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Long Island Sound CT 2017 Coastal 0.5-meter Orthoimagery Project
FGDC Metadata
DescriptionSpatialData StructureData QualityData SourceMetadata
+ Resource Description
Citation
Information used to reference the data.
Title: Long Island Sound CT 2017 Coastal 0.5-meter Orthoimagery Project
Originators: Quantum Spatial
Publication date: 20170824
Data type: remote-sensing image
Description
A characterization of the data, including its intended use and limitations.
Abstract:
Product: Georeferenced un-rectified stereo images, unedited rectified frames, and orthoimagery.
				Geographic Extent: Four partial counties in Connecticut, New York and Rhode Island, covering approximately 210 total square miles.
				Dataset Description: Long Island Sound CT Coastal 0.5-meter orthoimagery project called for the planning, acquisition, processing, and derivative products of imagery data to be collected at a ground sample distance (GSD) of 0.25 to 0.52 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Orthoimagery Specification, Version 1.0. The data was developed based on a horizontal projection/datum of NAD83 (2011), State Plane Connecticut, meters and vertical datum of NAVD88 (GEOID12B), meters. Imagery data was delivered as 4-band 16-bit georeferenced un-rectified stereo images in .TIF format, 4-band 16-bit unedited rectified frames in .TIF format, and 0.5-meter 4-band (RGB-NIR) 16-bit orthoimagery tiles in GeoTIFF format. Surface data used in the orthorectification process was produced in .TIF format.
				Ground Conditions: Imagery was collected in spring of 2017, while no snow was on the ground and rivers were at or below normal levels. In order to post process the imagery data to meet task order specifications and meet horizontal accuracy guidelines, Quantum Spatial, Inc. established a total of 14 control points and 23 accuracy checkpoints were used to assess the vertical accuracy of the data.
Purpose:
This project will collect imagery that maximizes the potential to delineate coastal, estuarine, and marine features. The collected imagery will aid in the long-term management and provide a framework for conservation and management across the land-sea interface. These efforts will provide important and replicable data and an information framework for ecosystem-based coastal and marine conservation planning and implementation in the Long Island Sound that can also serve as a model for other estuaries. It was created to current imagery data for the U.S. Fish and Wildlife Service (FWS) and the cooperation with University of Rhode Island’s Environmental Data Center (RIEDC).
Data Type
How the data are represented, formatted and maintained by the data producing organization.
Data type: remote-sensing image
Time Period of Data
Time period(s) for which the data corresponds to the currentness reference.
Date: 20170628
Currentness reference:
ground condition
Status
The state of and maintenance information for the data.
Data status: Complete
Update frequency: None planned
Key Words
Words or phrases that summarize certain aspects of the data.
Theme:
Keywords: 0.5 meter orthoimage, rectified photograph, rectified image, orthophoto, natural color orthophoto, orthoimage, image map
Keyword thesaurus: None
Place:
Keywords: US
Keyword thesaurus: U.S. Department of Commerce, 1995, Countries, dependencies, areas of special sovereignty, and their principal administrative divisions, Federal Information Processing Standard (FIPS) 10-4): Washington, D.C., National Institute of Standards and Technology.
Place:
Keywords: RI
Keyword thesaurus: U.S. Department of Commerce, 1987, Codes for the Identification of the States, the District of Columbia and the outlying areas of the United States, and associated areas (Federal Information Processing Standard (FIPS) 5-2): Washington, D.C., National Institute of Standards and Technology.
Place:
Keywords: Connecticut, Middlesex County, New London County, New York, Suffolk County, Rhode Island, Washington County
Keyword thesaurus: None
Data Access Constraints
Restrictions and legal prerequisites for accessing or using the data after access is granted.
Access constraints:
None
Use constraints:
None. However, users should be aware that temporal changes may have occurred since this data set was collected and that some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data.
+ Spatial Reference Information
Horizontal Coordinate System
Reference system from which linear or angular quantities are measured and assigned to the position that a point occupies.
Coordinate System Details
Grid coordinate system
Grid coordinate system name: State Plane Coordinate System 1983
State Plane Coordinate System:
SPCS xone identifier: 0600
Lambert Conformal Conic:
Standard parallel: 41.2
Longitude of central meridian: -72.75
Latitude of projection origin: 40.83333333333334
False easting: 304800.6096
False northing: 152400.3048
Planar Coordinate Information
Planar coordinate encoding method: row and column
Coordinate representation:
Abscissa resolution: 0.5
Ordinate resolution: 0.5
Planar distance units: meter
Geodetic model
Horizontal datum name: North American Datum of 1983 (2011)
Ellipsoid name: Geodetic Reference System 80
Semi-major axis: 6378137.0
Denominator of flattening ratio: 298.257222101
Spatial Domain
The geographic areal domain of the data that describes the western, eastern, northern, and southern geographic limits of data coverage.
