Cartography Links

Monday, 31 October, 2016

This week a selection (well list!) of two relatively recent resources which struck a chord.

1. cartographic-design: this is hosted over at Github and is a series of links to cartography sources that supported Maptime Boston’s May 2016 meetup. Its a relatively short but extremely useful set of resources for this wanting slightly more detail on a range of carto/design topics. One to refer back to - often.

2. Beyond the Core Knowledge: a blog post from Gretchen Peterson that looks at some important topics that sit outside (for example) The GIS&T Body of Knowledge. It’s interesting because it takes a concept, a dataset and the hoops to jump through to get (more or less) through to the end. And it’s nice because she covers all those inner decisions you end up making as a designer to get to the final product.

Open Access WeeK: article at T&F

Wednesday, 26 October, 2016

Its Open Access Week this week and our publisher at the Journal of Maps, Taylor and Francis, are running a range of activities promoting OA. So go check out the resources to look at what OA has to offer and, not least (!), my own article on implications and stakeholders in moving to OA.

Data transfer and memory cards

Monday, 17 October, 2016

James and I were in Norfolk a few weekends back completing data collection for his PhD studies (his blog has at least one post relating to this) and the whole topic of data transfer speeds came back to haunt me. Amongst a number of cameras, we had been shooting with the Nikon D700 using a Sandisk 16Gb Ultra card which has read speeds of 30MB/s. We actually filled the card on day 1 (1000 shots) and need to unload the data off it. I had brought with me my cheap and cheerful Integral CF->USB card reader which works fine. Except it took the best part of 30 minutes to copy the data off the card around <5MB/s. Painfully slow.

When we got back I thought I’d dig back into data transfer speeds again. Remember that the firmware (and hardware) in a digital camera will be able to use cards up to a certain specification. The D700 is at least 64Gb cards up to 90MBs (although it might not be able to utilise the full speed of the card). My Fuji XM1 can take 32Gb cards at 50MBs. Now to achieve these speeds during data transfer to a PC, all parts of the chain need to be quick - card, card reader, USB port, bus and hard disk. In this instance the card reader was the limiting factor as it was plugged into a USB3 port on a new laptop. And just as a reminder, USB3 has a throughout of (depending upon what you read), somewhere above 400MBs (and doubling for USB3.1), whilst USB2 somewhere around 35MBs.

So, one lowcost USB3 card reader later and a new (lowcost!) 50MBs SD card, plugged directly into the USB3 port and read speeds race along. Getting this kind of throughout is both cheap and easy, but its not hard to accidentally put a weak link in that chain and see those rates plummet.

FREE EPRINT: Selecting cameras for UAV surveys, GIM International

Thursday, 13 October, 2016

James O’Connor and Mike J. Smith (2016)
GIM International

With the boom in the use of consumer-grade cameras on unmanned aerial vehicles (UAVs) for surveying and photogrammetric applications, this article seeks to review a range of different cameras and their critical attributes. Firstly, it establishes the most important considerations when selecting a camera for surveying. Secondly, the authors make a number of recommendations at various price points.