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http://www.navcen.uscg.gov/?pageName=NAISmain |
Source Citation URL |
Source Citation URL |
information |
| 4 |
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https://coast.noaa.gov |
NOAA Office for Coastal Management Website |
NOAA Office for Coastal Management Home Page |
information |
| 1 |
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https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords |
GCMD Keyword Forum Page |
Global Change Master Directory (GCMD). 2024. GCMD Keywords, Version 19. Greenbelt,
MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard
Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA).
URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords |
information |
| 1 |
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https://marinecadastre.gov/data/ |
https://marinecadastre.gov/data/ |
Marine Cadastre Data Registry |
download |
| 1 |
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https://marinecadastre.gov/downloads/data/ais/ais2009/CommercialVesselDensityOctober2009_2010UTM10S.zip |
https://marinecadastre.gov/downloads/data/ais/ais2009/CommercialVesselDensityOctober2009_2010UTM10S.zip |
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download |
| 1 |
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https://www.fisheries.noaa.gov/inport/item/48864 |
Full Metadata Record |
View the complete metadata record on InPort for more information about this dataset. |
information |
| 1 |
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https://www.fisheries.noaa.gov/inportserve/waf/noaa/nos/ocm/dmp/pdf/48864.pdf |
NOAA Data Management Plan (DMP) |
NOAA Data Management Plan for this record on InPort. |
information |
| 1 |
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2012-07-01T00:00:00 |
Source data derived from the raw AIS data processing is as follows:
The USCG maintains a network of AIS receivers that collects AIS messages from passing
ships. These data are transmitted to USCG data center that compiles the data and provides
data feeds to other government agencies. In accordance with the USCG COMDTINST 5230.80,
the USCG provided OCS with a "Level A" data feed. Level A is unfiltered real-time
data that is less than 96 hours from initial time of transmission. OCS has subscribed
to this data since 2008. To limit data storage requirements the data feed was filtered
by the USCG to only send one position message per ship per minute and all duplicate
messages (i.e. ship broadcasts received by more than one NAIS station) were removed.
This real time feed was archived at OCS. A specialized software NOAADATA.py (K. Schwehr.
The noaadata-py Software Tool-set, v0.42, 2009. http://vislab-ccom.-unh.edu/schwehr/software/noaadata)
is used to create daily files and and load the data into an Oracle Spatial database.
Despite receiving this filtered feed, a great deal of conditioning needs to take place
to prepare this data to be analyzed. The AIS system was not intended or designed for
subsequent analysis; however Calder and Schwehr ably proved, given the proper conditioning,
AIS data can be used for traffic analysis. ( B. R. Calder., K. Schwehr. Traffic
Analysis for the Calibration of Risk Assessment Methods. Proceedings: US Hydrographic
Conference 2009, Norfolk, VA, 11-14 May 2009, http://www.thsoa.org/us09papers.htm)
Based on their research, we filtered out AIS messages with non-unique user IDs and
vessels with erroneous dimensions. We also separated messages by speed, separating
those reporting a speed of less than 0.4 knots into a separate anchored table.
The accuracy and abundance of the AIS data support high resolution analysis specifically
within port areas. This study however was interested in traffic patterns on a macro
scale so patterns could be analyzed across the coastal waters of the Continental United
States. To limit the processing time and the overall file size for each region a
grid cell size of 1 kilometer was chosen.
For this dataset a transits is counted for every unique vessel intersecting a grid
cell each day. Multiple trips into a grid cell on a given day by the same vessel are
only counted as one transit. Instead of calculating transits based on the coordinates
within the AIS message transit lines were created by connecting all the vessels reports
each day. Traffic counts were then calculated by summing the number of lines within
each cell. Although this dataset only contains the total traffic count "TRNSTS_TTL"
the original dataset has transits by AIS vessel type and many other attributes as
well. Processed from May - July 2012.
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| 1 |
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2012-10-15T00:00:00 |
Further data development processing followed to obtain this feature class:
Acquire original source data and maintain a copy on the development tier, create geodatabase
import the original shapefiles. Delete all feature will zero values and validate the
feature classes' geometry (Data Management > Features > Repair Geometry). Acquire,
create and update metadata from providers (as needed). Compressed data set into a
zip file for ease of download.
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