RTN expert Gavin Schrock provides everything you need to know about network-corrected real-time GNSS observations.
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Meet the Authors
Check out our fine lineup of writers. Each an expert in his or her field.
A 54Kb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE
Solo Surveying
In response to the "Attitudes of Independence" article [Winter 2004], why run an entire article on the Robotic only to dismiss it in the final paragraph? I own a small surveying firm that uses Trimble Robots and Topcon GPS. In my opinion there is no better solution. But I do not work alone!
Working alone is no fun. That's why we do this isn't it? Having a skilled employee to assist is a must. Now I could do most of the work myself, but it takes me three to four times as long to do anything and I can't make money like that.
The robot is the best instrument I've ever used in the woods. It can get shots that I could never see through the scope. But, I have someone pointing the instrument at me when doing this and it just locks on. When I topo, I have the data collector and my partner has the rod. Ever carry a rod with a radio and a data collector all day? There have been times I topoed by myself.
Using our custom-made data collector (HP 49) I topoed 1000' of roadway from back of walk to back of walk, 75% of it curve at 25' sections in one hour. All line worked and coded separate. Ever use a robot for levels? It can't be beat. I haven't used a level in over a year. And that was to check what I was doing with the robot. I'm going to stop now. This could go on for a while . . . —Robert Martin, LS
Via the Internet
Editor Replies: You state your point well. My interpretation of the final paragraph of that article, however, was that the author was simply sharing "the rest of the story" concerning two individuals and their experiences with robotics.-MC
Heliotropes
I enjoyed the very interesting article regarding heliotropes by Silvio Bedini [November 2004]. This article brought back some recollections of the period when I was working for Fairchild Aerial Surveys in the early 1960s in Los Angeles. Fairchild Aerial Surveys was in the aerial photography and mapping business from the early 1920s until they were acquired by Aero Service Corporation of Philadelphia in about 1965. During a brief time between field assignments, I was assigned the task of cleaning out some of the old storage areas in the headquarters building in downtown Los Angeles. It was there that I ran across some of these very unique heliotropes.
Their parent company, Fairchild Camera and Instrument, had constructed some automatic heliotropes (Fairchild Aerial Surveys Automatic Heliotrope) probably during the 1930s. They consisted of a geared motor driven base section about 8" in diameter that was usually mounted on a fairly heavy tripod. The revolving base had an upright section containing four mirrors which revolved about a horizontal axis on standards about 10" above the base. The mirrors were about 3" or 4" square. The base had a solar activated switch that only energized the unit when the sun was shining. The unit was covered with a primitively constructed clear Plexiglas type material that consisted of a wire sewn cylinder section capped by a wire sewn dome section. Some of the later units had cemented Plexiglas sections that were quite well done.
These units were used for long-range triangulation jobs. The crew would have to take the unit, tripod, batteries, electric fence and fence posts up to the station to be used. The electric fence was used to discourage cattle or other critters from getting too close to the tripod. Once there and set up the unit would continue to produce flashes (4-6) every 30 seconds or so as the mirrors rotated in both axes. I understood that the batteries would last over a week in most cases with normal periods of sunshine. I never used one and only spoke to some company surveyors that had worked with some "old timers" who remembered taking them into the field.
