I love playing with maps. I will attempt to share what I learn and the new things that I am doing with GIS systems
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Simple thoughts, hard processes
Posted 03-18-2008 at 05:04 PM by lfdmike
I've been doing some tweaking of my mapplication.
The ancient Aloha NOAA dll would render an threat zone and a confidence zone. The difference between the 2 is that the confidence zone swept out a wider arc- compensating for variations in wind direction and other inaccuracies. Never can be too safe with the hazardous materials
I created a new algorithm for my mapplication, to add in that confidence area besides the original threat zone. I based mine off of the Emergency Response Guide instructions, which have a swept area equal to the downwind range. Not too hard- yeah right...
That accomplished, I added in the ability to relocate the release point. Not every chemical spill will be at the end of my driveway. So a right click now will set the center point, and plot the zones.
Something else that was added in along the way was USNG display. It is not something we are currently using, but in the future that could be an interoperability thing to work out, so I'll do it now- and that automatically displays along with the lat & long of the release point
Comparison? I found me a nasty chemical in the database known as phosgene. It was a chemical weapon circa World War I. The hazmat highlights of a large (>50 gallon) spill:
1. 2500 ft / 765 meters isolation
2. 7 mile / 11 km protection zone downrange
I used the standalone version of Aloha to create a plot. I also created the same plot using my algorithms plotted into Virtual Earth. I did a copy-paste-resize in good old MS Paint and then overlayed the Aloha plots ontop of mine. The Aloha is colored red, mine is yellow. The black grid is from Aloha, and the spacing is 2 km on them. Yes, it cannot plot our shape as it is too big. I think they are pretty close, but you can judge for yourselves
One of the tricks here is the inverted colors outside of the threat zone. It is a practical application of John @ SoulSolutions implementation of IE Image Filter
This second plot is a little smaller. It would have been for the satellite that failed. Luckily the US Navy was able to shoot it down, otherwise this would have been the isolation zones for Downtown Milwaukee. The specs on it are 50/800 meter isolation zones, and a southwest wind, inverted colors on a road map
The ancient Aloha NOAA dll would render an threat zone and a confidence zone. The difference between the 2 is that the confidence zone swept out a wider arc- compensating for variations in wind direction and other inaccuracies. Never can be too safe with the hazardous materials
I created a new algorithm for my mapplication, to add in that confidence area besides the original threat zone. I based mine off of the Emergency Response Guide instructions, which have a swept area equal to the downwind range. Not too hard- yeah right...
That accomplished, I added in the ability to relocate the release point. Not every chemical spill will be at the end of my driveway. So a right click now will set the center point, and plot the zones.
Something else that was added in along the way was USNG display. It is not something we are currently using, but in the future that could be an interoperability thing to work out, so I'll do it now- and that automatically displays along with the lat & long of the release point
Comparison? I found me a nasty chemical in the database known as phosgene. It was a chemical weapon circa World War I. The hazmat highlights of a large (>50 gallon) spill:
1. 2500 ft / 765 meters isolation
2. 7 mile / 11 km protection zone downrange
I used the standalone version of Aloha to create a plot. I also created the same plot using my algorithms plotted into Virtual Earth. I did a copy-paste-resize in good old MS Paint and then overlayed the Aloha plots ontop of mine. The Aloha is colored red, mine is yellow. The black grid is from Aloha, and the spacing is 2 km on them. Yes, it cannot plot our shape as it is too big. I think they are pretty close, but you can judge for yourselves
One of the tricks here is the inverted colors outside of the threat zone. It is a practical application of John @ SoulSolutions implementation of IE Image Filter
This second plot is a little smaller. It would have been for the satellite that failed. Luckily the US Navy was able to shoot it down, otherwise this would have been the isolation zones for Downtown Milwaukee. The specs on it are 50/800 meter isolation zones, and a southwest wind, inverted colors on a road map
