Developing GIS products for older historical periods can be tricky. The further back in time you go, the less comprehensive the map coverage, the less accurate the surveying, and the more obscure the projections. In a project with Kristen Harkness and others, we are recovering and mapping events during an insurgency that took place 60 [...]
Land cover (land use) estimates assign points or regions on the earth’s surface to classes like forested, farmland, urban development, etc. There are hundreds of land cover data sets and methods covering different regions, time periods, and special topics. In a paper under review, my coauthors and I test methods of estimating population density at [...]
For machine vision projects, I often need a quick and easy way to label images as training data. After a long false start with exporting images as cells in an excel file, I found a rather elegant online solution using dropbox to host image segments and google spreadsheets for labeling by myself or research assistants.
A remarkable amount of data are hiding in historical records in hand written forms, electronic printouts, or typed tables. This post describes methods I use for three types of difficult documents consistently structured forms, inconsistently structured forms, and near machine readable tables.
As I’ve written on here before, digitizing political maps is no easy task. One tough problem is digitizing background colors which identify things like land cover. Consider this section from a Vietnam War era military map of South Vietnam. There are three background regions, a dark green for forested area, a slightly lighter green for [...]