Data Quality Information provides a general assessment of the quality
of a dataset.
2. Data Quality Information (Mandatory if Applicable)
CONTAINS:
2.1 Attribute Accuracy (Mandatory
if Applicable)
2.2 Logical Consistency Report (Mandatory)
2.3 Completeness Report (Mandatory)
2.4 Positional Accuracy (Mandatory
if Applicable)
2.5 Lineage (Mandatory)
2.6 Cloud Cover (Optional)
NOTE: This guide only provides information concerning optionality at the section level and top level elements within each section. Keep in mind that the optionality of a section or compound element always takes precedence over the elements that it contains, and if deemed applicable, then the optionality of its subordinate elements is to be interpreted. Refer to either the FGDC Metadata Workbook, Version 2.0 or Section 2 of the USGS's "Image Map of the Content Standard for Digital Geospatial Metadata", a graphical representation of the Standard for rules concerning optionality.
2.1 Attribute Accuracy
Definition: An assessment of the accuracy of the identification
of the entities and assignments of attribute values in the dataset.
This metadata element contains the following sub-elements:
2.1.1 Attribute Accuracy Report
Definition: An explanation of the accuracy of the
identification of the entities and assignments of values in the data
set and a description of the tests used.
Format: Free text.
2.1.2 Quantitative Attribute Accuracy Assessment
Definition: A value assigned to summarize the accuracy
of the identification of the entities and assignments of attribute
values in the dataset and the identification of the test that yielded
the value.
2.1.2.1 Attribute Accuracy Value
Definition: An estimate of the accuracy of the
identification of the entities and assignments of attribute values
in the dataset.
Format: Free text.
Example:
Attribute Accuracy Value: Unknown
2.1.2.2 Attribute Accuracy Explanation
Definition: The identification of the test that
yielded the Attribute Accuracy Value.
Format: Free text.
2.2 Logical Consistency Report
Definition: An explanation of the fidelity
of the relationships in the dataset and tests used.
Format: Free text.
Example:
Logical Consistency Report: Polygons intersecting the neatline are
closed along the border. Segments making up the outer and inner boundaries
of a polygon tie end-to-end to completely enclose the area. Line segments
are a set of sequentially numbered coordinate pairs. No duplicate features
exist nor duplicate points in a data string. Intersecting lines are
separated into individual line segments at the point of intersection.
Point data are represented by two sets of coordinate pairs, each with
the same coordinate values. All nodes are represented by a single coordinate
pair which indicates the beginning or end of a line segment. The neatline
is generated by connecting the four corners of the digital file, as
established during initialization of the digital file. All data crossing
the neatline are clipped to the neatline and data within a specified
tolerance of the neatline are snapped to the neatline. Tests for logical
consistency are performed by WAMS verification software (USFWS-NWI).
2.3 Completeness Report
Definition: Information about omissions, selection
criteria, generalization, definitions used, and other rules used to
derive the dataset.
Format: Free text.
Example:
Completeness Report: All photo-interpretable wetlands are mapped.
In the treeless prairies, 1/4 acre wetlands are mapped. In forested
areas, small open water and emergent wetlands are mapped. In general,
the minimum mapping unit is from 1 to 3 acres depending on the wetland
type and the scale and emulsion of the source aerial photography. In
regions of the country where evergreen forested wetlands predominate,
wetlands smaller than 3 acres may not be mapped. Thus, a detailed on-the-ground
and historical analysis of a single site may result in a revision of
the wetland boundaries established through photographic interpretation.
In addition, some small wetlands and those obscured by dense forest
cover may not be included in this dataset.
2.4 Positional Accuracy
An assessment of the accuracy of the positions of spatial
objects. This metadata element contains the following sub-elements:
2.4.1 Horizontal Positional Accuracy
An estimate of accuracy of the horizontal positions of
the spatial objects.
2.4.1.1 Horizontal Positional Accuracy Report
Definition: An explanation of the accuracy of
the horizontal coordinate measurements and a description of the
tests used.
Format: Free text.
Example:
Horizontal Positional Accuracy Report: Accuracy of these digital
data (if not digitally revised), is based upon the use of source
graphics which are compiled to meet National Map Accuracy Standards
(NMAS). NMAS horizontal accuracy requires that at least 90% of points
tested are within 0.02 inches of the true position. The digital
data are estimated to contain a horizontal positional error of less
than or equal to 0.003 inches standard error in the two component
directions relative to the source graphic. NMAS vertical accuracy
requires that at least 90% of well defined points tested be within
one half contour interval of the correct value.
2.4.1.2 Quantitative Horizontal Positional Accuracy Assessment
Numeric value assigned to summarize the accuracy of the
horizontal coordinate measurements and the identification of the
test that yielded the value.
2.4.1.2.1 Horizontal Positional Accuracy Value
Definition: An estimate of the accuracy of the
horizontal coordinate measurements in the dataset expressed in
(ground) meters.
Format: Real.
2.4.1.2.2 Horizontal Positional Accuracy Explanation
Definition: The identification of the test that
yielded the Horizontal Positional Accuracy Value.
Format: Free text.
2.4.2 Vertical Positional Accuracy
An estimate of accuracy of the vertical positions of the
spatial objects.
