PowerPoint Presentation€¦ · Title: PowerPoint Presentation Author babs Created Date: 3/28/2013 1:19:37 PM

Generalization for Multi-Scale Representation, Display, and Delivery of The National Map of the

United States

Lawrence V. Stanislawski1, Cynthia A. Brewer2, and Barbara P. Buttenfield3

1 Center for Excellence in Geospatial Information Science (CEGIS), United

States Geological Survey (USGS), Rolla, Missouri, USA, [email protected]

2 Department of Geography, Pennsylvania State University, USA,

[email protected] 3 Department of Geography, University of Colorado-Boulder, USA,

[email protected]

Designing MRDB and Multi-Scale DCMs, Barcelona, Spain 21-22 March 2013

Outline

• The National Map of the United States

– Eight primary data themes

– US Topo Maps

– Historical Maps

– Viewer

• National Atlas®

• NHD Generalization Tools for MRDB

• Road Thinning for MRDB and Multi-Scale Display


The National Map of the United States United States policy requires that geospatial data and products developed by federal agencies be accessible for the cost of distribution.

The United States Geological Survey (USGS) has managed collaborative efforts between private, state, federal and academic partners to develop and maintain The National Map

The National Map comprises a variety of products and services that provide the Nation with access to nationally consistent base geospatial information to describe the landscape of the United States and its territories and to enable better management of resources.

The National Map includes:

• Eight (8) primary themes of geospatial data

• US Topo Maps

• Historical Maps

• The National Map Viewer


The National Map: Eight Primary Data Themes


• Land Cover – 2006 Nat. LC Database, 16 classes, 30m res.

• Structures – selected structures (e.g. schools, hospitals) from best available data (points convert to polys)

• Boundaries – States, counties, Federal and Native American lands, and incorporated areas (cities, towns)

• Hydrography - NHD, multi-scale data (some larger than 12K, most 24K, Alaska 63.360K, also complete 100K)

• Geographic Names – authoritative names for cultural and physical features (e.g., pop. places, hist. features, mountains, streams, hospitals, etc.)

• Transportation – airports, railroads, roads, and other from TomTom of North America®and US Census

• Elevation – NED, best available multi-resolution (30-m, 10-m, 3-m, and Lidar 3to1m), Alaska (all 60-m, some 30-m and 10-m, move to 5-m IFSAR), derive

• Orthoimage – 1m NAIP 3-yr cycle, higher res from others.

The National Map: US Topo Maps


• Downloadable 1:24,000-scale digital map in georeferenced portable document format (GeoPDF).

• Compiled entirely from National Map layers

• Conterminous US complete (2009 - 2012)

• Revising workflow to include additional content

• Implemented through system of customized tools and work flow with software from Esri, TerraGo, ANUDEM, and others

• ~18,000 maps produced each year with planned 3-year refresh cycle

• Local resolution NHD (12K or larger) is generalized to 24K

• Planning new map design

The National Map: Historical Maps


• All scales and editions of the maps published by the USGS since the inception of the topographic mapping program in 1884 are being scanned and made available in GeoPDF format.

• Over 170,000 GeoPDFs available for Download

CHICKASHA, OK 1904 30 MINUTE SERIES QUADRANGLE (1:125,000–SCALE) HISTORICAL TOPOGRAPHIC MAP

The National Map: Viewer


• Interactively view National Map data as map, customize the view, print a map, and download the data • Developed in partnership with Nat. Geospatial Intel. Agency (NGA) and others • Map tools: navigate, identify feature, query, measure, etc.



• Can download data or view it with OGC Web mapping services (WMS) and keyhole markup language (KML).

• Partner Web mapping services that are registered in the Geospatial One-Stop portal as online geospatial services can also be overlaid onto The National Map base map



• The Viewer image tile caches are built with 20 zoom levels, but only 15 are used (1-15), up to about 18K. Data are served dynamically at larger scales

• Over 2 million tiles needed to cover nation at all scales.

• Image tiles are compiled from National Map and National Atlas data with data appropriately thinned for each scale.

