Surveying

Solar Flares and Surveying Accuracy

The Ordnance Survey Blog explains why “space weather” — such as the coronal mass ejection the Sun let loose this weekis bad news for mapmaking: solar flares disrupt navigation satellite accuracy.

During a space weather event, sat nav users may experience a loss of satellite signal or errors in position. During the last big solar storm in October 2003 position shifts of greater than 10cm horizontal and up to 26cm vertical were recorded in higher latitude northern Europe - not such a big deal for drivers, but that it makes map making a lot more difficult!

So don’t panic about your in-dash GPS — it’ll get you just as lost as it always has.

This is probably a good point to mention, since some people are wondering whether they can see the aurora borealis from their location, that I posted a link to maps of auroral activity last August.

Two New York Times Articles About LIDAR Mapping

The New York Times had two — count ‘em — two articles on using LIDAR as a mapping tool earlier this month.

This article is about using airplane-based LIDAR to map the topography of New York City: “The data will be used, among other things, to create up-to-date maps of the areas most prone to flooding, the buildings best suited for the installation of solar power and the neighborhoods most in need of trees.”

And this one is about using it to map Mayan archaeological sites despite dense jungle cover: “In only four days, a twin-engine aircraft equipped with an advanced version of lidar (light detection and ranging) flew back and forth over the jungle and collected data surpassing the results of two and a half decades of on-the-ground mapping, the archaeologists said.” Via Boing Boing.

Previously: Portland LIDAR Survey.

China Maps Antarctica

A Chinese expedition is set to produce the first land cover map of Antarctica by the end of this year, Xinhua reports. “The map, with the application of high resolution remote sensing technology, will for the first time in the history show the distribution of key features on the continent, including sea ice, snow, blue ice, rocks, soil marshes, lakes and ice crevasse.” They’re also making use of U.S. Landsat imagery. When did China start getting interested in Antarctica? Via Spatial Sustain.

So What If Four Corners Is a Little Off?

It’s not that the Four Corners marker is “about 2.5 miles west of where it should be,” as the Deseret News puts it, it’s that it’s about two and a half miles west of where it should have been. Important distinction. Surveyors were aiming for 37° N 100° W when they placed the first marker in 1868; and modern-day observers with GPS receivers can easily spot the discrepancy. Doesn’t mean the borders are going to be redrawn. There are plenty of surveying errors along the U.S.-Canada border that are now accepted as fact, for example.

‘Cartography from a Kayak’

University of Tennessee researchers are collaborating with the National Park Service to map the streams of the Big South Fork National River and Recreation Area and the Obed Wild and Scenic River, the Knoxville News Sentinel reports. Their goal is…  •  Continue reading this entry.

Mapping the Gamburtsevs

An international scientific expedition has wrapped up its mission to map the Gamburtsev Mountains. What’s the twist? The Gamburtsevs are in Antarctica — under up to four kilometres of ice. The mapping was done seismically, as you can well imagine….  •  Continue reading this entry.

Mapping Rural China

Never mind Navteq or Tele Atlas agents scouring the suburbs for new streets — how about Xinjiang’s army mapping service trying to keep up with rapid rural development in China? Via All Points Blog….  •  Continue reading this entry.

The Ordnance Survey in 1953

An excerpt from a newsreel about the latest technology used by Ordnance Survey mapmakers — in 1953. “It used to take two men a whole year to do the mapmaking mathematics that these adding machines and electronic computers can…  •  Continue reading this entry.

Cadastral GIS Horror Stories

On the Surveying, Mapping and GIS blog, Dave Smith recounts some GIS horror stories involving cadastral data errors — and the ludicrous things that are done to resolve them. “If you have discrepancies, data gaps, quality issues, other issues, I…  •  Continue reading this entry.

Ed the Map Maker

This is an article celebrating 40 years of service by Ed Maslonka, the cartographer of Grand Island, Nebraska, but it also offers a taste of what goes on, mapping-wise, in municipal planning departments….  •  Continue reading this entry.

