Digital Geography

Geotagging Basics with ExifTool

  Why Geotagging? In a recent post, I discussed the new drone that I got for the holidays and a bit about how I was using it for developing map products.  I do this using structure from motion algorithms and when working with a lot of images it is a great help if there is a good initial estimate of the image location.  This is where geotagging comes in. If you have a smartphone, then you are familiar with geotagging.  Most iPhone and Android devices tag their images when they are collected.  That is great if you are uploading to Facebook or Pinterest,…

Freeware SAR processing (Part 1.)

One thing about working with synethic aperture radar (SAR) data is that regular image processing functions are often unsuitable. This is because most processes were design to deal with issues related to passive multispectral data in the visible-thermal infrared wavelength range. SAR imagery is derived from an active sensor which introduces particular problems or rather requires special solutions. The wavelength range is also very different meaning that the interaction between the energy and target is dissimilar to that of visible-infrared radiation. Hence we need a different set of tools to work with SAR data. If you have the money there…