Bounding Coordinates
In Unprojected coordinates (geographic)
BoundaryCoordinate
West-72.6576841783536 (longitude)
East-71.7792757642501 (longitude)
North41.4388218800626 (latitude)
South40.9675610063786 (latitude)
+ Data Structure and Attribute Information
Overview
Summary of the information content of the data, including other references to complete descriptions of entity types, attributes, and attribute values for the data.
Entity and attribute overview:
Four band orthoimagery is organized in four color bands or channels which represent the red, green, blue (RGB), and near infrared (IR) portions of the spectrum.  Each image pixel is assigned a quadruplet of numeric values, one for each color band. Void areas along the project boundary of the quarter quads have value of 0 (black). Numeric values range from 0 to 255.
Entity and attribute detailed citation:
U.S. Department of the Interior, U.S. Geological Survey, 1996, Standards for Digital Orthophotos: Reston, VA.
Direct spatial reference method: Raster
+ Data Quality and Accuracy Information
General
Information about the fidelity of relationships, data quality and accuracy tests, omissions, selection criteria, generalization, and definitions used to derive the data.
Logical consistency report:
All GeoTIFF tagged data and image file sizes are validated using commercial GIS software to ensure proper loading before being archived. This validation procedure ensures correct physical format and field values for tagged elements. Seamlines and tile edges are visually inspected. Seamline mismatches are corrected unless the overall displacement is less than one pixel.
Completeness report:
Orthoimages are visually inspected for completeness to ensure that no gaps or image misplacements exist within and between adjacent images. These images are derived by mosaicking multiple images to ensure complete coverage. Source imagery is cloud free.
Attribute Accuracy
Accuracy of the identification of data entities, features and assignment of attribute values.
Attribute accuracy report:
Radiometry is verified by visual inspection of the digital orthophoto. Slight systematic radiometric differences may exist between adjacent orthoimage files; these are due primarily to differences in source image capture dates and sun angles along flight lines. These differences can be observed in an image's general lightness or darkness when it is compared to adjacent orthoimage file coverages. Tonal balancing may be performed over a group of images during the mosaicking process which may serve to lighten or darken adjacent images for better color tone matching.
Positional Accuracy
Accuracy of the positional aspects of the data.
Horizontal accuracy report:
The project specifications require that horizontal be computed for orthoimagery files. The required accuracy is: 1 meter RMSEx and RMSEy, derived according to NSSDA. The RMSEx and RMSEy were tested with 19 of 23 checkpoints. The checkpoints were distributed throughout the project area and were surveyed using GPS techniques. Values from the orthoimagery were measured for the x,y location of each check point. Horizontal positions interpolated from the orthoimagery were then compared to the horizontal values of the surveyed control points. Accuracy has been tested to meet 1 meter or better as defined by the National Standards for Spatial Data Accuracy (NSSDA).
Horizontal positional accuracy assessment:
Accuracy values
0.207
Explanation:
Tested 0.207 meters RMSEx as defined by the National Standards for Spatial Data Accuracy (NSSDA). The RMSEx of the orthoimage was calculated using 19 checkpoints.
0
Explanation:
Tested 0.282 meters RMSEy as defined by the National Standards for Spatial Data Accuracy (NSSDA). The RMSEy of the orthoimage was calculated using 19 checkpoints.
Vertical accuracy report:
There is no vertical component for orthophotos.
+ Data Source and Process Information
Data Sources
Information about the source data used to construct or derive the data.
Data source information
CONTROL
Title: GPS Photo Control Survey
Originators: Quantum Spatial, Inc.
Publication date: 2017
Data type: vector digital data and tabular data
Media: online
Source contribution:
Quantum Spatial performed a geodetic control survey in support of the digital orthophoto production project. A total of 14 control points and 35 photo identifiable objects and pre-flight targeting was used to provide ground based photo control. Please see the survey report for more information.
Date: 20170628
Currentness reference:
ground condition
PHOTO
Title: Georeferenced Single Frames
Originators: Keystone Aerial Surveys, Inc.
Publication date: 2017
Data type: remote-sensing image
Media: external hard drive
Source contribution:
Aerial imagery was acquired using DMC I large format cameras with a flight design that included a total of 184 exposures in 5 flight lines. Aerial imagery was supplemented with the simultaneous acquisition of airborne GPS/IMU data, which captured the ground coordinate for the nadir point of each photograph. Aerial imagery was exposed at an altitude of 15,000 feet above mean terrain.
