Are G.I.S. and Surveying and Engineering moving closer together? Should they move closer together? If you follow the old joke about what G.I.S. stands for you may not think so. If you look at what G.I.S. actually stands for and what it is capable of you might ask yourself why we have not been taking advantage of this more than we have.
Geographic Information System. Surveying is Geographic so that is good right? Information is good right?. A system is good right? So why then such the push back from combining GIS and Surveying? For so long GIS has been used as a general representational location as opposed to an exact location and I think that has been the big hold up. Surveyors are trained that close enough is not good enough (except in the old adage of close enough for government work, but that is a topic on my other blog).
One of the things I think has kept this natural merging is the lack of ability to easily combine the data source and the data. Meaning there have been few methods over the last few years to move data from our survey platforms to GIS platforms. Or perhaps they have been there and we just didn’t know about them or how to take advantage of them.
We were given dxf as a means for moving CAD drawings from one program to another, and xml to move data from one package to another, but what about GIS data? Enter the SHP file. The problem is, many of us know so little about the SHP file.
Shapefiles store primitive geometrical data of points, lines, and polygons in coordinate formats of x and y (or most often latitude and longitude). These primitives are of limited use without any attributes to specify what they represent. Therefore, a table of records will store properties/attributes for each primitive shape in the shapefile. Shapes (points/lines/polygons) together with data attributes can create infinitely many representations about geographical data.
While the term “shapefile” is quite common, a “shapefile” is actually a set of several files. Three individual files are mandatory to store the core data that comprises a shapefile: “.shp”, “.shx”, “.dbf”, and other extensions on a common prefix name (e.g., “lakes.*”). The actual shapefile relates specifically to files with the “.shp” extension, but alone is incomplete for distribution, as the other supporting files are required.
The mandatory files include the .shp, the .shx, and the .dbf. The optional files are the .prj, .sbn and .sbx, .fbn and .fbx , .ain and .aih, .ixs, .mxs, .atx, .shp.xml, and .cpg.
Now that we know the details of the files how do we get them in and out of our Surveying programs and in to G.I.S. applications? Watch the short video below on how to export a SHP file out of Carlson Survey.