Gathering and Digitizing Geographic Data
In This Chapter
Using the best data for your GIS
Incorporating data from GPS, remote sensing, field collection, and censuses
Adding existing maps to your GIS
No GIS can operate without substantial amounts of quality geographic data, no matter how you intend to use it. You can purchase these data from commercial vendors, but the surest way to guarantee your GIS database integrity is to build it yourself or carefully supervise its construction for the specific task or tasks that you have in mind. You know exactly what you want your GIS to do and how you want it to help with your decision-making.
Because GIS offers so many possible applications, many possible types of data exist that you can put into the GIS. This chapter discusses a few examples in four basic data groups that you’re most likely to encounter — GPS, remote sensing, field data, and census data. In this chapter, I also show you how to work with existing maps and prepare them to be digitized.
Identifying Quality Data
The sources of GIS data, as well as their accuracies, sampling methods, and many other factors, affect not just the quality of a GIS database, but also how effectively it serves your decision-making needs. I’ve personally tried to build GIS databases based on over 10,000 observations of wild animals. Unfortunately, because the study was based on behavior, rather than movement through the study area, the researchers took the vast majority of the samples ...