My Dad is a retired civil engineer, but still does some jobs on the side. This one involved a fairly tricky septic system install. He needed precise elevations to locate the septic field and generate a topographical map of the property.
On our first trip I just assumed I'd be holding the stick but instead I was operating the transit. Did I mention this was my first time operating a transit? We got some preliminary measurements, but I realized this piece of paper and graphing was just silly. While I'm sure you can buy an expensive surveying program to do this, we don't need this very often, and how hard could it be to write?
First was my browser-based input app. I used this on my iPad to enter the numbers and verify them.
They're plotted on a neat map but it's all done in client-side Javascript because the site had awful Internet data coverage. It's actually generating a SVG vector drawing on the fly using jquery.svg, so I can export a high quality printable graphic perfectly to scale.
That was pretty cool, but it was still necessary to interpolate the points to generate a topographical map. I figured out a suitable algorithm involving way more trigonometry that I've used since high school, but generated 3 times the number of data points in interpolation:
And then plotted the points out on the graph:
Very cool! There was also a second diversion where I server-based solution where you could upload the measured data points and get back an Excel spreadsheet. Who knew that in an hour you could be exporting fully formatted xls Excel spreadsheets with all of the columns sizes and formats not just comma separated values! That used Apache POI, a Java library for manipulating Microsoft Office documents. Cool stuff!
On our first trip I just assumed I'd be holding the stick but instead I was operating the transit. Did I mention this was my first time operating a transit? We got some preliminary measurements, but I realized this piece of paper and graphing was just silly. While I'm sure you can buy an expensive surveying program to do this, we don't need this very often, and how hard could it be to write?
First was my browser-based input app. I used this on my iPad to enter the numbers and verify them.
They're plotted on a neat map but it's all done in client-side Javascript because the site had awful Internet data coverage. It's actually generating a SVG vector drawing on the fly using jquery.svg, so I can export a high quality printable graphic perfectly to scale.
That was pretty cool, but it was still necessary to interpolate the points to generate a topographical map. I figured out a suitable algorithm involving way more trigonometry that I've used since high school, but generated 3 times the number of data points in interpolation:
And then plotted the points out on the graph:
Very cool! There was also a second diversion where I server-based solution where you could upload the measured data points and get back an Excel spreadsheet. Who knew that in an hour you could be exporting fully formatted xls Excel spreadsheets with all of the columns sizes and formats not just comma separated values! That used Apache POI, a Java library for manipulating Microsoft Office documents. Cool stuff!