These were impressive units and I even had one (it never reached the trash bin with the others I had to dispose of) but it was apparently lost during one of my moves. This was a very well made but somewhat noisy unit that served a purpose of having a site observable over very long distances during daylight. I hooked up a 6-volt lantern battery to the one I salvaged and it ran well after years of storage. I was even able to find a picture of this instrument in an early edition of Davis and Foote, 4th edition, McGraw Hill, 1953. —John Ostly, LS
Via the Internet
A Stadium Rod
The following was submitted by Maine surveyor Richard Hale. In Richard's cover letter, he explained that Phil Coolidge was an excellent forester, a fixture at every Society of American Foresters meeting, and had many stories to tell. He was tall, thin, always well-dressed, and easily recognizable for his habit of walking with his hands in his back pockets, coat wide open, winter or summer. He wrote History of the Maine Woods in 1963 and a monograph, Park Holland--Revolutionary Soldier, Maine Surveyor in 1967. This story was told to Richard by Paul Atwood, a consultant who was a P.E., licensed forester, surveyor and architect:
Phillip Coolidge was a Forestry Consultant in Bangor, Maine for many years. He was a graduate of Harvard College and the Yale School of Forestry (c. 1908), a true pioneer in the profession. In a state that is 90 percent forested, in the past, many foresters worked in land surveying. Phil was in court as an expert witness involving a family fight over the volume removed from a gravel pit. Judge Murray who was hearing the case, had degrees not only in law but in chemistry and engineering. He was also a longtime friend of Phil. The testimony went approximately as follows:
PC: I had my instrument man set up in the bottom of the pit, and I went up the bank with a stadia rod for him to take readings. Judge: You are saying that you had two rods, one in each hand? PC: No, I had one rod. A stadia rod is a surveyor's graduated rod from which readings can be taken. Judge: Mr. Coolidge. You are a graduate of Harvard College. Is that correct? PC: It is. Judge: While you were at Harvard College, did you take four years of Latin? PC: Yes, I did. Judge: Mr. Coolidge. Stadia is plural. I believe you had a stadium rod in your hand.
From then on, if Phil slipped and said "stadia," the judge gently corrected him.
A 54Kb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE
Editorial: CGSIC in Savannah
The 48th meeting of the Civil GPS Service Interface Committee (CGSIC) was held September 15-16, 2008 in Savannah, Georgia. Of particular note was the announcement that NDGPS will continue. Funding is still a challenge, but the powers that be have decided that NDGPS, like GPS, is .... Read the Article
Point to Point: Relatively Speaking
Sooner or later it happens: one of your friends or relatives asks you to survey their property, or otherwise act professionally on their behalf. Is that all right or do we have a higher obligation to the public concerning impartiality? Although I have not conducted an exhaustive examination of the .... Read the Article
More Than a Simulation
When work such as land surveying requires precision and gets impacted by changing technology, it makes sense to be introduced to high-tech equipment on an actual project rather than on a simulation exercise or in a classroom setting. That runs counter to ... Read the Article
Optech Incorporated: The Lidar Company
In the early 70s, Dr. Allan Carswell, a physics professor at York University in Toronto, developed a pulsed laser system used in the world's first lidar bathymetric mapping system. Based on his research, Carswell founded Optech Incorporated in ... Read the Article
The Wow Factor: SmartWorx from Leica Geosystems
Every version of Leica Geosystems software contains user requested features. The latest product request that made the final cut was a "Field to Office" application. This full-featured FTP and transfer software is now built into the operating system of all System 1200 sensors, making it possible for .... Read the Article
Visualizing N G S Control Stations in Google Earth
Google Earth is rapidly becoming the land surveyor's tool-of-choice for preliminary job site reconnaissance and survey planning (see "Topography is Dead," by Joel Leininger, March 2007). Survey projects often begin with the investigation and .... Read the Article
Surv-Fi, Part 2: Boomer's Hearing
Stand back from the cradle Hector!" Vel warned her colleague. "You could receive a rather nasty static shock as it spins up!" Hector Fontecilla stood shivering in the still Chilean Patagonia morning awaiting instructions from Vel Kawashima. Ten thousand ... Read the Article
Tips & Tricks: Hidden Point Offset
Let's say it's 5:30 Friday afternoon and you're past ready to call it a week. You've just calculated the angle and distance to look for one of the last monuments you need to tie in. You turn the instrument to the angle and shoot a distance that measures just behind a tall tree. After a few minutes' search ... Read the Article
FeedBack
Wendy, quite possibly the best article ever written in a surveyor's journal ["If Not Now, When? Sept. 2008]. It matters not how technically proficient we are, how much money we make or how well "esteemed" we seem to be in our profession when we face serious illness or death. What do our friends and ... Read the Article
Vantage Point: Diversions in the Park
There is not a lot of unused land in our urban and increasingly suburban areas. It disappears under shopping centers and houses and roadways at a rate unimaginable a century ago. So it may not be unusual to start eyeing land that was set aside for parks and open space at ... Read the Article
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