Surveying, Mapping and GIS

While everyone else is off to Where, et cetera - I'm going off to the EPA GIS Workgroup meeting in New York City...

I was just in a conversation with a friend of mine - I found that he's been wrestling with some homebrew code for managing large aerial photos - and the usual issues of performance, memory management, caching, and multiresolution data came up. A number of useful resources in the Open Source community are available in that arena, and I thought I would share some of them:

OSSIM - Open Source Software Image Map

http://www.ossim.org/

From the OSSIM site:

OSSIM is a high performance software system for remote sensing, image processing, geographical information systems and photogrammetry. It is an open source software project maintained at http://www.ossim.org/ and has been under active development since 1996. The lead developers for the project have years of experience in commercial and government remote sensing systems and applications.

OSSIM has been funded by several US government agencies in the intelligence and defense community and the technology is currently deployed in research and operational sites. The name OSSIM is a contrived acronym (Open Source Software Image Map) that is pronounced “awesome” – the acronym was established by our first government customer.

Another interesting effort ongoing is the Open Aerial Map project, spearheaded by the prodigiously prolific MetaCarta map ninja and OpenLayers/TileCache developer Christopher Schmidt:

OAM - Open Aerial Map

http://openaerialmap.org/

From the OAM site:

This project is an attempt to gather data from various free and open aerial imagery datasources around the world, and use them to create a single, coherent open world view.

If you are interested in seeing your data here, please email crschmidt@crschmidt.net.

Both of these sites contain code repositories, documentation, and other community resources are available, such as IRC chat channels.

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

In the Amazon Mechanical Turk effort to analyze imagery for potential clues in the disappearance of Jim Gray, I thus far managed to log 185 units of 5 images each, the count was well over 4000 when I started, and the last one I completed said 1 remaining. It was plainly evident that I had a great deal of company throughout this effort.

Certainly there were several instances of images where boats, along with their associated wakes, could be seen in the images, however a great many were difficult to read, with a great deal of reflectance, cloud cover, and so on.

It will be interesting to see what the next steps are - whether more data or additional passes will be offered up through Mechanical Turk, and if any of what participants identified will ultimately be able to correlated to other activity in the vicinity, or indeed provide clues to Gray's location.

UPDATE: Some additional images from a NASA aircraft have been posted to Mechanical Turk - see the following link: http://www.mturk.com/mturk/preview?groupId=J0XZ58STDWJZ5QY4F9M0

I have also located a blog site operated by the folks who have been organizing this effort: http://openphi.net/tenacious/
- They have posted quite a few updates and insights into the nature of the imagery and ongoing effort

Just received this announcement from a colleague:

National Land Cover Database (NLCD 2001)
The U.S. Geological Survey, on behalf of the interagency Multi-Resolution Land Characteristics Consortium (MRLC), is pleased to announce the availability of NLCD 2001 products for the conterminous United States. These products are web enabled for download from the MRLC website at www.mrlc.gov. NLCD 2001 products include 21 classes of land cover, percent tree canopy and percent urban imperviousness at 30 m resolution derived from Landsat imagery. NLCD 2001 will support a wide variety of users, institutional sectors and local- to national-scale applications with this updated land-cover data. Alaska, Hawaii, and Puerto Rico will be completed by December of 2007, which will then represent the first compilation of nationwide land cover ever produced at 30-meter resolution.

Great news for a wide variety of applications - I was just looking at a watershed application, myself, where this data will fit quite nicely.

I did a quick check, it's not yet visible in the MRLC map viewer, however the data is available via FTP - visit the Multi-Resolution Land Characteristics site: http://www.mrlc.gov/