Identification, Selection, and Appraisal within the North Carolina Geospatial Data Archiving Project (NCGDAP)

NCSU Libraries

Steve Morris Head of Digital Library Initiatives

Digital Preservation in State Government: Best Practices Exchange 2006

Note: Percentages based on the actual number of respondents to each question 2

NC Geospatial Data Archiving Project

Partnership between university library (NCSU) and state agency (NCCGIA), with Library of Congress under the National Digital Information Infrastructure and Preservation Program (NDIIPP)One of 8 initial NDIIPP partnerships (only state project)Focus on state and local geospatial content in North Carolina (state demonstration)Tied to NC OneMap initiative, which provides for seamless access to data, metadata, and inventoriesObjective: engage existing state/federal geospatial data infrastructures in preservation

Note: Percentages based on the actual number of respondents to each question 3

Targeted Content: Vector Data

Note: Percentages based on the actual number of respondents to each question 4

Targeted Content: Digital Orthophotos

Note: Percentages based on the actual number of respondents to each question 5

Targeted Content: Digital Orthophotos

Note: Percentages based on the actual number of respondents to each question 6

Targeted Content: Digital Orthophotos

Note: Percentages based on the actual number of respondents to each question 7

Targeted Content: Tabular Data

Note: Percentages based on the actual number of respondents to each question 8

Targeted Content: Digital Maps

Note: Percentages based on the actual number of respondents to each question 9

Problem Scope - NC

County Digital Orthophotos88 counties with, estimated 154 flights by 2006Estimated 30 gb/flight – 4.6 TB total

County, City, COG Vector DataVariable mix of layers; some continuous update92 of 100 counties with GIS systems51 municipalities with GIS systems

State Agency Data1993 and 1998 statewide orthos – 800 gbTerabytes of vector data and other imagery17-20 TB of LIDAR data

Note: Percentages based on the actual number of respondents to each question 10

Why Formal Inventory Processes?

Alleviate “contact fatigue” on part of local agencies

20 different NC state agencies contact local agencies for data … also, federal/regional agencies

Geospatial data is complex, requiring lengthy inventory process

Must capture descriptive, technical, and administrative information related to the data

Make the inventory available as a sharable data store

Note: Percentages based on the actual number of respondents to each question 11

History of GIS Inventories (NC & US)

1997 National Geospatial Data Framework Survey 1997 Survey of GIS Data Availability for NC CountiesNC Flood Mapping Program, 2000-2001NC OneMap Data Inventory, 2003RAMONA (Random Access Metadata Tool for Online National Assessment), from March 2006

Note: Percentages based on the actual number of respondents to each question 12

RAMONA Inventory System-- From March 2006-- Nationwide (state-by-state)

Note: Percentages based on the actual number of respondents to each question 13

What do Inventories Offer?

Data Availability InformationDetailed information by data layer

Contact InformationMinimal Metadata

Descriptive, technical, administrative

Rights InformationDocument Technical Environment

Software used, formats, transfer methods

Future Data Development Plans

Note: Percentages based on the actual number of respondents to each question 14

County Digital Orthophotography Specifics

Imagery Type

21.0%

76.0%

1.5% 1.5%

Color-InfraredTrue ColorBlack & WhiteNot Sure

Maintenance Frequency

3.0%

1.5%

10.6%

7.6%

1.6%

36.4%

2.0%3.0%

10.6%

1.7%

Daily Annually Every 2 Yrs. Every 3 Yrs.Every 4 Yrs. Every 5 Yrs. As Funds Allow OtherNot Sure Not Maintained

Data Meet LRMP Specifications?

80.0%

3.1%

16.9%

Yes

No

Not Sure

Source: NC OneMap Data Inventory 2004

Note: Percentages based on the actual number of respondents to each question 15

Inventories as Source of MetadataExample: Surface Water

0%

5%

10%

15%

20%

25%

30%

Source of Data

CGIA 1:24kCGIA 1:100kUSGS 1:24k DLGUSGS 1:24k DRGPrivate ContractorDelineated from Locally-Produced OrthoElevation DataOtherNot Sure

0%

10%

20%

30%

40%

50%

60%

70%

Surface Water Attributes

Stream Name Stream ClassStream Order Stream TypeOther Not SureNone

Note: Percentages based on the actual number of respondents to each question 16

Inventories as Archive Items

Data inventories as archive items:e.g., 1997 federal survey data no longer available on FGDC website

Note: Percentages based on the actual number of respondents to each question 17

Selection Issues

Targeting data produced within the stateMost content is already at risk

Exceptions: LIDAR, county-level numeric, …

Early-Middle-Late Stage issuesMiddle stage is usually the “sweet spot”, e.g. TIFF orthophotos vs. raw images or compressed images

Also added-value products: digital maps, cartographic representation

Digital maps: extent of coverage and propensity for use in GIS factored into selection

Frequency

Note: Percentages based on the actual number of respondents to each question 18

Time series – vector dataParcel Boundary Changes 2001-2004, North Raleigh, NC

Continuously updated data: Frequency of snapshots?Different for various framework

layers?

Note: Percentages based on the actual number of respondents to each question 19

Problem:Multiple choice for: format type, coordinate system, tiling scheme

Note: Percentages based on the actual number of respondents to each question 20

Conclusion

Formal inventory processes of spatial data infrastructure help with identifying contentInventories provide data for preservation analysis (format trends, etc.)Need to select from among different formats, coordinate systems, etc.Frequency of capture for time-versioned content is a tricky issue

Note: Percentages based on the actual number of respondents to each question 21

Questions?

Contact:

Steve MorrisHead, Digital Library InitiativesNCSU LibrariesSteven_Morris@ncsu.edu

Web site: http://www.lib.ncsu.edu/ncgdap/