I just got this from one of my co-workers ... posting it for her as it's more time critical than normal :

My friend Ralph is leading a search and rescue effort for a ship that's been missing on the Tasman Sea. They were last heard from June 4. We're trying to get images from May 28 to the present (emphasis on the earlier part of that window) to see if we can get any clue of what's happened to them. There are 7 people on board - one of the people on the Schooner SV Niña is Evi Nemeth, author of many famous Unix/Linux sysadmin manuals. : (

Google granted us a free license to Google Earth Pro, but it still doesn't have images that are recent enough. I wrote Google to see if they could give us more recent images, but I haven't heard back. I'm kind of lost when it comes to Earth-pointed data, but then I realized I have a friend who is involved in Informatics for the American Geophysical Union. : )

Any idea how to get high-res data? The ship is 70 feet long, so the 1.5-m resolution stuff in google earth would be fine. Until we get images, they're focusing on ocean current models + drift models for other abandoned ships to help the aerial searchers more clearly refine the expected location for the ship.

The ship was fairly well equipped for a 3-week cruise, so it's possible for them to survive with their supplies + fishing for several months.

Any advice is appreciated. We're posting info on the efforts at:


Anyhow, if you have any idea how to get high-resolution data over the Tasman Sea, I'd be very happy to hear it.

1 Answer 1


WMO OSCAR has a (complete?¹) list of current space-borne high resolution optical imagers, defined as instruments with a "spatial resolution in the range of less than 1 m to a few 10 m.". Scroll down to "Current instruments". I'm not an expert in high-resolution optical imagers, but I suspect the problems are as follows:

  • The higher the resolution, the smaller the field of view. At high resolutions, it either takes a very long time to cover the entire globe, or data are only acquired on pre-order and for-pay. Also, it's not free. Some examples:

    • GeoEye has a resolution of 0.41 metre, and covers the globe in 6 months. Otherwise, data are available for pre-order for a specific location, but the field of view is too small so it likely won't help you. Competing WorldView has similar properties.

    • AWFS has global coverage in 5 days, but the resolution of 56 metre is insufficient.

    • CMT has a resolution of 4 metre, and global coverage in 104 days.

    • ETM+ on LandSat has a resolution of 15 metre, and global coverage in 16 days.

    • HiRi on Pleiades has a resolution of 0.7 metre, and global coverage in 26 days. I don't know if they actually acquire information accordingly, or if this is just a theoretical limitation: it would be an awful lot of data.

    If you browse through the list I linked above, you will find many more examples.

  • Data may be difficult or impossible to obtain, and most data are not free and open. In fact, many high-resolution optical imagers are carried on spy satellites. Good luck.

I don't know practically speaking how to get the data. Many instruments are commercially operated. You might be able to get more information by contacting companies such as GeoEye, RapidEye, or DigitalGlobe. Perhaps your best bet may be to see if any agency can get recent Pleiades data. If WMO OSCAR is correct, it might just be good enough: 0.7 metre and 26 days appears to be the best thing out there. Again, data are not free and open, but search and rescue organisations in most countries should have access to the necessary funds.

¹It seems not to include spy satellites, but those might not have open data available...

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