Safeguarding GIS Data through Metadata
Christopher Cialek
& Nancy Rader
Minnesota Geospatial
Information Office
September 2004, updated May 2014
What’s Metadata?
If you had two cans without labels, which would you eat?
Without a label, how would you know which was tuna and which was cat food?
Cat Food?
Tuna?
By the end of the Workshop . . .
Understand what metadata is; appreciate its value
Become familiar with metadata standards
Create your own metadata records
Use a search engine to find data
Know where to go for help
You will:
From: stacey stark <stark-stacey@ To: MNPLAN.MNPLANPO(rader-n) Date: 9/21/98 12:09PM Subject: Quaternary Geology layer Nancy, I am trying to learn as much as I can about the sources of the Quaternary geology layer of the MGC100 data. I do not know who or where the data was transformed / processed from the EPPL7 format – if you have any information, that would be very helpful. (log indicates user name whpa?). I am also wondering if the coverage I have might be the scanned polygon coverage before it was converted to EPPL6? The coverage name used to be qgeo - but I don't recognize the user. Would you have information? I hope I am not too much of a pain, I talked to MGS. They have never processed a polygon coverage of Quaternary geology in this area. Thank you very much. Stacey Stark GIS Specialist EPA Mid-Continent Ecology Division
From: "Tim Ogg" To: <[email protected]> Date: 8/ 3/ 00 11:53AM Subject: Re: soils documentation & status chart Hi Nancy - I have a Washington Co cover that I think came f rom the county or the SWCD. I t was residing on the computer of a former employee so I don't know exactly where it came from. The attributes on it are all wrong. Polygons are severely mislabeled all over the place. I intend to get a "good" copy f rom the county or SWCD. Where’s the best place to look? Thanks Tim
From: stacey stark <stark-stacey@ To: 'Nancy Rader' Date: Thursday, January 15, 2004 12:46 PM Subject: RE: FW: PLS QQ metadata -----Original Message----- I now know what I need to about the data. Thanks for all your help. Tracking down this info has been kind of a nightmare. After this experience I can testify to the NEED for data to have metadata along with it. It gets frustrating when you don't know what it is or where it came from. Thanks again for the help jeff
What’s Metadata?
“the information that makes data sets understandable, usable and
sharable.”
International Standards Organization
FDA Food LabelWe often use metadata without knowing it -- even a food label is an example of metadata!
What’s Metadata?
Structured format
Specific content
Necessary information
What’s Metadata?
Search metadata to find resources
in the library
Library community has developed metadata
systems to describe books
– Dublin Core
Allows you to
search by title,
author, subject…
What are Metadata Used For?
MANAGING DATABASES
COMPARING DATA SETS
FACILITATING DATA SHARING
PROVIDING TECHNICAL SPECS
FINDING DATA
Standards
Content Standard for Digital Geospatial Metadata (CSDGM)
– Established by the FGDC in 1994
– Foundation standard for the NSDI
– “Mandatory” for federal agencies
– www.fgdc.gov/metadata/geospatial-metadata-standards#csdgm
Standards
Minnesota Geographic Metadata Guidelines (MGMG)
– Derived from the federal standard in 1998
– Simplified, but retains all required fields
– Became state standard in 1999
– www.mngeo.state.mn.us/committee/standards/mgmg/metadata.htm
Standards
ISO 19115 Geographic Information: Metadata
– International geospatial metadata standard
– More information: www.fgdc.gov/metadata/geospatial-metadata-standards#fgdcendorsedisostandards
Metadata Structure Examples
mandatory
mandatory, if applicable
optional
LINEAGE
Source Information
Source Citation
Source Time Periodof Content
Citation Information
Source Scale
Type of Source Media
Time Period Info
Source Currentness
Source Contribution
Source Citation Abbrev
Process Step
