Archive for the ‘SAR’ Category

Search status

Friday, February 16th, 2007

Since January 28, the San Francisco police, the Coast Guard and Jim’s friends and family have conducted an extensive search to find him and his sailboat, Tenacious, off the California coast. I want to summarize the status of that search here, so that the broad volunteer community that’s done so much knows where we stand.

The Coast Guard’s air and surface search covered 132,000 square miles in the days immediately following Jim’s disappearance. This search was thorough: Planes, boats and helicopters covered much of the region repeatedly. Radio broadcast alerts were made for a week, and all marinas and harbors were canvassed repeatedly. It found no trace of Tenacious or Jim.

During the Coast Guard search and in the days that followed it, Jim’s friends and family assembled satellite imagery, collected wind and current data and arranged for more air and surface searches over the ocean and coast from Oregon and into Mexico. We have walked stretches of coastline and have postered marinas with details on the missing boat. The story has drawn attention from around the world.

Based on our knowledge of the boat and weather conditions, we do not believe that Tenacious could have outsailed our search, whether it was under power, adrift, sailing under autopilot, or even sailing at best possible speed. We have covered an enormous area.

In the last several days, the Friends of Jim group has reviewed all the data with Coast Guard officials. The fact is that we have no evidence as to what has happened to Tenacious or to Jim Gray. Neither we nor the Coast Guard can come up with a surface search plan that is likely to find either Tenacious or Jim, given everything that has been done already.

Accordingly, the Friends of Jim group is suspending its active effort to find Tenacious that has been centered here at the blog. For both the Coast Guard and the Friends of Jim, “suspension” means that the active search has been discontinued due to exhausting all present leads and the lack of new information. Of course, should we or the Coast Guard receive any new information, we will investigate it.

Understandably, Jim’s family is determined to continue to seek answers, but they deserve to be able to pursue them privately. The family deeply appreciates everything the Coast Guard and Friends of Jim have done.

Jim’s wife Donna asked me to add this statement of thanks from her on behalf of the family:

On behalf of our entire family, I would like to thank every individual and organization who helped, and is continuing to help, in a long and difficult search. As the search takes on a new direction, I want you to know that your faith, hard work and boundless creativity sustain us during this unbearable time.

Jim is very lucky to have you as friends and colleagues, and we are very lucky and grateful to have your support.

Below, in the previous post to the blog, we have posted recent photos of Jim, photos of Tenacious at anchor and under sail, and an email address where you can send any information that could help us with our search. Coast Guard and San Francisco Police contact numbers are also listed.

  • The e-mail address is search.jimgray@gmail.com.
  • The Coast Guard contact number is (415) 399-3547.
  • The San Francisco police department contact number is (415) 553-1071.

Thank you, one and all, for this amazing effort to find our Jim.

Contact information and photos

Friday, February 16th, 2007

Anyone with information about Tenacious or Jim Gray should contact:

  • The San Francisco Police Department at (415) 553-1071.
  • The US Coast Guard at (415) 399-3547.
  • Our search email address, search.jimgray@gmail.com.

Jim was last seen on January 28, 2007. Here are several photographs of him and of his 40-foot C&C sailboat, Tenacious, sail number 31869.

Jim Gray

Jim Gray

Tenacious

Tenacious

Finding good examples for multispectral search

Sunday, February 11th, 2007

Folks,

In order to test the multispectral search idea, I was wondering if some of you could help out. In order to have the instrument people figure out if there is even a chance of detecting a boat of the size of Tenacious I am wondering if somebody could help in locating some good examples featuring all the conditions listed below:

- Location of a known boat at a known time and GPS coordinates (sailing races that have been featured on GE or Google Maps, Maud Fontenoy recent trip, others….)
- Said location is within the coverage of either Landsat 5/7 or Envisat ( check http://edcsns17.cr.usgs.gov/EarthExplorer/ , http://miravi.eo.esa.int/en/ <– Internet Explorer only)

- Said Landsat5/7 or Envisat coverage has no cloud on the location of said boat.

As one can see the cloud coverage is pretty important:

http://nuit-blanche.blogspot.com/2007/02/finding-jim-gray-landsat-5-and-7.html

Other possible imagery: Multispectral, Hyperspectral, Astronauts acquired

Friday, February 9th, 2007

Folks,

This is a request for help to the remote sensing community and this is a long shot. I have been talking to some people over the past week about using some lower spatial resolution imagery with higher spectral resolution to see if we could somehow find Jim’s boat. While hyperspectral imagery seems available for a restricted set of conditions (too small of a swath for EO-1), there is multispectral imagery available with resolution between 30 meters to 260 meters.

* 30 meter resolution: In the EROS database of the USGS, there are multispectral views of the scene of interest at about the time that is interesting to our current search. While the resolution is not great (30 m Landsat 7 with ETM+), it seems one can still see boats, I summarized this finding here:
http://nuit-blanche.blogspot.com/2007/02/multispectral-should-be-in-mix.html

I would be expecting some data fusion process to happen eventually between the current set (ER-2, Radarsat, DG/Ikonos,…) and this new set. The other interesting side of this story would be to increase the search area to the whole coast of California.

However, I am not a remote sensing person, hence I do not have access to EROS imagery nor do I have access to processing capabilities at this time. Can somebody in the audience help ?

* The 260 meter resolution can be found on Envisat, a new european satellite:

http://miravi.eo.esa.int/en/

and I found nine shots that could help our effort. The resolution is 260 meters but the resolution (S/N) is pretty high.

Again, does anybody know how to get a hold of this imagery for this effort fast, and can somebody process it ?

Finally, there is another possibility for taking a picture over the pacific ocean with a pixel resolution of about 30 meters per pixel: Astronauts Acquired Photographs taken from the International Space Station.

http://hasp-geocam.blogspot.com/2006/12/orders-of-magnitude-resolution.html

While we can get high resolution shots from Digital Globe, it may be worthwhile to have a much lower resolution but a larger field of view for certain areas especially if there is only one foreign object to detect. I am not quite sure about how to make a request for this type of imagery though.

Friday, February 2nd, 2007

At the bottom of http://www.jonh.net/~jonh/Tenacious/ there are now links to three 31Jan 25m SAR radar imagery files that came to me by way of the MS VE team. Not sure what to do with them, as 25m pixels bigger than a 12m boat. The PNG uploads are in progress and should complete very soon.