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Sailor_Hutch · 16-07-2013, 10:53

Please excuse my ignorance about this subject (satelite imaging). Is the problem centered around the idea that oceans are scanned at a much lower resolution? I guess that's whats being said, because I can easily see my little compact car in my driveway via google earth.

Naamah · 16-07-2013, 11:33

Quote:

Originally Posted by Sailor_Hutch

Please excuse my ignorance about this subject (satelite imaging). Is the problem centered around the idea that oceans are scanned at a much lower resolution? I guess that's whats being said, because I can easily see my little compact car in my driveway via google earth.

Yes that's exactly it. Satellites don't do detailed images over open ocean as there is little out there of interest generally...under situations like this detail and regular updates would be beneficial but logistically improbable under normal conditions which is a shame

Friend of Nina · 16-07-2013, 13:39

Quote:

Originally Posted by Sailor_Hutch

Please excuse my ignorance about this subject (satelite imaging). Is the problem centered around the idea that oceans are scanned at a much lower resolution? I guess that's whats being said, because I can easily see my little compact car in my driveway via google earth.

Hutch I don't know!!
That's interesting about google earth but wonder if satellite coverage not as good over the sea???

Cherie

**boatman61** · 16-07-2013, 13:46

Quote:

Originally Posted by Friend of Nina

Hutch I don't know!!
That's interesting about google earth but wonder if satellite coverage not as good over the sea???

Cherie

Now your assuming satellites actually cover that area 24/7...
Why should they.. there's no threat to the US down there... also most GE images are 2 or more years old.

Naamah · 16-07-2013, 13:48

Quote:

Originally Posted by Friend of Nina

Hutch I don't know!!
That's interesting about google earth but wonder if satellite coverage not as good over the sea???

Cherie

Sadly it isn't as per my previous post. However these images Cherie has obtained might be better.
I'm only a naval officer so sadly its a little out of my expertise all the techy stuff. I'm hoping 70ft will show up nicely on the resolution obtained

Naamah · 16-07-2013, 13:53

As per what I've previously said. ..
The images obtained by cherie are recent and proven dated recent.
They will be of more use than google earth which are not current as it is not logistically possible for satellites to monitor open ocean with little or no interest on any regular basis.

Maybe I should have posted more than I have but I would like to be involved in reviewing images if my help would be apprecaited.

opusnz · 16-07-2013, 14:28

I haven't tried it yet but there is info on a free Geotiff viewer here:

New Free Stand-Alone MRSID Imagery Viewer/Exporter From LizardTech

http://www.lizardtech.com/downloads/category/#viewers

I hate to say it but I think 22m per pixel is going to be a problem. I tried to see an oil rig on a similar resolution sat photo once and it was almost impossible to see, even though it was in a fixed spot with a known latitude and longitude and I could zoom right in to it. It just showed as a slight blurring of color in the photo.

I really wish I could be more constructive.....

ShaktiGurl · 16-07-2013, 15:54

Quote:

Originally Posted by barnakiel

Perhaps the source image can be split, so that it gives tiles sized so that a less than commercial grade machine can be used to view them. Remember pcx.

Is 22m per pixel enough to find a sailboat?

b.

A 22m pixel is over 70ft^2. A boat the size of Nina (60-70ft) would not be indentifiable with this imagery. The pixel may be slightly brighter than surrounding pixels but no real shape could be seen. To give reference, Google Earth images where you can see boats in a marina have a spatial resolution of 2-4m^2 and even then it can be hard to tell. We really need images with resolution of 10m or less to try target detection or visual identification.

Additionally, the images have a high percentage of cloud cover making ID more difficult.

I would be happy to provide what I have if there is a place to upload but it is my opinion that these images are not adequate for what is needed.

ShaktiGurl · 16-07-2013, 15:57

Quote:

Originally Posted by Sailor_Hutch

Please excuse my ignorance about this subject (satelite imaging). Is the problem centered around the idea that oceans are scanned at a much lower resolution? I guess that's whats being said, because I can easily see my little compact car in my driveway via google earth.

Yes, for the most part. Companies that provide high resolution images generally look at land. There just is no real commercial business for acquiring images over ocean and the data storage requirements are huge. You can purchase images tasked to look virtually anywhere you like, but it can be quite expensive. Then you need to know what to do with them, adding to the expense.

ryon · 16-07-2013, 16:23

Do we have any contacts in the military? The Tasman Sea is fairly high, or low depending on your perspective, from the Equator. Polar satellites, which are mostly military, could be useful in this area.

Also, we might be searching for a bow wake, at least in earlier images. Or for debris, however you detect that.

Pelorus32 · 16-07-2013, 17:17

I had said that I would seek an FTP site, however after discussion with Cherie off-line I'd parked that awaiting events.

I've taken action this morning to see if I can secure something temporary and I'll report back when I hear.

Pelorus32 · 17-07-2013, 02:25

OK I have secured free FTP. I need to know data storage requirements - let's not underestimate - and any other requirements. ShaktiGurl can you help there.

Cherie, the guys offering this will also blog about this to their community if we want. It's a large international tech community and they'd love to help in any way they can. Is there anything we need?

Regards
Mike