Author: rothelandsurveyor
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The First Thanksgiving
In autumn of 1621, the Plymouth colonists and Wampanoag Indians shared a harvest feast that is now acknowledged as one of the first Thanksgiving celebrations. The Mayflower had left Plymouth, England in September 1620 carrying 102 passengers – an assortment of religious separatists seeking a new home where they could freely practice their faith, and
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Carlson Post-Processing
Of interest to anyone who has ever done GPS/GNSS post-processing, Carlson Software Inc. is introducing the Carlson SurveyGNSS Post-Processing program. Bruce Carlson, president of Carlson Software, notes that this addition will help "make our survey product line the most extensive in the industry, from field data collection through all forms of processing to as-built mapping
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Accuracy in Mapping
How accurate is your map? How do you determine or define the accuracy of your map? There's an old adage: "The man with one clock always knows the time; the man with two clocks is never quite sure…" This reminds us of the simple truth that virtually every clock has some error, and is not
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Skybox Satellite Imagery
In Professional Surveyor's Pangaea series, article #94 informs us about the Skybox satellite imagery project. Skybox Imaging is a Silicon Valley startup, with plans to launch a constellation of 24+ low-cost microsatellites, working toward the goal of lowering prices and increasing the accessibility of high-resolution satellite imagery. Their smaller satellites cost a fraction of current
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What Really Is WGS-84?
For any of you in the surveying business, WGS-84 is probably a regular part of your vocabulary, but in his GPS World article entitled Accuracy, Datums, and Geospatial Data…, Eric Gakstatter cautions to the contrary, stating the following: "First, let me begin with the statement that WGS-84 should not be in your geospatial vocabulary. In
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Ortho Imagery: Pay or Free?
Good quality ortho imagery is readily available today, unlike the mid 1980s when the only folks who had geo-referenced imagery were the intelligence agencies. But is today's freely-available imagery your best choice? On the other hand, is fee-based imagery worth the price? In this Geospatial Solutions article, Art Kalinski explores imagery sources, both
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Space Weather, and Real-Time CORS Streaming
For anyone interested in the current "solar maximum", Eric Gakstatter of GPS World shares his experiences at the Space Weather Workshop in Boulder, Colorado. The current Solar Cycle 24 has been weaker than expected, but the most extreme geomagnetic storms have historically occurred after the solar maximum, so the next two years may still hold
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Galileo Satellites Telling UTC Time
So how long is a nanosecond, or a billionth of a second? By comparison, a typical lightning flash lasts about 10 milliseconds, or 10,000,000 nanoseconds. So when we say "time flies", the nanoseconds are, indeed, flying by quickly! But highly precise time is critical to accurate GNSS position calculations. This GPS World article reports how
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What Does it Mean to Survey Property?
Jeffery N. Lucas, PLS, shares his insights into this question in a recent POB article. Is a surveyor's task simply to take measurements? Very rarely is our work that simple. Is his task to simply "stake the deed"? Absolutely not, since discrepancies are common between legal descriptions and actual ground measurements. While there are some
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New GPS Satellites
Per this GPS World article, Lockheed Martin has been awarded two Air Force contracts for four more next-generation GPS-III satellites. Lockheed is currently under contract for production of the first four GPS-IIIs, which will replace aging GPS satellites while at the same time improving capabilities of the system. The Air Force plans
Rothe & Associates, PLLC 