The Discovery of France

Last week, the National Post website ran a three-part excerpt of Graham Robb’s new book, The Discovery of France: A Historical Geography from the Revolution to the First World War. Of interest to us is the second part, an amusing…  •  Continue reading this entry.

Moses Greenleaf Biography

Retired University of Maine professor Walter Macdougall has written a biography of early Maine surveyor and mapmaker Moses Greenleaf, the Bangor Daily News reports. Macdougall’s book, Settling the Maine Wilderness: Moses Greenleaf, His Maps, and His Household of Faith, 1777-1834,…  •  Continue reading this entry.

The Bowman Expeditions

Kansas University geography professors Jerome Dobson and Peter Herlihy are trying to put geography back on the map (so to speak) after a long, post-WWII decline by proposing series of expeditions — the Bowman Expeditions — that would collect…  •  Continue reading this entry.

Getting Out from Behind the Wheel

If you’ve been following this blog’s entries about how digital mapping data providers compile their data (see the Surveying category archives), you’ll know that since time immemorial — or at least the 1940s — mapmakers have compiled their road data…  •  Continue reading this entry.

Caught Mapping (1940)

Caught Mapping is a nine-minute film, made in 1940, about how the road maps of the time were made — and, more importantly, revised, with a fair bit on field surveyors. I was surprised that the film reported that…  •  Continue reading this entry.

Again: Navteq in San Diego

Still another profile of a digital mapping data provider’s employees as they survey the streets of (insert your town name here): this time it’s Navteq in San Diego. Via Cartography, with whom I’m in agreement: where are all these stories…  •  Continue reading this entry.

TeleAtlas in Santa Fe

Another article on field data collection by the digital mapping data companies, this time from the Santa Fe New Mexican, looking at TeleAtlas’s work scouring the streets of Santa Fe. Via All Points Blog. See previous entries: More on Digital…  •  Continue reading this entry.

CNet Profiles TeleAtlas

CNet’s Elinor Mills profiles TeleAtlas, one of several mapping data companies that provide the online map services with their data (along with NAVTEQ, for example, they provide data for both Google and Yahoo!). The article looks at data collection and…  •  Continue reading this entry.

Maps in Our Lives

Through January 6, a Library of Congress exhibition in the corridors of the Madison Building called Maps in Our Lives: “The exhibition explores four constituent professions represented by ACSM [the American Congress on Surveying and Mapping], the nation’s primary professional…  •  Continue reading this entry.

Russian Geodetic Datum Point Preserved

Russian cartography enthusiasts have managed to save what I think is a geodetic datum point, used in the mapping of Russia during the 19th century, the St. Petersburg Times reports. Such points were the basis around which topographical maps were…  •  Continue reading this entry.

A Few Pages About Theodolites

Theodolites are surveying equipment used in triangulation. They’ve turned up on a couple of web pages recently: Ethel the Frog wants to know how to use one, and Languagehat looks at the origins of the word (see also)….  •  Continue reading this entry.

19th-Century Surveying and Mapping Equipment

The Topographical Engineering Detachment — they’re sort of an SCA for 19th-century U.S. Army engineers — has this dead-interesting page of surveying and mapping equipment from the 1800s. Old photographs and descriptions. Via ba’s comment on MetaFilter….  •  Continue reading this entry.

Triangulation Pillars

Another article from Nicholas Crane based on his BBC series, “The Map Man” — this time in the Telegraph. This one’s about the Ordnance Survey’s triangulation pillars, the use of which in surveys eventually resulted in a series of one-inch-scale…  •  Continue reading this entry.

Backcountry Mapping

Last year there was a story about the people on the ground who do the surveying for the online mapping services (see previous entry). Now there’s a story about the people who do something similar in the middle of nowhere,…  •  Continue reading this entry.