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

iPhone Madness

Posted by Dave Smith On 6/30/2007 10:58:00 AM 5 comments

Yesterday, I was offered an iPhone, out of the blue. Yea, it's really cool, has an incredible interface, is power-packed with features, and just amazing technological innovations. But... I remain skeptical, I just don't share the enthusiasm that Peter Batty and others are demonstrating. Just a few things I have found thus far:


  • Maps, but no GPS. Huh? No apparent map APIs for us technogeeks who would seek to leverage it with other GIS capabilities. I'd just as soon run my mobile navigation software, along with ArcPad and other goodies...

  • Runs OSX, but it's not really OSX - It's stripped down and locked down so you can't use OSX software, can't use 3rd-party software, can't develop for it.

  • Security - Apple's smug arrogance that they are invulnerable to hacks, viruses and everything really does not sit well with me. It's a function of many things - the "get big evil Micro$oft" syndrome among hackers, market share, accessibility of development tools, and other things, not so much that Apple is in actually any more secure.

  • When you're not connected to the internet via WiFi, you get AT&T Edge - at 40kbps, that's slower than dial-up. Granted, they are upgrading to 80kbps...

  • And so on...
Maybe I will pass this time around, and instead wait for the next-generation iPhone. For the interim, I might prefer to go with a GPS-integrated Windows Mobile SmartPhone instead.

Get It Surveyed?

Posted by Dave Smith On 6/30/2007 10:03:00 AM 1 comments

I was amazed to see the articles in the news about the border fence debacle, where construction evidently went full-tilt along the US-Mexico border to construct a fence to prevent illegal immigration, following 120-year-old barbed wire strands, and without any apparent proper surveying research, and construction stakeout.


Evidently there are legal monuments spaced along the border, tall metal or concrete markers managed by the International Boundary and Water Commission, jointly operated by the US and Mexican government, but in constructing the fence, they evidently failed to do their due dilligence, and in fact the fence was revealed to be encroaching into Mexican territory. Certainly historic fence lines can have some meaning and significance as boundary evidence and as lines of possession in certain circumstances, but in this circumstance, particularly where an international boundary is concerned, I am frankly disturbed that proper survey work went by the wayside.

Technology Workers, H1B Visas and Controversy

Posted by Dave Smith On 6/29/2007 04:22:00 PM 1 comments

There have been a number of news stories circulating about the H1B visas and overseas technology workers finding employment in the US:



A fraud aspect of it stems from the appearance that employers are going out of their way to deny Americans jobs - more details here:



There are a number of additional videos and clips on YouTube and others relating to this...

I don't think that I have any problem whatsoever with foreign developers coming here in and of itself - I know and work with a lot of very wonderful and talented people from overseas.

What concerns me on one side is the pure profit motive of industry, and on the other side, I am also concerned by the protectionist and xenophobic attitude of some others, and so on. However even these seem to be stuck in the weeds and shallow water - there is also a bigger picture that needs to be examined -for example if Americans cannot find gainful employ in technology sectors, it creates many other cascading impacts and disincentives - and this in turn begins to undermine technology curricula at schools and universities, it impacts research and innovation, and so on. And ultimately, all of these may also adversely impact profit.

Gains and losses should be balanced judiciously.


Life isn't just about cold hard cash.

As of June 4, 2007, the USGS will be releasing selected Landsat 7 image data of the United States through the Web (glovis.usgs.gov or earthexplorer.usgs.gov). These data are of high quality with limited cloud cover (referred to as the Landsat ETM+ SLC-off L1T Standard Product).

This Web-enabled distribution of new and recently acquired data is a pilot project for the Landsat Data Continuity Mission (LDCM), currently projected for launch in 2011.

The project will allow the Landsat data user community to help refine the distribution system planned for the upcoming LDCM. Each scene will be registered to the terrain, or “ortho-rectified,” prior to being placed on the Web. Copies of these data will also be available on CD or DVD at the cost of reproduction.

Landsat data have proven useful for a wide range of applications. From disaster monitoring after Hurricane Katrina and the Indonesian tsunami to global crop condition analysis, Landsat data are being used by scientists around the world.

The Web-based distribution system will allow the user community easier access to Landsat 7 data. The pilot project will be carefully examined. Customer response will be evaluated and their insight will influence the future distribution system.

Rachel Kurtz, PhD
Data Acquisition Manager, Acting
Landsat Project

USGS EROS
Land Remote Sensing Program
Sioux Falls, SD 57198

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...

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