Process Date & Time
Source Used Citation
Process Description
Source Produced
Process ContactContact Information
CSDGM
LINEAGE
MGMG
LINEAGE
Statement
Process Step
Description
Rationale
Processor
Date & Time
Source
Description
Scale
Spatial Reference Sys
Source Citation
Source Extent
Source Step
ISO
TheMinnesotaGeographic Metadata Guidelines
The MGMG
SUBSET OF A FEDERAL STANDARD
MADE UP OF SEVEN SECTIONS
DRIVES WEB SEARCH TOOLS
USED BY OVER 100 ORGS IN MN
MN STANDARD; FGDC RECOGNIZED
Seven Sections of the Minnesota Geographic Metadata Guidelines
Minnesota State Guideline 17-1.2http://www.gis.state.mn.us/stds/metadata.htm
1Identification
2Data
Quality
3Spatial DataOrganization
4Spatial
Reference
5Entity andAttribute
6Distribution
7MetadataReference
Originator Attribute Accuracy Native Data SetEnvironment
HorizontalCoordinate Scheme
Entity and AttributeOverview
Publisher Metadata Date
Title Logical Consistency GeographicReference (Tabular)
Ellipsoid Entity and AttributeDetailed Citation
Publication Date Metadata ContactInformation
Identifier (optional) Completeness Spatial Object Types Horizontal Datum &Units
DistributorInformation
Metadata StandardInformation
Abstract Positional Accuracy Tiling Scheme Resolution Distribution Liability
Purpose Lineage Altitude Datum &Units
Transfer Format
Content Date Source Scale Depth Datum & Units Transfer Size
Currentness If Raster Ordering Instructions
Progress If Geographic Online Linkage
Maintenance andUpdate Frequency
If UTM
Spatial ExtentDescription
If State Plane
BoundingCoordinates
If County Coordinate
Keywords If User SpecifiedProjection
Constraints If Other
Contact Information
Browse GraphicInformationAssociated DataSets
Abstract
Purpose
1Identification
Originator
Title
Identifier (optional)
Content Date
Currentness
Progress
Maintenance andUpdate FrequencySpatial ExtentDescription
BoundingCoordinates
Keywords
Constraints
Contact Information
Browse GraphicInformationAssociated DataSets
A Walk Through the Guidelines
Originator: name of organization or individual that developed the data
Title: name by which the data set is known
Abstract
Purpose
1Identification
Originator
Title
Identifier (optional)
Content Date
Currentness
Progress
Maintenance andUpdate FrequencySpatial ExtentDescription
BoundingCoordinates
Keywords
Constraints
Contact Information
Browse GraphicInformationAssociated DataSets
TITLE– Too cryptic:
niclcpy3– Too general:
Landuse– Acronyms:
Wisconsin DOPs– Too detailed:
Wetland Polygon Coverage Overlay for St. Cloud (USGS Quad)
– Just right (includes theme, area, date): Minnesota Telecommunications
Service Area Boundaries, 2007
Abstract
Purpose
1Identification
Originator
Title
Identifier (optional)
Content Date
Currentness
Progress
Maintenance andUpdate FrequencySpatial ExtentDescription
BoundingCoordinates
Keywords
Constraints
Contact Information
Browse GraphicInformationAssociated DataSets
A Walk Through the Guidelines
Abstract: summary of what’s in the data setThis land cover data set was derived from 30
meter resolution LANDSAT Thematic Mapper
(TM) satellite imagery. Classification is divided
into 15 classes with source imagery dates
ranging from September 1991 to August 1996.
Both a raster and a vector version are
available.
Purpose: why the data set was developedLand use planning, natural resource
monitoring
Abstract
Purpose
1Identification
Originator
Title
Identifier (optional)
Content Date
Currentness
Progress
Maintenance andUpdate FrequencySpatial ExtentDescription
BoundingCoordinates
Keywords
Constraints
Contact Information
Browse GraphicInformationAssociated DataSets
A Walk Through the Guidelines
Time Period of Content: single date that best describes when the data are current08/2004
Currentness: text describing what the Time Period date is referring to, e.g., range of dates of aerial photographyDate of source imagery (LANDSAT-5 TM,
bands 3, 4, and 5) ranges from September 20,
1991 to August 30, 1996.
