Commercial Vessel Density October 2009-2010 AIS UTM19
Dataset Identification:
Resource Abstract:
These data were generated to provide insight into marine traffic patterns on a macro scale so they could be analyzed across
the coastal waters of the Continental United States, this data set is for the UTM Zone 19N. For this dataset a transit is
counted for every unique vessel intersecting a 1 kilometer square grid cell each day. This data represents the total number
of vessel transits from October 2009 - October 2010. Some grid cells were unable to be processed, but this does not interfere
with the integrity of this dataset. Please note multiple connection errors occurred during the time frame of this study. In
most cases data gaps were filled by making subsequent request to the coastguard or other groups receiving the same data feed.
However, due to resource constraints uninterrupted coverage was not obtained. Overall data outages were minimal on the order
less than a day per month and because random and affect all areas uniformly do not has a significant effect on the integrity
of the data. Also as stated on the USCG NAIS website AIS data is not representative of all vessel traffic and USCG NAIS receivers
do not fully cover the entire extent of this study area. Please take time to understand both of these limitations.
Citation
Title Commercial Vessel Density October 2009-2010 AIS UTM19
Earth Science > Human Dimensions > Environmental Governance/Management
thesaurus name >
Title Global Change Master Directory (GCMD) Science Keywords
Location keywords:
United States
Location keywords:
Continent > North America > United States Of America
thesaurus name >
Title Global Change Master Directory (GCMD) Location Keywords
dataCenter
Keywords
DOC/NOAA/NOS/OCM > Office of Coastal Management, National Ocean Service, NOAA, U.S. Department of Commerce
thesaurus name >
Title Global Change Master Directory (GCMD) Data Center Keywords
publication Date
2017-04-24
Edition 8.5
project
Keywords
MarineCadastre
purpose:
To support coastal and ocean planning and other activities pursuant to the Energy Policy Act, Coastal Zone Management Act,
Magnuson-Stevens Fishery Conservation and Management Act, National Environmental Policy Act, Rivers and Harbors Act and the
Submerged Lands Act.
Resource language:
eng; US
Resource progress code:
completed
Resource Maintenance Information
maintenance or update frequency:
notPlanned
Constraints on resource usage:
Legal Constraints
Access Constraints
otherRestrictions
use constraint:
otherRestrictions
Other constraints
Access Constraints: None | Use Constraints: These data are intended for coastal and ocean use planning. Not for navigation.
| Distribution Liability: These data are intended for coastal and ocean use planning. Not for navigation.
description 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.
processing agent contact
-
processor
individual Name NOAA Office for Coastal Management
description 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.
processing agent contact
-
processor
individual Name NOAA Office for Coastal Management
source description
Source Contribution: 2010 Automatic Identification System (AIS) vessel count data for UTM Zone19N which provided information
regarding vessel counts derived from AIS data at 1 kilometer square grids. | Type of Source Media: electronic mail system
source citation
Title AIS Vessel Count - 2010
publication Date
2012-07-01
Resource extent
Temporal Extent
2009-10
2010-10
source
source description
Source Contribution: NATIONWIDE AUTOMATIC IDENTIFICATION SYSTEM | Type of Source Media: online
evaluation Method Description
The attributes in this dataset are believed to be accurate.
AbsoluteExternalPositionalAccuracy
name Of Measure Horizontal Positional Accuracy
evaluation Method Description
Maximum scale of intended use is 1:80,000.
Completeness Commission
name Of Measure Completeness Report
evaluation Method Description
Spatial and attribute properties are believed to be complete, although attribute information has been simplified. Geometric
thresholds from original data are preserved. No tests have been completed for exhaustiveness.
ConceptualConsistency
name Of Measure Conceptual Consistency
evaluation Method Description
These data are believed to be logically consistent. Geometry is topologically clean.
Use Constraints: Disclaimer - While every effort has been made to ensure that these data are accurate and reliable within
the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions
in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed
or implied, nor does the fact of distribution constitute such a warranty.
Metadata contact
-
resourceProvider
organisation Name
Office for Coastal Management
Contact information
Telephone
Voice
Address
2234 South Hobson Avenue, Charleston, SC, 29405-2413