes associated with that iceberg. A few notes:-Each file shows only the sensors that have data available for that iceberg. This means that the number of columns in each file is variable.-Each sensor has at least two columns associated with it, namely 'sensor_1' and 'sensor_2' where "sensor" is replaced with the actual sensor name. 'sensor_1' is the latitude and 'sensor_2' is the longitudinal measurement from each sensor on the given date. The values of 0,0 are used for no data.-Most sensors have a third column, 'sensor_3' that is a binary flag that indicates if the measurement is an observation (1) or has been interpolated (0) for that day or not. Where possible, daily position reports are provided by interpolating sensor observations. Interpolation is only used when (1) the time gap is less than 14 days and (2) the spatial displacement between observation is less than 3 deg latitude or longitude. Interpolated positions that end up over land are not included.-Dates are shown in JD format, with the four digit year first followed by the three digit day of the year.-'size_1' and 'size_2' show the length of the major and minor axes of the iceberg on the date, as given by the NIC, in nautical miles. To convert to km, multiply the value by 1.852.-Standard NIC icebergs names begin with a, b, c, or d which gives the origin quadrant. Additional icebergs were identified in scatterometer data. These unnamed icebergs are stored in files that begin with sa (SASS 1978), e (ERS1/2 1992-2001), or uk (1999-present).KNOWN ISSUESNIC positions are derived from NIC reports. Some inconsistencies anderrors exist in these reports. NIC observation dates are irregularand infrequent, especially in the early days. There are occasionswhen the NIC reports for a single iceberg seem to have been actuallyfrom two different icebergs. While some corrections have been made,NIC reports are generally used as is. While icebergs due not growin size, some NIC reports show size increase. This may be due to(1) quantization of the reported dimensions by NIC and/or (2) variationsin the subjectively choosen axes used to infer dimensions.Scatterometer sensor position estimates have gaps due to loss of dataand backscatter constrast, especially during summer months, buttypically are available on a daily basis. The iceberg center inscatterometer data reports is subjectively determined based onscatterometer backscatter images may not coincide with the centeridentified in NIC reports.In [1]:
importpandasaspdimportmovingpandasasmpdimportzipfileimportwarningswarnings.filterwarnings("ignore")
In [2]:
zf=zipfile.ZipFile("../data/icebergs_v5.zip")df=pd.read_csv(zf.open("consol/uk319.csv"))df["t"]=pd.to_datetime(df.date,format="%Y%j")df
Out[2]:
| ascat_1 | ascat_2 | ascat_3 | date | oscat_1 | oscat_2 | oscat_3 | t | |
|---|---|---|---|---|---|---|---|---|
| 0 | -66.5449 | -35.8440 | 1 | 2011242 | -66.5449 | -35.8440 | 1 | 2011-08-30 |
| 1 | -66.4574 | -35.7165 | 1 | 2011243 | -66.4574 | -35.7165 | 1 | 2011-08-31 |
| 2 | -66.4596 | -35.6281 | 0 | 2011244 | -66.4596 | -35.6281 | 0 | 2011-09-01 |
| 3 | -66.4654 | -35.5435 | 0 | 2011245 | -66.4654 | -35.5435 | 0 | 2011-09-02 |
| 4 | -66.4732 | -35.4662 | 0 | 2011246 | -66.4732 | -35.4662 | 0 | 2011-09-03 |
| ... | ... | ... | ... | ... | ... | ... | ... | ... |
| 390 | -56.6569 | -13.0141 | 1 | 2012267 | -56.6569 | -13.0141 | 1 | 2012-09-23 |
| 391 | -56.6628 | -13.1049 | 1 | 2012268 | -56.6628 | -13.1049 | 1 | 2012-09-24 |
| 392 | -56.5945 | -13.1816 | 1 | 2012269 | -56.5945 | -13.1816 | 1 | 2012-09-25 |
| 393 | -56.5236 | -13.3450 | 1 | 2012270 | -56.5236 | -13.3450 | 1 | 2012-09-26 |
| 394 | -56.5863 | -13.2304 | 1 | 2012271 | -56.5863 | -13.2304 | 1 | 2012-09-27 |
395 rows × 8 columns
In [3]:
traj=mpd.Trajectory(df,traj_id=1,t="t",x="ascat_2",y="ascat_1")traj.hvplot(title="Iceberg trajectory",c="ascat_3",line_width=5,cmap=["yellow","blue"],colorbar=True,)
Out[3]:
In [4]:
traj.explore(color="#ff00ff",tiles="CartoDB dark_matter",style_kwds={"weight":4})
Out[4]:
Make this Notebook Trusted to load map: File -> Trust Notebook
Non-default projections¶
In [5]:
importgeoviewsasgvimportgeoviews.featureasgffromcartopyimportcrs
In [6]:
(gf.coastline*traj.hvplot(title="Iceberg trajectory in SouthPolarStereo",tiles=None)).opts(projection=crs.SouthPolarStereo())
Out[6]: