Archive for the ‘Other data sources’ 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
  • 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,

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



Finding good examples for multispectral search

Sunday, February 11th, 2007


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 , <– 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:

Other possible imagery: Multispectral, Hyperspectral, Astronauts acquired

Friday, February 9th, 2007


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:

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:

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.

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.

Beat the bushes for video?

Sunday, February 4th, 2007

Krista Bradford brings up an intriguing idea. Anybody want to take charge of pursuing this? Maybe something to coordinate with SFPD…

In a prior life, I worked as an investigative journalist for some 20 yrs. And in that capacity, I learned it was often VERY helpful to check for videotape that may have captured an event I was covering. (I helped get a wrongfully convicted youth out of prison because we found such a tape that proved he wasn’t where prosecutors said he was . . .)

As I consider the massive review that is being done of satellite images, I wonder whether there has been a thorough check of any and all video cameras/surveillance cameras/web cameras pointed in the direction of the bay, through whose view Jim’s boat may have passed.

Has anyone checked to see what video is available? It might tell us whether Jim’s boat made it out of the SF Bay, for instance and give us a better sense of where it was headed.

Places to check:
The local assignment desks of all of the area television stations. Ask them if they have any cameras pointed at the bay or are aware of any services that may have same, such as traffic cams or weather cams. Additionally, I would imagine there might be extensive security surveillance cameras stationed about the bay. Other places to check would be “stringer services” . . .freelance videographers and production houses. They may be aware who might have cameras pointed at the bay . .

And she followed up with some specifics:

To start, I’d check with the following:

NEWS VIDEO ( See wikipedia entry on TV stations in SF Bay )
Calling into the stations, I’d ask for the assignment desks (they deal with acquiring video 24.7) and for the reporters covering the story, as they may be more motivated to help. I would ask them if their stations have cameras that continually record pointed at the bay or whether they subscribe to traffic cam or weather cam services that are pointed at the bay. I would ask if they could provide you with the names of all stringer services (freelance videographers) and brainstorm with them. Was anyone up in a chopper or plane filming or taping that day?

SURVEILLANCE VIDEO. Talk to cops (the reporters from above might help) from the precincts along the bay, from headquarters, and at the bridges. Also check other police orgs such as homeland security. I suspect people in our computer community might have friends in police intelligence who could help, if we could get the word out. Also, if searchers checked the shoreline adjacent to Gray’s probable course, you could spot surveillance cameras and inquire about them to track down the video they may have captured.

Was anyone up in a chopper or plane filming or taping that day? Was anyone shooting alongside the bay?

Are there any pointed at the bay?

A long shot, but people use their cell phones to shoot video now all the time. Was anyone shooting toward the bay on that day?

Visualization of Coast Guard buoy data

Sunday, February 4th, 2007

I think the community will be interested in this map of the buoy data provided by the US Coast Guard. The USCG dropped the buoy at 12:00Z on Monday, 1/29. The data run through 16:30Z on Friday, 2/2. The buoy was dropped between the Farallon Islands and the Golden Gate.


Dawn Ortiz
Center for Space Research
University of Texas at Austin

track of buoy dropped by US Coast Guard

Webcams on SF Bay, including GG

Saturday, February 3rd, 2007

Just found this site which has links to a various web cams, including web cams apparently pointing at the Golden Gate Bridge.  A number of the sites seem to be dead.

-Jim Bellingham

Ship tracks in SF Vicinity

Saturday, February 3rd, 2007

There is a system called AIS that is used for tracking large ships.  Most smaller boats (e.g. like Jim’s, or like a fishing boat) do not participate.  However if the was a collision with a large vessel, the large vessel track should be in the archives.  Maybe it might even show a ship slowing or turning at an odd point.  There is real-time data on the web:

A few days ago we did some checking on this (circulated by email to some of you).  Key points include:

– The San Francisco Marine Exchange is not maintaining archives. 

– The BoatingSF said they are maintaining an archive right now (part of a Santa Clara U research project), although their receivers do not go beyond where Jim’s boat was last heard from. 

– The Coast Guard does maintain an archive, and routinely uses the archive for investigations like this — but getting data from the archive is difficult.  Maybe the folks who have been interacting with the CG can get access and post it.

-Jim Bellingham

Take Pictures Too

Friday, February 2nd, 2007

It’s good for folks to get up in planes and try to spot Jim, his boat, or other clues. And it’s good to have satellite data. I suggest we combine the ideas and try to have a second spotter in the planes who is taking (hi-res) pictures so that eyes at home can comb through them looking for things that might not be evident from a moving platform. The pictures can be posted somewhere for volunteers to examine. When the pictures are of coastline or slightly inland, it’s probably ok for the spotter to merely note rough position. If something is spotted, I’m sure we can figure out where it is by comparing to clear satellite images.