Date: 20170628
Currentness reference:
ground condition
AT
Title: Aerotriangulation
Originators: Quantum Spatial
Publication date: 2017
Data type: model
Media: online
Source contribution:
Softcopy aerotriangulation was performed utilizing the airborne GPS/IMU data, GPS ground control and image coordinate measurements allowing the direct computation of the exterior orientation parameters for each image of the project.
Date: 2017
Currentness reference:
ground condition
DEM
Title: DEM
Originators: USGS
Publication date: 2017
Data type: raster digital data
Media: online
Source contribution:
Digital elevation data provided from the national elevation dataset for use in developing digital ortho imagery.
Date: 2016
Currentness reference:
publication date
Process Steps
Information about events, parameters, tolerances and techniques applied to construct or derive the data.
Process step information
Process Step 1
Process description:
Imagery Acquisition: Digital aerial imagery was obtained using a large format Z/I DMC I equipped with Airborne GPS/IMU. A total of 5 flight lines with 184 frames were collected in the summer of 2017 in multi-spectral (RGB-IR) 12-bit format. The 0.5-meter imagery was acquired at an altitude above mean terrain of 16,000 feet to yield a pixel resolution suitable for photogrammetric mapping and orthophoto production. The imagery was collected under conditions free from clouds and cloud shadows, smoke, fog, haze, light streaks, snow, ice on water bodies, flooding, excessive soil moisture, and foliage. Imagery was collected during low tide windows, during low turbidity conditions, and little to no surface wind (less than 10 mph) or waves. In order to minimize shadow conditions, and solar glint/glare, imagery was obtained during the period of the day when the sun angle was between 25 and 55 degrees. The imagery consisted of blue, green, red, and infrared bands. Imagery for the photogrammetric mapping and digital orthophotos was captured according to the USGS Contract No. G16PC00016, Task Order Number: G17PD00636 regarding, snow, haze and cloud cover, and modified as appropriate to accommodate the requirements specific to DMC I technologies and as specified in this scope of work.
Process date: 2017
Data Source used
RAWs
Data Source produced
Georefs
Process Step 2
Process description:
Control Point Collection: A total of 35 ground based photo control points were established throughout the project area using a combination of conventional and GPS survey methods in order to support softcopy aerotriangulation and photogrammetric mapping meeting the accuracies specified in this Scope of Work. Ground control collection followed requirements set forth in USGS Contract No. G16PC00016, Task Order Number: G17PD00636, and were modified as appropriate to accommodate the specifications related to ABGPS collection specific to these end photogrammetric mapping requirements. Please see the survey report for more information.
Process date: 2017
Data Source used
Geodetic control
Data Source produced
Control
Process Step 3
Process description:
Aerotriangulation: Softcopy aerotriangulation was performed on this dataset. The airborne GPS/IMU data, GPS ground control, and image coordinate measurements were utilized to allow the direct computation of the exterior orientation parameters for each image frame to support the photogrammetric process and orthophoto production.
Process date: 2017
Data Source used
ABGPS
Control
RAWs
Data Source produced
AT
Title: Aerotriangulation
Originators: Quantum Spatial
Publication date: 2017
Data type: model
Media: online
Source contribution:
Softcopy aerotriangulation was performed utilizing the airborne GPS/IMU data, GPS ground control and image coordinate measurements allowing the direct computation of the exterior orientation parameters for each image of the project.
Date: 2017
Currentness reference:
ground condition
Process Step 4
Process description:
Surface Creation: This process involved the development of seamless topographic landform elevation dataset utilizing existing elevation data to support the production of digital orthophotography that meet or exceed required orthophoto horizontal accuracy. The topographic features included a grid of elevation points and may include break lines that define ridges, valleys, edge of water, transportation features and abrupt changes in elevation. The final DEM is suitable for orthophoto production only (not suitable for contour generation). The DEM is used to then generate a Triangulated Irregular Network (TIN) to support orthophoto production.
Process date: 2017
Data Source used
DEM
Title: DEM
Originators: USGS
Publication date: 2017
Data type: raster digital data
Media: online
Source contribution:
Digital elevation data provided from the national elevation dataset for use in developing digital ortho imagery.
Date: 2016
Currentness reference:
publication date
LiDAR
Data Source produced
DEM
Title: DEM
Originators: USGS
Publication date: 2017
Data type: raster digital data
Media: online
Source contribution:
Digital elevation data provided from the national elevation dataset for use in developing digital ortho imagery.
