EarthEnv-DEM90

Tuesday, 30 August, 2016

It’s been a little while since my last global DEM news update but (somewhat belatedly) I came across Earth-Env DEM90 which merges SRTM (shuttle radar) and GDEM (ASTER photogrammetric) global DEMs. And more specifically the CGIAR-CSI SRTM DEM which is gap filled and hydrologically correct.

Neither DEM is actually completely global missing, to greater or lesser extents, the polar regions. GDEM has greater coverage (owing to the overpass of the satellite) but is generally considered to be less accurate than SRTM. So its inevitable that a merged product should arrive which covers ~91% of the globe and mitigates much of the noise and void problems of the individual products. Full methodology can be read here.

The Success of Failure

Wednesday, 24 August, 2016

I’ve blogged before about the success of failure and how critical it is to improving in whatever domain you are working in. In my review of Matthew Syed’s Bounce I noted the central importance of purposeful practice. That is, practicing at the “edge” which inevitably leads to failure. Without failure you don’t know where (and how) to improve. Failure is vital to success.

Donald Clark provides a nice succinct list to the 5 levels of failure. Read it - it’s good. So, in abbreviated form:

1. Failure is normal in life, it happens, recognise it for what it is.

2. Break it down (or the science of marginal gains). Break your task down in to small steps or elements, strip it back, analyse it and improve. For those in the teaching game, Lesson Study looks at these building blocks in the classroom.

3. Practice, then practice some more! Do it, fail, feedback, improve, stretch your abilities.

4. Catastrophic Failure: practice those tasks that lead to major failure… so that they are unlikely to happen when it’s the real deal!

5. Reboot: learn, try, fail, go back to the beginning of the level and try again. Its a gaming strategy and incredibly frustrating, additive and the way to accelerated learning!!

So, go ahead, fail and go do it again.

Anyone have any good (big or small) failure stories?

word word count

Wednesday, 17 August, 2016

Yup, that’s right… how do you do a word count in Word? Well, the simple answer is Alt-T, W and particularly for the ribbon-challenged like me who prefer the keyboard. But what happens if you are working to a specific word count, have ancillary information in the file but only want the content word count? Well, that’s a little more tricky and requires some lateral thinking (or some DuckDuckGoing).

And the (or one) solution is to put your ancillary information in a different style, change the font attributes to include “hidden” for that style, but then in the Word options make sure “print hidden text is selected”. That way you can see it and print it - crucially though Word excludes hidden text from word counts.

Read in full here

Google Earth Updates

Friday, 12 August, 2016

A little late in getting this out, but Google announced late-June updates to imagery in Google Earth. This is significant for a several reasons (and their post is worth reading):

1. Landsat 8: the base imagery they Google fall back to if no high res aerial imagery is available is now Landsat 8. Previously it was Landsat 7. Google need moderately up-to-date imagery but the Landsat 7 partial failure meant a slower process for acquiring global imagery. With enough global data in the back pocket, they can now switch to the newer sensor.

2. Google Earth Engine: Google’s cloud based image processing service is used to process the imagery. This leverages huge online image archives and processing power to allow very fast MASSIVE processing. So, in this case, for *every* pixel across the whole planet, using every available Landsat 8 image, select the one with the lowest cloud cover. Very neat way to create a global cloud free image. Or to put it in their marketing speak:

Like our previous mosaic, we mined data from nearly a petabyte of Landsat imagery-that’s more than 700 trillion individual pixels-to choose the best cloud-free pixels. To put that in perspective, 700 trillion pixels is 7,000 times more pixels than the estimated number of stars in the Milky Way Galaxy, or 70 times more pixels than the estimated number of galaxies in the Universe.

3. The Verge: just to show how mainstream this is, even The Verge picked up on it. Remote sensing is joe bloggs interesting now!