Arizona Imagery Server
Status: complete
Partners:
Instructions on Using the Imagery Server
The Arizona Imagery Server is a map service provided by ArcIMS. There are three ways to access the Imagery Server:
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In ESRI ArcMap
- In ArcMap, click the Add Data button and in the Add Data dialog, select "GIS Servers."
- Select "Add ArcIMS Server."
- In the Add ArcIMS Server dialog, the URL you will use is http://imagery.azmap.org
- Click OK to accept. This will close out the Add ArcIMS Server dialog.
- You should now see imagery.azmap.org listed in the Add Data dialog. Double click it to expand it.
- Select the Arizona service.
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As an OGC Web Map Service (WMS)
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In a stand-alone online map viewer
Flight Dates and Metadata: Click here for Flight dates and
metadata files.
Description:
The Arizona Imagery Server project addresses the need for timely and accurate digital orthoimagery. Organizations
employing GIS place a great deal of value on digital orthoimagery, as this source of imagery is useful for
extracting new geospatial information from the imagery as well as providing context to existing geospatial data.
Despite the utility of using digital orthoimagery in GIS, many organizations do not have the capacity to acquire
and store the imagery. Imagery of this type tends to demand a substantial outlay of funding and requires a large
amount of disk storage space.
Issues with Existing Imagery
At present, access to current high quality imagery is limited due to the high cost of acquiring the data and
the storage requirements for large datasets. The project proposes consolidating in one place statewide digital
orthoimagery and other imagery as it becomes available, the design and development of a customized Internet mapping
service for distribution of imagery to state, regional, and local users, and the training of both data providers
and system users. Documentation will be produced for management and use of the Internet mapping service and
evaluation will be conducted for determination of long-term project maintenance and needs, standards and processes.
Currently, digital orthoimagery is stored by organizations in one of two ways: on networks and on hard media.
In 2002 the Arizona State Land Department acquired compressed digital orthoimagery across the entire state.
This set of imagery has been duplicated and distributed in CD sets to a number of State agencies, county organizations,
and university departments. What is more, the imagery contained in this dataset has the following issues:
- The existing imagery is out of date. The imagery in this dataset was compiled from digital orthoimagery flown between 1992 and 1999.
- The existing imagery is compressed, which reduces the quality and by extension the usability of the imagery.
- The existing imagery is mosaicked in half-degree blocks. This means that individual digital orthoimagery, which generally cover approximately 1/16 degree of latitude, are mosaicked into blocks covering 1/2 degree of latitude, covering a substantially larger area. Despite the compression, each half-degree tile is a 250MB file, making data transfer by means other than hard media difficult.
- The existing imagery has been replicated and distributed many times. Each time the full set of CDs is duplicated, staff time is required to set up and manage the duplication process, in addition to time spent labeling and packaging the CDs.
- The imagery is in a format that is not compatible with Internet map server software in the current server environment. The imagery in their compressed format is not directly readable by Land Department's Internet map server software and would require additional server software specifically for serving this compressed file format. The server is only available on Windows platform servers. The Land Department currently does not use Windows servers.
New Sources of Imagery
The U.S. Bureau of Census is in the midst of a multi-year project to improve the spatial accuracy of two of their large
databases, the Master Address File and the Topologically Integrated Geographic Encoding and Referencing system (TIGER).
As part of this improvement process, new natural color 1-meter digital orthoimagery has been collected over 12 of the 15
counties in Arizona (Cochise, Maricopa, and Pima Counties were excluded). Triathlon, Inc. has been contracted to collect
this data but retains all reuse and redistribution rights as an incentive within the program. The US Geological Survey
(USGS) has obtained the release of this data into the public domain in order to satisfy its orthoimagery program goals of
making current data available to other governmental agencies and the public. Triathlon, Inc has offering to release the data
into the public domain for $2.32 per square mile.
The Arizona State Cartographer's Office (SCO) and USGS have focused on the development of partnerships with other government
agencies in order to leverage other sources of funding to acquire this new orthoimagery. The SCO has coordinated the
collection of additional funds from other governmental agencies for this purpose. Additional funds provided to Triathlon, Inc.
from Federal and State will be applied toward releasing the data into the public domain beginning December 2005. The target
funding for imagery acquisition is $184,000, which must be met by October 1, 2005.
Once acquired, the new imagery will be stored in a relational database management system (RDBMS) that is accessed by an Internet map server. The
Internet map server provides a means by which desktop GIS applications and web applications using Open GIS Consortium Web Mapping
Service (WMS) protocols can access the imagery without requiring a local copy of the data. The proposed system will
provide the imagery in smaller pieces, thus saving network bandwidth over storing and using the imagery locally. This is
accomplished in two ways. First, the RDBMS is able to deliver only that data which is needed by the client application
(whereas file-based data tends to be delivered en-masse to the client, regardless of if only a small portion of that data
will be viewed and used). Second, the Internet map server provides the imagery in JPG, GIF, or PNG format. Since the imagery itself is
stored in tagged image format (TIF), transferring the data as in a smaller image format substantially reduces bandwidth
usage.
The SCO will work with the USGS, State and other agencies to develop additional data repositories and portals. The purpose
of this is to store appropriate redundant copies of the imagery for security and maintenance purposes. This may also be
necessary for the efficient use of the data by participating agencies.
Other Datasets
Existing DOQQs, DRGs, NED shaded relief products, and other DOI, Agriculture, state and local imagery, which require
storage in a RDBMS to be efficiently displayed in an Internet map server, may be added to the portal over time.
Integration with The National Map and Geospatial One-Stop
Participation with the USGS for integration of the Arizona Imagery Server with The National Map and Geospatial
One-Stop will assure several things.
- The data will meet national standards.
- The data may be accessed for Homeland Security purposes and by the public.
- The imagery, and other data, that is hosted through an agreement with USGS, may be placed into the Public Domain.
- Other data, available from The National Map or Geospatial One-Stop, may be used with data available on the Imagery Server.
Please contact the if you have questions or
comments regarding this project.