Support the Arctic Sea Ice Forum and Blog

Author Topic: Sea ice calculations and instruments used.  (Read 2577 times)

LRC1962

  • Frazil ice
  • Posts: 431
    • View Profile
  • Liked: 5
  • Likes Given: 1
Sea ice calculations and instruments used.
« on: March 23, 2015, 05:05:37 PM »
We show a variety of charts from a variety of sources to calculate sea ice extent and area. Each have their own mathematical models and use different source satellites. The question I have is has anyone thought of doing something similar to calculate sea ice as they do in astronomy or surveillance?
In astronomy there are two different ways of getting higher definition. One way is making bigger and more powerful telescopes, the other is to have many telescopes take the same picture and combine them.
You can do the same thing in photography. take a picture with a bigger heavier camera, or as what is being done with some new advanced surveillance UAVs load it with a lot of cell phone cameras and actually get even better results.
Back to sea ice has anyone thought of taking the data from all those satellites flying over the poles combining them and coming up with a higher resolution end product? Or is it a case that each satellite is proprietary and no one wants to share raw data, or the computer power needed to combine all that data is technologically not yet feasible? An argument could be made that they are looking at different types of data that are not really compatible, but would it not be that much dissimilar to taking the same picture but with different filters then combining them to get one picture? Or is that too simplistic an illustration?
"All truth passes through three stages: First, it is ridiculed; Second,  it is violently opposed; and Third, it is accepted as self-evident."
       - Arthur Schopenhauer

Peter Ellis

  • Grease ice
  • Posts: 617
    • View Profile
  • Liked: 35
  • Likes Given: 11
Re: Sea ice calculations and instruments used.
« Reply #1 on: March 23, 2015, 06:03:38 PM »
Too simplistic.  It would be like trying to combine a radio telescope, the Hubble space telescope and the massed TV aerials of Western Europe >.<

We already can and do combine observations from different sensors in a way - it's what we do when we look at the ASCAT radar images and match them up against the passive microwave imagery and/or the MODIS visual wavelength imagery.  But it's a very limited thing because they show such different data.

Also, the other key thing that lets interferometry work to get better resolution is making simultaneous observations. Merging a microwave image taken by satellite A with another image taken by satellite B 4 hours later won't be nearly as effective!

viddaloo

  • Nilas ice
  • Posts: 1302
  • Hardanger Sometimes
    • View Profile
  • Liked: 1
  • Likes Given: 0
Re: Sea ice calculations and instruments used.
« Reply #2 on: March 23, 2015, 06:21:32 PM »
We show a variety of charts from a variety of sources to calculate sea ice extent and area. Each have their own mathematical models and use different source satellites. The question I have is has anyone thought of doing something similar to calculate sea ice as they do in astronomy or surveillance?

Excellent idea, LRC. I'm hoping to see something like this done for SIV.
[]

epiphyte

  • Frazil ice
  • Posts: 383
    • View Profile
  • Liked: 22
  • Likes Given: 17
Re: Sea ice calculations and instruments used.
« Reply #3 on: March 23, 2015, 06:58:10 PM »
I've been playing with a slightly different idea - which is to try to systematically correct for ice movement backwards over time from the current date, then incorporate knowledge from previous looks, using the same source, at the same ice that now occupies each pixel. I'm hoping that it might yield a picture that has more information content than a single look from a single angle, with a single surface scatter/cloud pattern, etc.

Even working from low granularity data over a small area there's a large amount of processing involved - I've been trying to compute the day-to-day transformation + remapping using an FPGA + modified machine-vision logic - but so far all I've got from it is a flashing LED and a headache. Will let people know if it ever comes to anything...