I was asked create a little google map showing the location of Polar bears. I've been given the location data in lat-long format.

For each bear I've been given a file containing the following headings:

Date Time Year Julianday Hour Minute Activity Temperature Latitude Longitude

The intention was to show the migration of these bears over time - so I'd take the date, take the time, take the lat / long and animate a google map (straight ahead javascript + googlemaps api stuff - got it working... easy).

However, I've now been asked to show the movement of arctic ice as well as bears.... Google maps doesn't have a North Pole... and while I've managed to overlay some ice, it just looks like a big white blob which didn't render out properly due to the lack of North Pole.

I've been asked to use data found here http://nsidc.org/data/masie/.

I need to find a way to take the nsidc data, and take the polar bear data and combine them to form a series of png files.

Once I have the png files I can animate them.... vistor hits 'play' and all the files play back to show the bears and ice moving over time. The play stuff is easy... I just don't know how I am to create these files...

To compound things, I've also been asked to include shipping data (also supplied in lat lon format)

Normally I'd do lots and lots of reading to try and figure stuff out- however, I've been given 3 days to do this... I've tried a few things...downloaded "QGis" and pulling in the data - but nothing appears. I don't have a clue.

How do I / where do I begin?

Sorry - this is the worst, most vague question ever....


1 Answer 1


Perhaps this idea can help you out here, using GMT (http://gmt.soest.hawaii.edu/) you can read the nsidc binaries based on this and then plot them nicely as PNG (with ps2raster it's possible also to have transparent PNGs) in the projection you want. With GMT you can also animate the images you want like here.

Hope this helps,

  • Thanks. I can't get Fink to run on my mac (needed for GMT) - so I'm off to a friends house to see if we can get this working. I'm guessing once I have the png's - I can overlay the bears as transparent pngs also?
    – Rob
    Commented May 31, 2013 at 13:02
  • you're welcome, you can use also the bzip2 installers for linux (I think), but not sure because I don't have a mac. Afaik with fink everything should go smooth. Well yeah, I think you meant the bears activity (tracks?), if so sure, just make your basemap with coast (psbasemap or just pscoast), overlay everything you want on it (normally with psxy) and then convert the output postscript file to png (ps2raster -Tg or -TG for transparent). Making only the track alone, you'd need only psxy and then ps2raster, but then you'd need to work a bit the map framework.
    – Gery
    Commented May 31, 2013 at 13:52
  • Hi Gery, I've been wrestling with this - and really struggling. Do you take on contract work, and if so, can I pay you to do it? Sorry - just completely clueless... can't figure it out.
    – Rob
    Commented Jun 4, 2013 at 16:48

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