2.4.2.1 Vertical Positional Accuracy Report
Definition: An explanation of the accuracy of
the vertical coordinate measurements and a description of the tests
used.
Format: Free text.
Example:
Vertical Positional Accuracy Report: Accuracy of these digital
data (if not digitally revised), is based upon the use of source
graphics which are compiled to meet National Map Accuracy Standards
(NMAS). NMAS vertical accuracy requires that at least 90% of well
defined points tested be within one half contour interval of the
correct value.
2.4.2.2 Quantitative Vertical Positional Accuracy Assessment
Numeric value assigned to summarize the accuracy of the
vertical coordinate measurements and the identification of the test
that yielded the value.
2.4.2.2.1 Vertical Positional Accuracy Value
Definition: An estimate of the accuracy of the
vertical coordinate measurements in the dataset expressed in
(ground) meters.
Format: Real.
2.4.2.2.2 Vertical Positional Accuracy Explanation
Definition: The identification of the test that
yielded the Vertical Positional Accuracy Value.
Format: Free text.
2.5 Lineage
Information about the events, parameters, and source data
which constructed the dataset, and information about the responsible
parties. This metadata element contains the following sub-elements:
2.5.1 Source Information
List of sources and a short discussion of the information
contributed by each.
2.5.1.1 Source Citation
Reference for a source dataset.
Guidelines and examples for applying the metadata sub-elements for
Source Citation are contained in Section
8 (Citation Information).
2.5.1.2 Source Scale Denominator
Definition: The denominator of the representative
fraction on a map (for example, on a 1:24,000-scale map, the source
scale denominator is 24000).
Format: Integer; Source Scale Denominator > 1
Example:
Source Scale Denominator: 24000
2.5.1.3 Type of Source Media
Definition: The medium of the source dataset.
Format: Free text.
Example:
Type of Source Media: paper
Type of Source Media: stable-base material
Type of Source Media: microfiche
Type of Source Media: microfilm
Type of Source Media: audiocassette
Type of Source Media: chart
Type of Source Media: filmstrip
Type of Source Media: transparency
Type of Source Media: videocassette
Type of Source Media: videodisc
Type of Source Media: videotape
Type of Source Media: physical model
Type of Source Media: computer program
Type of Source Media: disc
Type of Source Media: cartridge tape
Type of Source Media: magnetic tape
Type of Source Media: online
Type of Source Media: CD-ROM
Type of Source Media: electronic bulletin board
Type of Source Media: electronic mail system
2.5.1.4 Source Time Period of Content
Time period(s) for which the dataset corresponds to the
ground.
Guidelines and examples for applying the metadata sub-elements for
Source Time Period of Content are contained in Section 9 (Time Period).
2.5.1.4.1 Source Currentness Reference
Definition: The basis on which the Source Time
Period of Content information of the source dataset is determined.
Format: Free text.
Example:
Source Currentness Reference: publication date
Source Currentness Reference: ground condition
2.5.1.5 Source Citation Abbreviation
Definition: Short-form alias for the source citation.
Format: Free text.
Example:
Source Citation Abbreviation: USGS1
Source Citation Abbreviation: NWR3
2.5.1.6 Source Contribution
Definition: Brief statement identifying the information
contributed by the source to the dataset.
Format: Free text.
Example:
Source Contribution: Aerial photo from which wetlands spatial
and attribute information are interpreted.
2.5.2 Process Step
Information about a single event.
2.5.2.1 Process Description
Definition: An explanation of the event and related
parameters or tolerances.
Format: Free text.
Example:
Process Description: NWI maps are compiled through manual photo interpretation
of NHAP or NAPP aerial photography, supplemented by soil surveys
and field checking of wetland photo signatures. Delineated wetland
boundaries are manually transferred from interpreted photos to USGS
7.5 minute topographic quadrangle maps and then manually labeled.
Quality control steps occur throughout the photo interpretation,
map compilation, and map reproduction processes.
2.5.2.2 Source Used Citation Abbreviation
Definition: The Source Citation Abbreviation
of a dataset used in the processing step.
Format: Source Citation Abbreviations from the Source Information entries for the dataset.
2.5.2.3 Process Date
Definition: The date when the event was completed.
Format: Free date.
Example:
Process Date: 2002
Process Date: January 2002
Process Date: 2002-01-01
Process Date: 2002/01/01
Process Date: 20020101
Process Date: Unknown
Process Date: Not Complete
2.5.2.4 Process Time
Definition: The time when the event was completed.
Format: Free time.
Example:
Process Time: 15:11:45
2.5.2.5 Source Produced Citation Abbreviation
Definition: The Source Citation Abbreviation of
an intermediate dataset that (1) is significant in the opinion
of the data producer, (2) is generated in the processing step, and
(3) is used in later processing steps.
Format: Source Citation Abbreviations from the Source Information entries for the dataset.
2.5.2.6 Process Contact
The party responsible for the processing step information.
Guidelines and examples for applying the metadata sub-elements for
Process Contact are contained in Section
10 (Contact Information).
2.6 Cloud Cover
Definition: Area of a dataset obstructed by clouds,
expressed as a percentage of the spatial extent.
Format: Integer; range from 0 to 100.
Example:
Cloud Cover: 50
Cloud Cover: Unknown