Abstract
Purpose
1Identification
Originator
Title
Identifier (optional)
Content Date
Currentness
Progress
Maintenance andUpdate FrequencySpatial ExtentDescription
BoundingCoordinates
Keywords
Constraints
Contact Information
Browse GraphicInformationAssociated DataSets
A Walk Through the Guidelines
Spatial Extent: description of the geographic area covered
(Lyon County, Minnesota)
Bounding Coordinates: the extreme north, south, east and west limits of coverage expressed in latitude and longitude values
W -95.4 E -89.5 N 49.4 S 45.5
Abstract
Purpose
1Identification
Originator
Title
Identifier (optional)
Content Date
Currentness
Progress
Maintenance andUpdate FrequencySpatial ExtentDescription
BoundingCoordinates
Keywords
Constraints
Contact Information
Browse GraphicInformationAssociated DataSets
A Walk Through the Guidelines
Keywords: words or phrases that summarize the theme and location of the data set, together with the name of any formal list of keywords (thesaurus)
Too general: GIS, layer, surveyJust right: Feedlot, animal agriculture,hog
Constraints: any restrictions to the access or use of the data set
Access: Due to increased security measures taken after 9/11/01, this data set is no longer available online.
Use: . . . right to use these data for any internal purpose
Abstract
Purpose
1Identification
Originator
Title
Identifier (optional)
Content Date
Currentness
Progress
Maintenance andUpdate FrequencySpatial ExtentDescription
BoundingCoordinates
Keywords
Constraints
Contact Information
Browse GraphicInformationAssociated DataSets
A Walk Through the Guidelines
Contact Information: the person who can answer questions about the content or development of the data set
Abstract
Purpose
1Identification
Originator
Title
Identifier (optional)
Content Date
Currentness
Progress
Maintenance andUpdate FrequencySpatial ExtentDescription
BoundingCoordinates
Keywords
Constraints
Contact Information
Browse GraphicInformationAssociated DataSets
A Walk Through the Guidelines
Browse Graphic: a sample illustration of the data set
Abstract
Purpose
1Identification
Originator
Title
Identifier (optional)
Content Date
Currentness
Progress
Maintenance andUpdate FrequencySpatial ExtentDescription
BoundingCoordinates
Keywords
Constraints
Contact Information
Browse GraphicInformationAssociated DataSets
A Walk Through the Guidelines
Associated Data Sets: information about other, related data sets that may be of interest
If you’re interested in this data set, here are others that may also interest you. NOT a list of source materials (those are described in Lineage).
For information on other air photos available for Minnesota, see www.mngeo.state.mn.us/chouse/airphoto/
A Walk Through the Guidelines
Attribute Accuracy: qualitative or quantitative explanation of how accurately features in the data set have been described, including procedures used to assess accuracy (examples: field-checking, checkplots, frequency counts to find invalid codes)
2Data
Quality
Attribute Accuracy
Logical Consistency
Completeness
Positional Accuracy
Lineage
Source Scale
A Walk Through the Guidelines
Completeness: information about selection criteria, omissions, generalization, etc.
2Data
Quality
Attribute Accuracy
Logical Consistency
Completeness
Positional Accuracy
Lineage
Source Scale
EXAMPLE: Geographic exclusion
“Data was not available for Smith Township.”
A Walk Through the Guidelines
Completeness: information about selection criteria, omissions, generalization, etc.
2Data
Quality
Attribute Accuracy
Logical Consistency
Completeness
Positional Accuracy
Lineage
Source Scale
EXAMPLE: Categorical Exclusion
“Municipalities with population
under 1000 not included.”
