-
We were pioneers of the new age
I had a conversation the other day with a young fellow that was out surveying by himself with his RTK equipment. Saw him setting up his base and fiddling with the rover and then proceed to waltz around a site setting lath for what appeared to be grading stakes. Seeing how I own motor vehicles and blue jeans older than him, I thought I’d see if he spoke English.
He was actually a fairly bright young man. Went to work for a surveying outfit when his CE career was put on hold by life in the form of a pregnant girlfriend. He seemed positive and after a few key questions to size up his abilities, I decided he probably was helping the cause and not hindering. The conversation mutated to surveying equipment. He referred to TS work as “old school” and admitted with canopy and certain conditions he relied upon his robot. I was satisfied he understood what he was up against.
The conversation drifted to “back in the day” and he was curious about the older equipment. He had seen an old top-mounted EDM in a closet and was marveling at its shortcomings with only measuring a sloped distance and having to rely upon an operator calculated horizontal distance. I guess that kind of thing might seem weird to younger folks. After a few stories he made the observation that back in the late ’70s and early ’80s we were the “pioneers of the electronic age of surveying”. I just agreed with a “I guess so”. I left him to his tasks. Afterwards I started reminiscing about those days and some of the hurdles with which us “pioneers” had to contend. I remember one hurdle in particular was convincing our superiors the electronic equipment was capable of carrying and providing predictable vertical positioning as well as horizontal.
Now keep in mind, for those fortunate enough to have not lived through it, the old school ‘chain-and-transit’ camp (our bosses and employers) was a very skeptical bunch of folks. I even had a party chief that would make us drop a chain from time to time and “check” the distance displayed on electronic equipment. It was something that might not deserve trust…
After a few years of traverse closures in the 1:60000 range instead of 1:5000 some of the old guys were taking notice. I worked for one “progressive” company that actually allowed us to set the final centerline street control in new subdivisions with the EDM. Setting all the property pins was still, of course, left up to the standard chain and transit to avoid any costly mistakes.
And then Hewlett Packard came out with the 3810A; something they called a “total station”. Its greatest feature was a theodolite style circle and an automatic reduction to horizontal distance feature that kept things simple. The day of the ‘radial stakeout’ and working from ‘control points’ had dawned. Now remember if your boss was ok with you shooting some topo in a radial fashion and reducing the points to a coordinate base, we still provided good vertical data with spirit leveling. I can remember jobs with 2 instruments set up; a total station AND a standard level. Two rodmen walked about locating features; one with a reflector rod and the other with a level rod. In a field book we recorded an azimuth angle and horizontal distance from some backsight and then kept running level notes on the opposite page. It kept a crew busy to say the least. And “reducing” the notes to any sort of COGO coordinate base was time consuming. We didn’t even have HP41s at the time.
Now as the ‘old school’ bosses were starting to feel comfortable with distance measure WITHOUT a chain (tape), they still dismissed the equipment’s ability to measure vertical distances as “not accurate”…so we continued to rely heavily upon electronically derived horizontal measurements and the whole time still breaking out the level and rod to determine vertical distances. But there was a knob on the front of the HP that looked like this:
For those unfamiliar with the equipment it is a gang switch that varied the LED displayed distance as slope, horizontal, vertical and zenith angle. That knob fascinated me. Now my boss is trusting this high-dollar rig to provide an internally calculated horizontal distance (all it actually measures is a slope distance) and then wants to tell me it can’t determine vertical distances with any accuracy. Bullcrap. If the calculated horizontal distance was accurate, the vertical must be also.
I don’t remember what job it was but I had the perfect opportunity to test it out. We had several control points that also had good spirit levels ran between them. With the help of drawing a little picture in the field book to keep track of rod height and instrument height, I shot all these control points and determined an observed elevation for them. Comparing them to the level notes revealed a fascinating accuracy. Although missing the record elevation by a few hundredths here and there..it was good elevations.
Of course my argument fell on skeptical ears. Just lucky shots. And my HI was determined with the laughable technique of holding the level rod on the control point and visually reading the rod at the trunion point of the instrument…I mean how sloppy can you be??! ….But us ‘kids’ in the field knew we were right. And we could prove it. The first time I actually used the technique was after another crew had muffed a level loop and couldn’t find their blunder. We set up the HP on a hill and shot all the TPs. The location of the bust was located within a half hour…and nobody ‘reran’ the loop. Electronic determination of elevations had been used in a practical setting. This was 1979.
It took a good number of years for a lot of surveyors to actually depend on elevations determined by merely measuring a slope distance and a zenith angle. Nowadays we don’t even think about it. Solo operators and their robots depend on this technology a great deal I would think. Of course keeping track of target height can be a challenge at times, but the human factor has always been the toughest thing with which to deal.
So if someone is going to consider me a ‘pioneer’ all I can say is you’re welcome. Guys like me are the reason some trucks don’t even carry levels regularly. And in those case the level rod has been reduced to some lowly, really crappy work. 😉
And if you think the development of the EDM and total station was the BIG deal of the last part of the 20th. century for surveyors; this old ‘pioneer’ will argue the point. While all that stuff is neat, the BIG thing was the development of the data collector. Filling up a field book with a description, point number, azimuth angle, horizontal distance, and then some sort of “Z” got really tedious. And then reducing all that info was drudgery.
God bless the man that invented the data collector…
Log in to reply.