Date: 2016
Currentness reference:
publication date
Process Step 5
Process description:
Orthoimagery Processing: Utilizing all four bands [blue (B), green (G), red(R), and infrared (IR)] digital orthorectification was performed using bilinear interpolation algorithms resulting in a spatial and radiometric transformation of the digital image from line/sample space into the NAD83 (2011) State Plane Connecticut, US survey feet. The interior and exterior orientation parameters from the aerotriangulation process were used to project each pixel into the ground coordinate system, while the ortho grade DEM/DTM was used to correct for relief displacement. Radiometric correction software and techniques were used to create orthophoto files that minimize the appearance of image seams and without loss of feature signature. Orthophotos are checked for geometric accuracy, image quality, and are tonally balanced to produce a uniform contrast and tone across the entire project. The individual overlapping orthophoto frames were mosaicked together. The ortho photos meet a horizontal accuracy of 1 meter or less at 95% confidence level when compared to higher accuracy check points based on NSSDA testing standards.
Process date: 2017
Data Source used
Georefs
AT
Title: Aerotriangulation
Originators: Quantum Spatial
Publication date: 2017
Data type: model
Media: online
Source contribution:
Softcopy aerotriangulation was performed utilizing the airborne GPS/IMU data, GPS ground control and image coordinate measurements allowing the direct computation of the exterior orientation parameters for each image of the project.
Date: 2017
Currentness reference:
ground condition
Control
DEM
Title: DEM
Originators: USGS
Publication date: 2017
Data type: raster digital data
Media: online
Source contribution:
Digital elevation data provided from the national elevation dataset for use in developing digital ortho imagery.
Date: 2016
Currentness reference:
publication date
Data Source produced
Orthos
+ Metadata Reference
Metadata Date
Dates associated with creating, updating and reviewing the metadata.
Last updated: 20170824
Metadata Point of Contact
Contact information for the individual or organization responsible for the metadata information.
Organization: Quantum Spatial
Phone: 859-277-8700
Fax: 859-277-8901
Hours of service: Monday through Friday 8:00 AM to 5:00 PM (Eastern Time)
Instructions:
If unable to reach the contact by telephone, please send an email. You should get a response within 24 hours.
Address type: mailing and physical
Address:
523 Wellington Way
City: Lexington
State or Province: KY
Postal code: 40503
Country: USA
Metadata Access Constraints
Restrictions and legal prerequisites for accessing or using the data after access is granted.
Access constraints:
None.
Use constraints:
None.
Metadata Security Information
Handling restrictions imposed on the metadata because of national security, privacy or other concerns.
Security classifiction system: None.
Security classification: Unclassified
Security handling: NONE
Metadata Standards
Description of the metadata standard used to document the data and reference to any additional extended profiles to the standard used by the metadata producer.
Standard name: FGDC Content Standard for Digital Geospatial Metadata
Standard version: FGDC-STD-001-1998
FGDC Plus Metadata Stylesheet
Stylesheet: FGDC Plus Stylesheet
File name: FGDC Plus.xsl
Version: 2.3
Description: This metadata is displayed using the FGDC Plus Stylesheet, which is an XSL template that can be used with ArcGIS software to display metadata. It displays metadata elements defined in the Content Standard for Digital Geospatial Metadata (CSDGM) - aka FGDC Standard, the ESRI Profile of CSDGM, the Biological Data Profile of CSDGM, and the Shoreline Data Profile of CSDGM. CSDGM is the US Federal Metadata standard. The Federal Geographic Data Committee originally adopted the CSDGM in 1994 and revised it in 1998. According to Executive Order 12096 all Federal agencies are ordered to use this standard to document geospatial data created as of January, 1995. The standard is often referred to as the FGDC Metadata Standard and has been implemented beyond the federal level with State and local governments adopting the metadata standard as well. The Biological Data Profile broadens the application of the CSDGM so that it is more easily applied to biological data that are not explicitly geographic (laboratory results, field notes, specimen collections, research reports) but can be associated with a geographic location. Includes taxonomical vocabulary. The Shoreline Data Profile addresses variability in the definition and mapping of shorelines by providing a standardized set of terms and data elements required to support metadata for shoreline and coastal data sets. The FGDC Plus Stylesheet includes the Dublin Core Metadata Element Set. It supports W3C DOM compatible browsers such as IE7, IE6, Netscape 7, and Mozilla Firefox. It is in the public domain and may be freely used, modified, and redistributed. It is provided "AS-IS" without warranty or technical support.
Instructions: On the top of the page, click on the title of the dataset to toggle opening and closing of all metadata content sections or click section links listed horizontally below the title to open individual sections. Click on a section name (e.g. Description) to open and close section content. Within a section, click on a item name (Status, Key Words, etc.) to open and close individual content items. By default, the Citation information within the Description section is always open for display.
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