A Walk Through the Guidelines
Positional Accuracy: an explanation of what’s known about the horizontal and vertical accuracy of the data set (can be qualitative or quantitative)
Qualitative example:
2Data
Quality
Attribute Accuracy
Logical Consistency
Completeness
Positional Accuracy
Lineage
Source Scale
Data was collected in the field and plotted on a variety of base maps. Archaeological properties visited in the past 30 years are located on USGS maps. Almost all site locations are accurate to the quarter section. Most site locations are accurate to within a quarter-quarter section. Site boundaries are poorly defined, as are site centroids.
Minnesota State Historic Preservation Office Archaeological Inventory
A Walk Through the Guidelines
Positional Accuracy: an explanation of what’s known about the horizontal and vertical accuracy of the data set
Quantitative example:
2Data
Quality
Attribute Accuracy
Logical Consistency
Completeness
Positional Accuracy
Lineage
Source Scale
Using the National Standard for Spatial Data Accuracy, this data set tested 1 foot horizontal accuracy at 95% confidence level.
City of Minneapolis (from Positional Accuracy Handbook)
A Walk Through the Guidelines
Lineage: information about the sources of data used to construct the data set and processing steps applied
2Data
Quality
Attribute Accuracy
Logical Consistency
Completeness
Positional Accuracy
Lineage
Source Scale
LINEAGE RECIPE2
DataQuality
Attribute Accuracy
Logical Consistency
Completeness
Positional Accuracy
Lineage
Source Scale
1. Source Information
Data set reference
Scale
Media
Time period of content
Source contribution
Source Metadata reference
2. Processing Step
Process description
software used
organization doing the processing
Process date
3. Miscellaneous Notes
A Walk Through the Guidelines3
Spatial DataOrganization
Native Data SetEnvironmentGeographicReference (Tabular)
Spatial Object Types
Tiling Scheme
This section no longer used.
A Walk Through the Guidelines4
SpatialReference
HorizontalCoordinate SchemeEllipsoid
Horizontal Datum &Units
Resolution
Altitude Datum &UnitsDepth Datum & Units
If Raster
If Geographic
If UTM
If State Plane
If County Coordinate
If User SpecifiedProjectionIf Other
A Walk Through the Guidelines
Entity & Attribute Overview: description of the information content of the data set: the features it represents (entities) and details about them (attributes). An entity might be road and the attributes that describe it might include interstate, 6 lanes, concrete.
Entity & Attribute Detailed Citation: reference to other sources of detailed information on the content of the data set; pointer to a data dictionary
5Entity andAttribute
Entity and AttributeOverviewEntity and AttributeDetailed Citation
A Walk Through the Guidelines
Examples: Land Use Codes5
Entity andAttribute
Entity and AttributeOverviewEntity and AttributeDetailed Citation
Useless:
212223
Slightly Better:
AGRICULTURAL LAND
21 - Cultivated Land 22 - Pasture Land23 - Transitional Agricultural Land
A Walk Through the GuidelinesMuch Better:
AGRICULTURAL LAND
21 - Cultivated Land Cultivated land includes those areas under intensive cropping or rotation, including periods when a parcel may be fallow. It represents land planted to forage or cover crop. The units exhibit linear or other patterns associated with current or relatively recent tillage.
22 - Pasture LandLand in active pasture use. This class was discontinued and combined into 23.
23 - Transitional Agricultural LandThis category includes areas that show evidence of past tillage but do not now appear to be continuously cropped or in a crop rotation. Parcels in this unit include fields that are idle or abandoned and may or may not have been planted to a cover crop. In addition to displaying some evidence of past tillage, they usually are relatively uniform in vegetation.
