Digital Geography

Some ways to produce high-res DEMs – tools and data

Many of us use digital elevation models (DEMs) for a whole bunch of different applications. There are some standard products which everyone should know, like SRTM1, SRTM3, ASTER, GLOBE or ETOPO1 for the land surface or GEBCO for bathymetry. However, they have a relatively low resolution and are therefore not suitable for all purposes. During the last few years there has been a huge progress in producing much better DEMs, especially local ones, using a wide range of techniques like LiDAR, photogrammetry, image correlation, structure-from-motion (SFM) etc. Some of these techniques make use of powerful, but expensive equipment (e.g., LiDAR),…

A Drone for the Holidays

So, by now some of you have opened a holiday gift and it turned out to be a drone.  I was fortunate enough this year to get a 3DR IRIS+ in my stocking.  After a few flights I wanted to put together a quick note comparing this with another popular consumer drone, the DJI Phantom 2 Vision+ (P2V+).  I have a P2V+ that I use at work and put quite a bit of thought into what I would get for personal use.  Hopefully this will be of use to readers who may be considering the purchase of a drone this year.  Allow me to…