On Demand Geospatial Image Dissemination
Geospatial imagery provides current information defense and intelligence personnel, first responders, and other tactical users need to make mission-critical decisions. The challenge is getting this data to them quickly and easily. These end users frequently operate in environments where bandwidth is limited and networks are slow. They don’t have the time to wait for data ‘bricks’ to be shipped to the field or for large image libraries to be downloaded to forward-deployed servers. By the time these resources arrive, they are often out of date. Tactical users need the most recently collected imagery in order to attain the latest situational awareness to help guide decision making.
One solution to the geospatial image delivery problem is to deploy high-performance, secure image delivery and management systems that incorporate JPEG 2000 technology. JPEG 2000 is an ISO standard (ISO/IEC 15444) for image compression and coding. JPIP is the protocol used for browsing JPEG 2000 images. With this technology, only selected regions of an image have to be moved from the server to the client for the end user to gain critical information and save valuable time. Repeated requests from the client to the server and progressive rendering of the image provide more data as the user zooms and pans in the image, yet only a small amount of the total image size is typically required to deliver actionable intelligence to the field. The movement of the image data from the server to the client is referred to as JPIP streaming.
For example, let’s suppose I’m trying to determine if a bridge in Nashville is still standing after the Cumberland River has reached the high water stage. The latest image of the area on a server I can access 4 hours old. It’s been compressed from 2.2 GB to 400 MB with JPEG2000. I’m in the field using a laptop with a poor connection where it will take two hours to download the compressed image. My server is JPIP-enabled, and I have a JPIP-enabled client, so I access the image on the server and request that it be JPIP streamed to my client. I have an overview in less than 1 minute, and with two more requests, initiated by moving and clicking my pointing device, I’m zoomed in on the bridge in question and can see that it is still standing and operational. My original view downloaded 0.45% of the overall image, or 1.7 MB, and with a couple of zooms and pans, I’ve downloaded only 1.35% of the image, or 5.2 MB of data. With JPIP tools available, I’ve been able to determine, in less than 5 minutes, that my planned route to deliver emergency supplies is feasible, and I’m ready to head out on my mission. Now that’s timely actionable intelligence!
Figure 1 – Image of Nashville and the Cumberland River loaded into a JPIP viewer at 1:32 resolution (1.7 MB of 400 MB). The blue lines are highway feature data overlaid on the image.
Figure 2 - Zoomed in to 1:1 resolution on a bridge in upper left of image (4.8 MB of 400 MB). I’ve determined that the bridge is still operational with less than 5 MB of image data downloaded to my local system.