Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Skip to content

AFSC/RACE/GAP/McConnaughey: QTC View Study- 1997- Other

Metadata Updated: April 1, 2024

In early 1996, Quester Tangent Corporation (QTC) and the National Marine Fisheries Service (NMFS) Alaska Fisheries Science Center (in Seattle) formed a strategic alliance to apply QTC seabed classification technology to the problem of groundfish habitat descriptions. The Bering Sea supports about 300 fish species, many of which are demersal species. This stock supports sizeable fisheries, as indicated by landings at the Bering Sea port of Dutch Harbor in excess of 579 million pounds in 1996 and 678 million pounds in 1999 (the highest in the U.S.). By comparison, in 1981 the landing at Dutch Harbor was 73 million pounds. This rapid increase in catch highlights the need for effective management to ensure sustainability. After connecting the QTC VIEW full waveform acquisition system (ISAH-S) to the Simrad EK-500 scientific echosounder on the NOAA ship Miller Freeman, over 9,000 miles of track line data were collected in the eastern Bering Sea between June and August 1999. The raw data consist of digital echo traces of the full water column and seabed substrate. They were collected at two frequencies, 38 kHz and 120 kHz. Based on an average rate of one ping recorded per second, approximately four million individual echoes at each frequency were obtained. The data within this raster set represent the results of processing channel 38_12, which incorporated the 38 kHz frequency data, using a reference depth of 90 meters and stacks of 50 echoes to create a single classified data point through the PCA analysis. A rasterized grid was created from each Q value and then grid stacked to allow RGB representation of each data point in continous Q- space as opposed to categorical class.

Access & Use Information

License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources

Dates

Metadata Date February 29, 2024
Metadata Created Date October 28, 2022
Metadata Updated Date April 1, 2024
Reference Date(s) (publication)
Frequency Of Update

Metadata Source

Harvested from NMFS AFSC

Additional Metadata

Resource Type Dataset
Metadata Date February 29, 2024
Metadata Created Date October 28, 2022
Metadata Updated Date April 1, 2024
Reference Date(s) (publication)
Responsible Party (Point of Contact, Custodian)
Contact Email
Guid gov.noaa.nmfs.inport:17106
Access Constraints Cite As: Alaska Fisheries Science Center, [Date of Access]: AFSC/RACE/GAP/McConnaughey: QTC View Study- 1997- Other [Data Date Range], https://www.fisheries.noaa.gov/inport/item/17106., Access Constraints: There are no legal restrictions on access to the data. They reside in public domain and can be freely distributed., Use Constraints: The United States Government shall not be held liable for improper or incorrect use of data described and/or contained herein. These data and related graphics are not legal documents and are not intended to be used as such. The Alaska Fisheries Science Center gives no warranty, expressed or implied, as to the accuracy, reliability, or completeness of these data. Spatial information may not meet National Map Accuracy Standards. The information contained in these data is dynamic and may change over time. Original data were compiled from various sources. The data are not better than the original sources from which they were derived. It is the responsibility of the data user to use the data appropriately and consistent within the limitations of geospatial data in general and these data in particular. It is strongly recommended that these data are directly acquired from an Alaska Fisheries Science Center server and not indirectly through other sources which may have changed the data in some way. Although these data have been used (processed) successfully on a computer system at the Alaska Fisheries Science Center, no warranty expressed or implied is made regarding the utility of the data on another system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data.
Bbox East Long -160.316406
Bbox North Lat 63.17572
Bbox South Lat 53.923279
Bbox West Long -178.690796
Coupled Resource
Frequency Of Update
Harvest Object Id 6d1881ab-ea77-4f14-8021-795d89abbc11
Harvest Source Id 26a29bb9-50b0-47fd-920b-edc74aa6ec76
Harvest Source Title NMFS AFSC
Licence NOAA provides no warranty, nor accepts any liability occurring from any incomplete, incorrect, or misleading data, or from any incorrect, incomplete, or misleading use of the data. It is the responsibility of the user to determine whether or not the data is suitable for the intended purpose.
Lineage unknown
Metadata Language eng
Metadata Type geospatial
Old Spatial {"type": "Polygon", "coordinates": [[[-178.690796, 53.923279], [-160.316406, 53.923279], [-160.316406, 63.17572], [-178.690796, 63.17572], [-178.690796, 53.923279]]]}
Progress completed
Spatial Data Service Type
Spatial Reference System
Spatial Harvester True
Temporal Extent Begin 1999-06-01
Temporal Extent End 1999-08-01

Didn't find what you're looking for? Suggest a dataset here.