This blog is maintained by GeoStor staff from the AGIO

Tuesday, September 22, 2009

ArcGIS Image Server Extension- Discussion

AGIO staff have been discussing the addition of the Image Server Extension to the GeoStor infrastructure. We would like to hear your thoughts.

Why
Several cities and/or counties in the state of Arkansas have acquired 1 foot and six inch ortho photography. They are interested in making the data publicly available via GeoStor (thank you). AGIO staff believe this will be a growing trend and want to be prepared to distribute the data in a useful and timely manner.

Issue
1) The data is provided in multiple projections and coordinate systems. While this is perfectly acceptable, it proves to be a challenge on several fronts when creating/combining services and providing the data as a clip, zip, ship

2) File sizes for the 1 foot and 6 inch data are large. Several have had issues downloading the data from the ftp site. The increased resolution generates a clip that generally exceeds the 2GB limit. Though other formats do support larger file sizes, there is still the download issue (discussed above).

3) Currently, a number of ortho data sets are stored in multiple locations (SDE/FTP). This results in duplicative (actually more due pyramids) disk requirements. Side note- disk isn't cheap regardless of what has been said in the past. GeoStor currently host roughly 10TB of imagery (SDE/FTP combined). This number is excpected to grow by X with the additional of more high resolution data.

4) The current process to get the data published to all the various services is time intensive (often even months). Bench mark test in other states have demonstrated processing times are dramatically reduced from months to days.

Possible Solution
ArcGIS Image Server has been implemented successfully in several other states. The product would provide the ability for the data to be stored in a single location on the FTP. Image services would actually be generated from the files on the FTP disk. This would provide for the opportunity to provide additional image services for historic ortho imagery.

Known Impact
The following are a list of impacts that we thought of. We feel sure there are likely others and are interested in hearing from you.
1) All current image service URLS would change. This would require those with saved connections to reconnect.

2) GeoStor Staff would have to change paths in a number of applications. We can live with that if we move forward.

3) Capability to download high resolution orthos via clip, zip, ship would discontinue. 1-meter statewide orthos remain available for clip, zip, ship. Users can obtain a significant area of 1-meter data.

We would like to hear from you. Have you used image server? Would changing the url paths greatly hammper your work? Other thoughts or questions?

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