• Topographic base map and Image view caches are provided in the Viewer. Working to complete others.

• Over 90 servers host and deliver The National Map data and services

The National Atlas of the United States of America®

• Collaborative effort of several federal agencies

• Contains a range of products and services:

– Map Maker: use more than 2,400 map layers to select, display, and print your own maps

– Printable Maps: A large list of page-size printable maps (GIF, PDF) (e.g. congressional districts, satellite view, climate

– Wall Maps: available to order

– Dynamic Maps: innovative multimedia illustrations of geographic phenomena

– Articles about geography of America



• Contains a range of products and services (cont.):

– Data: Data used on the maps can be downloaded in compressed format (Vector – shapefile; geostatistical data – DBF; image – GeoTIFF).

– Metadata: extensive documentation describing each data set.

Content complies with federal standard for geospatial data. – Web map services in Open Geospatial Consortium (OGC)

protocols are available to access the more than 2,400 data layers.


The National Atlas of the United States of America® • Atlas uses datasets of a highly generalized framework

from The National Map as the cartographic base map for the thousands of thematic map layers. Data was compiled by over 20 Federal agencies

• Data available for download include layers from the following categories:



1: 1 Million-Scale base map data available for download for the United States layers from the following categories:


1: 10 Million-scale base map data available for download for North America include layers from the following categories:

Generalization Framework

Generalization

• Stratified pruning (Radical Law)

• Tailored simplification

• Multiscale symbolization

Dissemination with

The National Map

Assessment

• Cartographic evaluation

• Statistically-based metrics

• Cross-validation

Enrichment (NHD schema) Classify Catchments Land Types Density Upstream Partitions Drainage Area

Low

High

Objective: Fully automated generalization to support multiple-scale versions of USGS data (current focus on NHD)

Products

• LoD data layers

• Processing toolbox

• Graphic Products

Delineate Primary Paths

NHD Generalization Toolbox

• Enrichment • Pruning • Simplification • Validation These tools are being implemented to generalize local resolution NHD to 24K for 24K US Topo production

NHD Generalization to 1:Million-Scale (1M)

• National Atlas 1M hydrography was generalized from the 100K NHD through automated and manual procedures

• Testing ability of NHD toolbox to generalize high-res NHD to 1M in a manner that mimics what exists in the 1M National Atlas data, which allows

– Find differences and enhance databases

– Sequential updates to National Atlas

– Replace National Atlas data with integrated MRDB

Methods

• Begin with 24k HR NHD (establish local density partitions)

• Create star version 100k LoD (enrich, prune, simplify) – Simplify each density partition differentially (70m, 50m, 50m)

• Create ladder version 1M LoD – Modify automated centerline delineation algorithm to define

“primary path” which mimics 1M National Atlas flowline network (1.5% Drainage Area)

– This becomes a surrogate for network pruning

– Prune area features

– Simplify using identical parameters to existing National Atlas (500 m simplification for all density partitions)

1:100K LoD compared with Medium Res NHD

0 100 20050 Miles

0 150 30075 Kilometers

LoD Flowlines

Medium Res NHD flowlines

HUC4 subbasins

HU8 subbasins

1:1M LoD compared with National Atlas

0 100 20050 Miles


1:1M LoD compared with National Atlas Omission / Commission

0 100 20050 Miles


Summary

• Benefits of generalizing 1:1M data from 24K HR NHD – Higher accuracy source data

– Local density variations preserved in 100K and (to lesser extent) in 1M

– Automatically create feature level links for all three scales (24k source, 100K LoD, and 1M target)

• Future Work – Metric Validation using CLC and CAs, Average Segment

Displacement metrics and other measures

– Refine parameters to tailor solutions to other terrain and landscape types

Documents

PowerPoint Presentation€¦ · Title: PowerPoint Presentation Author ____ babs ____ Created Date: 3/28/2013 1:19:37 PM

PowerPoint Presentation€¦ · Title: PowerPoint Presentation Author babs Created Date: 3/28/2013 1:19:37 PM