Confluence Retirement

Due to the feedback from stakeholders and our commitment to not adversely impact USGS science activities that Confluence supports, we are extending the migration deadline to January 2023.

In an effort to consolidate USGS hosted Wikis, myUSGS’ Confluence service is targeted for retirement. The official USGS Wiki and collaboration space is now SharePoint. Please migrate existing spaces and content to the SharePoint platform and remove it from Confluence at your earliest convenience. If you need any additional information or have any concerns about this change, please contact Thank you for your prompt attention to this matter.
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primary contacts:

John Aguinaldo, Cassandra Ladino 

Eastern Geographic Science Center

Reston, VA


Project Topic


Resources Required

Major Outcomes

Total Funding Needed

HTML5 GIS functionality for Openlayers

Coordinate with the OpenLayers lead developers on implementing client-side HTML5 compliant Canvas layer raster imagery processing that would work in any HTML5 standard compliant browser.

Candidate datasets would be land cover (National Land Cover Data, Chesapeake Bay Land Cover Data Series, Chesapeake Resource Lands Assesment Data and other raster layers for restoration/preservation priority decision making.

EGSC point of contact to coordinate with OpenGeo

•  Ability to calculate basic statistics for visible map images (e.g.
count per pixel color, total area per pixel color).

•  Ability to generate zonal statistics based on polygon features from
a vector layer - user drawn or rendered from a remote source (e.g.
display imagery "clipped" to a user drawn polygon and calculate
statistics on the output).

•  Ability to generate new raster composites from existing data
sources.  Allow pixel-based raster algebra using raw imagery or other
composites as inputs (e.g. user could view land cover data above a
certain elevation and calculate statistics on the output).

The OpenGeo team would require $22k.

EGSC requires no funding.

Benefit to FSP/Scientists/Mission Areas

  • Land Cover Change, Ecosystems
  • Would allow online raster analysis through browser technologies and avoid local data replication
  • Alternative to other web map technologies (flash)
  • Lots of potential mobile applications
  • Any raster analytic application that can benefit from dynamic visualization (i.e., instant visual feedback from user input, e.g., slider functionality).

In kind funding and work leveraged

The Land Cover Analysis Tool (LCAT) and Chesapeake Online Adaptive Support Toolkit (COAST) have been developed and provide raster analysis capability. This would improve the functionality and performance of both existing applications and potentially improve other web map based USGS projects. This is a component of a toolkit the OpenGeo will be building with substantial amounts of in kind development time.

Deliverable and its Measurable Benefit

Proposal per OpenGeo:We propose to develop a set of raster utility classes and layer types for inclusion in OpenLayers to allow for statistical analysis, manipulation, and additional rendering functionality for raster data sources.  Our deliverables will be patches for the OpenLayers development branch that include the new functionality, examples and documentation to demonstrate its use, and comprehensive unit test coverage.  Our intention is to get this newly developed functionality into the next stable release of OpenLayers.
An additional component of an HTML5 toolkit for the opensource JavaScript mapping framework OpenLayers. These tools are esspecially useful to USGS web mapping needs.

This effort will deliver a new set of classes within the OpenLayers library.  These classes will enable developers to more rapidly develop dynamic visualization because it is being done on the client with client resources (as opposed to send requests to a web service and awaiting a response as the system processes a much larger set of data).

This small investment will jump start the open source community in bringing dynamic raster processing to the web browser client via HTML5 and Javascript.  As we are seeing now in the news, this is where technology is heading as processors get faster, storage gets larger, and the browser client becomes an application framework.

There has already been some activity in the GIS community regarding work with Canvas-based raster manipulations, but so far they have been proof-of-concept demos only.  This investment will provide for an open source Canvas raster framework that will allow developers to begin implementing within their architectures and contribute further functionality.  The importance of open source should be underscored here as the same low level architectural contributions are not possible with other proprietary libraries (e.g., ArcGIS Javascript API) where the source code is "minified" and variable names are obfuscated.
In other words, this investment will be a jump start for creating a serious client-side raster processing architecture which will provide important raster functionality for the types of analytic web GIS applications built within the USGS.  This jump start will put pressure on competing Javascript mapping libraries (e.g., ArcGIS Javascript API) to provide similar functionality.

This is a seemingly innocuous investment, but it has huge rippling effects in the entire GIS community and gives USGS a rare opportunity to influence the leading edge direction of GIS technology.

Methodology (process)


  1. Develop classes for working with raster grids and composites (multi-band grids).  Develop functionality to allow for creation of rasters from existing image based layers.  Allow for raster operations to generate new grids or composites from existing grids or composites (basic pixel-based raster algebra).  Test, document, and develop examples for all new functionality.
  2. Develop a raster layer class for displaying raster grid or layer data as a normal map layer.  Test, document, and develop examples for all new functionality.
  3. Develop utilities for creating raster grids from vector data sources (this will allow zonal stats or clipping of rasters using vector data).  Test, document, and develop examples for all new functionality.
  4. Develop utilities for generating statistics from raster grids or composites.  Allow for statistics to be recalculated lazily (only when needed) and whenever data sources are updated.  Test, document, and develop examples for all new functionality.


CDI, EGSC, OpenGeo, greater FOSS4G community.