A Walk Through the Guidelines
Publisher: organization or individual that distributes the data set
Distributor Information: person who can answer questions about the distribution of the data set
Distribution Liability: statement of any liability assumed by the distributor
Limitations
Warranty
Liability
Redistribution Conditions
Data Delivery Terms
6Distribution
Publisher
Publication Date
DistributorInformation
Distribution Liability
Transfer Format
Transfer Size
Ordering Instructions
Online Linkage
A Walk Through the Guidelines
Ordering Instructions: instructions for obtaining the data set. If applicable, instructions for acquiring data through Online Linkage element below
Online Linkage: (optional) when the data set is available online, this is the link to the Internet site where it can be downloaded
6Distribution
Publisher
Publication Date
DistributorInformation
Distribution Liability
Transfer Format
Transfer Size
Ordering Instructions
Online Linkage
A Walk Through the Guidelines
Two reports available to aid in determining
GIS data distribution policy
6Distribution
Publisher
Publication Date
DistributorInformation
Distribution Liability
Transfer Format
Transfer Size
Ordering Instructions
Online Linkage
Mapping the Risks:
Assessing the Homeland Security Implications of Publicly Available Geospatial Information
2004 RAND National Defense Research Institute http://www.rand.org/pubs/monographs/MG142.html
RAND researchers found no publicly accessible federal geospatial information deemed critical to meeting attackers’ information needs.
The researchers found only four publicly available federal databases that had information that is both useful to potential attackers and could not
be obtained from other widely available sources. The four federal databases are no longer being made public by federal agencies
A Walk Through the Guidelines
Two new reports available to aid in
determining GIS data distribution policy
6Distribution
Publisher
Publication Date
DistributorInformation
Distribution Liability
Transfer Format
Transfer Size
Ordering Instructions
Online Linkage
Guidelines for Providing Appropriate Access to Geospatial
Data in Response to Security Concerns
http://www.fgdc.gov/policyandplanning/Access%20Guidelines.pdf
A Federal Geographic Data Committee Homeland Security Working Group study investigating restrictions to geospatial data access that are
reasonable, sensible and cost effective
Purpose of a Metadata Entry Tool
Organizes metadata content
Provides help
Formats results– printed reports– webpages– Clearinghouse searches
Can it write the whole record for you?(no)
Tool
Minnesota Metadata Editor (MME)
Customized from the EPA’s metadata editor
Standalone– Requires only Microsoft .NET 3.5
– Microsoft Access is required to edit the database
More information and download:
www.mngeo.state.mn.us/chouse/mme/
How to Make this Easier…
Value metadata
Create metadata during your project
Prioritize legacy data
Use existing resources
Writing tips
Use your judgment
Share the task
Value metadata
Establish its value for yourselfand for your organization
Short-term investment long-term payoff
Metadata is no longer optional;it is part of being a GIS and IT professional
Cat Food
Create metadata during your project
When you create new data
When you change existing data
If you write metadata as you go along,at the end, it is done!
Tuna
Prioritize legacy data
What is most critical?
What are you asked about the most?
What may be lost soonest?– Information that is quickly forgotten
– Information that only one person or organization knows
Use existing resources
Guidelines and tools
Starter templates
Existing documents
Other peoples’ metadata
Writing tips
Goal: Concise but complete
Metadata records are drafts– Fill out in any order
– Modify when information changes
Get help from others– Editor
– Interviewer
OK to describe imperfections in the data– Data Quality and Purpose fields
– OK to say, “I don’t know”
Use your judgment
Some information is defined
Fixed set of choices
Fixed format
Some information is flexible
Defining data sets– Not too fine or too broad
Amount of detail– Answer the questions that you want answered
Share the task
Divide by areas of expertise
Do something…
How will you follow up after the workshop?
Imagine yourself back at your usual place of work…
Now, write down one or two specific things related to
metadata that you could do in the next week or two
Do something…
How can you follow up after the workshop?
Suggestions:
– Install one of the metadata tools on your computer
– Start documenting a data set you are currently creating
– Create your own starter template
– Use the GeoGateway to look for data you need
– Write down an obstacle and think of a way around it
– Tell a coworker about something of value you learned today
More HelpMnGeo
www.mngeo.state.mn.us/chouse/meta_help.html
FGDCwww.fgdc.gov/metadata/
Questions?
Chris Cialek– [email protected]– 651-201-2481
Nancy Rader– [email protected]– 651-201-2489
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