Friday, 29 April 2011

Hydrographic Charting

A few things have cropped up in my inbox recently about charting.

The first one was about the perceived accuracy of electronic charts and the IHO survey which is running. Now accuracy of charts - or, more correctly, the accuracy of the source data - has been one of my career mantras. Metadata is oh, so, unsexy but so, so critical and often gets overlooked. Just because a chart is digital doesn't mean it's any better than a paper version. Indeed, just because a chart is metric doesn't necessarily mean it has any/much more data than the fathoms version. It's all down to fitness for purpose and the user knowing what they have. I've had many conversions with Mariners who have said (after they hit charted feature) "but I didn't know the paper chart wasn't on WGS84 Datum!" "Did you read the chart notes?" I'd enquire? "What chart notes?" was the response. Give me a brick wall and I'll bang my head against it.

The second one was a new book, The Electronic Chart which is now on its 3rd edition. ENC and ECDIS display issues are becoming quite a hot potato and I wonder how much this book covers it. Perhaps I should buy one and read it!

I'm also realising I'm not such a geek as I thought. Or perhaps I just hang out with geeks. On a recent car journey with an RN hydro surveyor he admitted that when shore-side the first person to spot a trig/benchmark had to be bought a beer. So it's not just me that goes around looking at pavements and walls then...

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