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In This Issue • Editors Corner • Surveyors in History • GPS at LSU: • Robotics and RTN • A Visit to Nedo • Careers in Survey and GIS • Wish List for Risk MAP • Search For Confluences
Long Term Almanac, or, what to do when you can't use your total station and GPS
Written by Geoff Miller
Tuesday, 21 April 2009
This is a great story about what to do when you can't use your total station and GPS. It's also a lesson in astronomic surveying.
An Introduction to an Old Almanac
"Dagnabit!" Denny Carswell muttered as he kicked more gravel into the ditch. This was supposed to have been an easy job. Simply part-off a portion of the Otero ranch for sale to some fellow from Albuquerque. Denny had visited Luis Otero back in August to set two corners along New Mexico FR 402. He'd measured-off the appropriate distance from the centerline of the road to the edge of the easement and then driven-in the rebar stakes where the owner had wanted them. These, together with two rock cairns along the back of the property were to define the parcel. Old man Otero and Denny had then walked the lot taking compass bearings and pacing distances. The gentle terrain and sparse distribution of piñon and juniper trees seemed to ensure that the official traverse would go quickly. Denny had known Luis for many years and, although he was busy, had agreed to accept the job and plat the parcel by November 1st. It was now October 18th and he was finally able to take a break from the power-line survey to come and finish this one.
However, as his assistant Greg had noted 5 minutes ago, things had sure gone to 'infierno' in a handbasket. By 8 AM they had driven the 20 miles of forest service roads from San Benito to the Otero ranch only to find that FR 402 had recently been graded. "Just plain dumb luck" Denny thought. "They probably hadn't graded this road in 10 years." The "A" corner (refer to Figure 1) had been bent but still appeared to be in its original location. Denny always used 36" x 5/8" bar in his work and he had driven this one in deeply. His other rebar corner however, had vanished. The blade of the grader had obviously strayed onto ranch property and, in doing so, thrown a wrench into the survey. To make matters worse, Greg had just discovered that the GPS was dead. Denny had dutifully charged it the night before, but the announcement of its impotence hadn't surprised him. He'd noticed that it hadn't been holding charge well in the last few weeks. Whether the problem lay with the battery or the charger was the only question left in his mind but, darn it, replacing either would be expensive. "Double dagnabit" he said, kicking another rock...
To download a 157Kb Word doc of the rest of this 12,000+ word article (including illustrations) click HERE
The almanac itself is five pages, and a 331Kb PDF can be downloaded HERE
A “Fixed” Fight: A peek inside one construction expert’s campaign to make fixed-price contracts and cost containment the industry’s new normal: Huge cost overruns and missed deadlines have long been the accepted norm for construction project operations. But as the economy struggles to fully recover, construction expert Barry LePatner stresses that these precepts can no longer define the nation’s most inefficient industry. He provides a proposal for hardwiring construction cost containment into future projects.
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