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CIESIN's Guide to FGDC Compliant Metadata

2. Data Quality Information

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

CIESIN's Guide to FGDC Compliant Metadata

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