Surveying, Mapping and GIS

Exploring all aspects of mapping and geography, from field data collection, to mapping and analysis, to integration, applications development and enterprise architecture...

  • Geospatial Technology, End to End...

    Exploring all aspects of mapping and geography, from field data collection, to mapping and analysis, to integration, applications development, enterprise architecture and policy
Showing posts with label ArcIMS. Show all posts
Showing posts with label ArcIMS. Show all posts

Seeking Web GIS Applications Developers...

Posted by Dave Smith On 8/08/2007 09:18:00 AM 1 comments

For the mashup artists, AJAX gurus, ArcIMS experts, .NET jockeys out there...
Synergist Technology Group, Inc. is currently looking for GIS web applications developers, for its Pennsylvania and Northern Virginia locations.

Requirements:

Strong background in web-based GIS applications development.


  • DHTML, CSS, and JavaScript;

  • ASP.NET, C#, VB.NET, or Java

  • ESRI ArcIMS

  • Web Services (XML, SOAP, JSON, REST, OGC)

  • Understanding of spatial databases
Desired Skills:

ArcGIS Server, Oracle Spatial query and analysis, mashups and exposure to Microsoft Virtual Earth, Google Earth, Google Maps, good documentation and communication skills.

Additionally, a background in emergency response, transportation, facilities management or environmental science may be very useful.

Applying:

Applicant must be a US Citizen or have US Permanent Resident Status

Interested applicants should respond with a current curriculum vitae and salary requirements to dsmith[@]synergist-tech.com.

Synergist Technology Group, Inc. - A Service-Disabled Veteran-Owned Small Business (SDVOSB) specializing in geospatial technology, environmental science, transportation and emergency response.

Vector Data, SOA and Scalability

Posted by Dave Smith On 6/26/2007 04:35:00 PM 3 comments

One of the things I am still trying to get my head around is scalability in vector-based web services, such as OGC Web Feature Services or ArcIMS Feature Services. Certainly with image services, one can do a lot of magic behind the scenes - such as tiling, caching, load balancing.

In many instances, an image service will suffice well, but for power users, for ad-hoc queries and analysis, the full geometry and attribute data is often needed. And in the case of a distributed enterprise, here is one place where a purely SOA-oriented approach begins to break down.

Things becomes a bit more difficult when it comes to vector geometry, as most GIS clients are still only geared toward consuming and processing vector data in one chunk.

Further, vector geometries can't well be broken into tiles without causing other breakage - polygons and linear features need to retain their topological integrity in order to work.

Yes, one can certainly cache vector feature services, provided the underlying data is relatively static, or apply constraints limiting the amount of data that one can fetch at a time, but is there any possibility, looking down the road, of utilizing more efficient serial or multiple parallel processes to rapidly and efficiently stream large and complex vector datasets?

I think there will need to be, and I don't yet see OGC, ESRI or anyone else looking at this. I'd be interested in hearing other folks' thoughts and experiences on this...

ESRI Developer Summit?

Posted by Dave Smith On 3/22/2007 08:56:00 PM 0 comments

No, I was not able to attend... Getting the occasional bits and pieces of information from the DevSummit.

For those folks who are attending, say hi to Xiuzhu Yang, a good friend of mine and very talented developer that I have been working with for the last year on EPA projects.

Another very talented guy that I cross paths with, also at the DevSummit this year is Vincent Zhuang from SAIC, author of Programming ASP.NET for ArcGIS Server.

EPA Data and TerraIMS

Posted by Dave Smith On 3/12/2007 09:18:00 PM 0 comments

I don't always post about some of the things that we are working on, and perhaps I should do so more often.

I had some mixed feelings about recently seeing the Google Maps mashup that TerraIMS recently put up, showing EPA Superfund sites in proximity to a given address.
http://www.terraims.com/webservices/superfund.php



EPA has, for many years (in some instances, dating back to 1999), already had a number of community-oriented web mapping applications which deliver a great deal of information on EPA regulated sites, EPA cleanup activities, and so on - For example, one flagship of USEPA Office of Environmental Information is the venerable Window to My Environment - which, among other things, provides a great deal of information on EPA regulated facilities, watersheds, local and state resources, and the like at a community level. Window to My Environment currently gets well in excess of 50,000 hits per day.

Another excellent application which provides a lot of detailed information on environmental cleanup activity at a local level is the USEPA's Office of Solid Waste and Emergency Response (OSWER) Cleanups In My Community application.



These are just some of the web mapping projects that I have been involved in lately - there are actually several more EPA EnviroMapper applications available at the EnviroMapper StoreFront - and we are currently in the process of overhauling the core infrastructure of these, to migrate from legacy ASP/VBScript platforms to reusable component-based design, web services, and the ability to host some of these applications in an Oracle Portal environment, and integrating MetaCarta searches, among other things. We also have been doing some preliminary explorations in making EPA data available as KML for Google Earth, presenting some of our own Google Maps mashups (similar to TerraIMS), all of which are working wonderfully thus far. Unfortunately some of these enhancements are still in prototype, and others are only available on the EPA intranet.

So what of TerraIMS? Great work they did - but my concern isn't constrained, nor in any way specific to this particular mashup. The concern I have is with the description of the effort:

The U.S. Environmental Protection Agency recently released its National Priority list of Superfund Sites in XML format. We converted the XML data and integrated it with a database and then mashed things up a bit. Users enter an address and it is geocoded on the fly, enabling a distance query to be processed against the EPA data in the database. This mashup allows anyone to quickly and easily find the nearest Superfund Sites to their home address or a location of interest.

From this description, it sounds like they essentially have performed an extract of the EPA data, have massaged and processed it, and then do their mashup. The business case isn't tremendously compelling, as these maps and data are already long available, so it appears to be a mashup just for the sake of doing a mashup.

Fortunately Superfund data isn't tremendously volatile, however it nonetheless raises the question of other potential applications, of currency, completeness and accuracy of data utilized in mashups. Herein lies potential liability. If one uses a third-party mashup as a decision support tool, they would need to know to track back to the original source to ensure that the data they are viewing in the mashup is current, complete, and accurate...

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