Alaska Statewide Orthoimagery Mosaic
Quick links:
- Map of the 2009 and 2010 coverage: JPEG map image - 383 kB
- Shapefile showing the 2009, 2010 source scenes and 2010 ortho tiles
- Additional download instructions.
- Pilot delivery sneak preview
Overview
The Alaska Statewide Digital Mapping Initiative is producing a new statewide orthomosaic, which will provide complete multispectral coverage of the state at 2.5-meter spatial resolution. This satellite image mosaic will be the first consistent, high-resolution, high-accuracy, digital orthoimagery base layer ever produced across the entire state of Alaska.
The orthoimage will be produced to 1:24,000 National Map Accuracy Standards (NMAS) with a CE90 of 12.2-meters. This means that more than 90% of the points will be within 12.2 meters or better of their true location on the Earth. This is an accuracy improvement of at least three times for most existing maps of Alaska. Three statewide mosaics will be delivered: color infrared (CIR), psuedo-natural color, and panchromatic (grayscale). The full land area of Alaska with a 1-kilometer buffer around the coastline and border.
The orthomosaic will be complete by 2014 and include data collected over five seasons, 2009-2013.
The source data is licensed for use by the US public sector and academia at no additional cost. Others can purchase licenses to use the data at a reduced cost. When available, the orthomosaices will be publicly available to all US users via Open Geospatial Consortium web services. Please see the license file EULA for details. Contact us for details.
The statewide orthoimagery contract was awarded to Aero-Metric, Inc. Subcontractor Spot Image is providing the source imagery from their SPOT 5 satellite. Subcontractor Fugro Earthdata is performing the image processing, orthorectification, and mosaicing. As prime contractor, Aero-Metric is responsible for overall project management, provision of control and DEMs, and quality assurance. The specifications for the contract can be found in the RFP document.
Schedule
- Fall 2010: initial delivery, acceptance, and distribution of 2009 and 2010 source data scenes
- Winter 2010: processing to orthomosiacs of source data
- Spring 2011: first blocks of orthomosiac delivered and published via web services
- Summer 2011: collection of new source scenes
- 2012 … 2014 : repeat collection, processing, and delivery cycle.
- Summer 2013: last collection season
- June 30, 2014: statewide orthomosaic is complete.
Source data
The source data is the SPOT5 leve1 1A panchromatic and multispectral scene pairs that will be used to generate the orthomosaic products. Preview imagery has been created, but these georeferenced browse images are not map products. The browse has been rubbersheeted into approximate locations and not orthorectified or controlled, so they should only be used for previewing the data. See the SPOT5 leve1 1A page for more details.
The first year delivery of source data (2009 and 2010) happened as a large delivery of several hundred scenes that took significant time to review and accept in bulk. Acceptance has was completed and the source scenes added to the browse site. In the future years, with smaller, continuous deliveries and well-established procedures, the goal is to have the source scenes available within 30 days of reception.
Please read these download instructions regarding how to get access to the SPOT 5 Level 1A satellite imagery data.
Map showing SPOT 5 source data accepted from 2009 and 2010 Alaska seasons.
Map showing foot print of SDMI’s ortho imagery and DEM collections for 2010.
The shapefile showing data footprints has the coverages, acquisition dates, scene identifier, and link to the download page on the browse site.
What will it look like?
How is this data an improvement over the existing orthoimagery available statewide–Landsat 7 pan sharpened to 15-meters?
The current statewide color base layer (Landsat 7 natural color, 15-meter spatial resolution):
The new statewide color base layer (SPOT 5 psuedo-natural color, 2.5-meter spatial resolution):
The current statewide panchromatic layer (Landsat 7, 15-meter spatial resolution):
The new statewide color base layer (SPOT 5, 2.5-meter spatial resolution):
Download instructions describe how to get access to the SPOT 5 Level 1A satellite imagery data.
Please contact us if you have questions.
