Network corrected real-time is a technological approach to high precision GPS/ GNSS positioning that has been theorized about, studied, experimented with, and implemented in various academic, scientific, and commercial forms for nearly a decade.
Click Here to begin the series,
or view the Article PDF's Here
Test Yourself
Got Answers?
Test your knowledge with NCEES-level questions. Start HERE
Meet the Authors
Check out our fine lineup of writers. Each an expert in his or her field.
A 3.868Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE
Rarely has the influence of one individual made such an impact on the history of American mapmaking. Under the direction of Henry Gannett, Chief Geographer of the United States Geological Survey, an era of unprecedented topographical maps was introduced to the United States beginning in the late 1800s.
Although hundreds, or perhaps even thousands, of visually appealing maps had already been produced by various map makers, they often lacked one essential detail -- accuracy. Beginning with surveyors working in the field, Gannett brought forth a new system of topographical mapmaking. Cartographers were primarily using visual representations to approximate the location of features in the general areas in which they actually existed. With the use of latitude, longitude, and sea-level-based elevations, each area of the country could now be eventually interconnected into one vast system, regardless of where the specific mapping was currently being done.
The Gannett family arrived in America around 1638, with Henry Gannett's pedigree directly tied to ancestors who were Pilgrim passengers of the Mayflower. Through hard work and a strong determination to continually improve upon established ideas, the Gannett surname eventually rose to prominence.
Henry Gannett was born at Bath, Maine on August 24, 1846. At age 20 he attended Harvard College and received his Baccalaureate of Science in 1869, the equivalent of a present-day civil engineering degree. One year later he received a degree in mining engineering from Hooper Mining School. While working at the Harvard Astronomical Observatory, Gannett accompanied Professor Pickering to Spain to observe the 1871 eclipse of the sun. Upon his return to the United States, Gannett was offered a position as an astronomer on Captain C. F. Hall's North Polar Expedition. Almost simultaneously he was also offered a position on the famed Ferdinand V. Hayden expedition to the Yellowstone region. Gannett chose the latter and was appointed topographer for the western division of the Hayden Survey until 1879. Many previously uncharted areas of Wyoming and Colorado were revealed in detailed text and maps in the Hayden reports, which were some of Gannett's his first published works.
While involved with the Hayden Survey, Gannett gained valuable experience in the latest mapping techniques while also enjoying the outdoors, which appealed to his personal taste. On July 26, 1872, Gannett and others in his party ascended a yet unnamed mountain with surveying instruments to reach the summit. Working ahead of the rest of the team, and as a thunderstorm was approaching, Gannett came within 50 feet of the summit when he began to feel a tingling or prickling sensation in his head and also at the ends of his fingers. Soon the sensation increased to pain and his hair began to stand on end. Others in the party arrived and also experienced the same sensation with a crackling noise surrounding them. Despite the danger, one man determined to reach the summit, but was stopped short by a severe shock each time he tried to advance. Even after retreating to a safer area a few hundred feet below the summit, the men continued to hear and feel the electricity. Gannett then affixed the name "Electric Peak" to the summit that his party had unsuccessfully tried to reach. (Electric Peak is the highest summit in the Gallatin Mountains, a small range in northwestern Wyoming and southern Montana). Two years later, while still working with the Hayden Expedition, Henry Gannett married Mary E. Chase on November 24, 1874.
The quality and accuracy of his topographical and geological surveys brought the young Gannett to immediate prominence among his peers while working for the various government agencies. Although not widely known, it was Gannett's criticism of the existing system of having separate agencies doing similar work that was a key factor in consolidating the Hayden, Wheeler, King and Powell surveys into the United States Geological Survey in 1879. No longer would competition exist for Congressional support or federal funding that had created jealousies, friction, and the lack of shared information that had unfortunately become standard among the various agencies. Gannett wanted the naming of the new organization to also have the word "geographical" in addition to the word "geological" which would have instead made it known as the United States Geological and Geographical Survey. Although the United States Geological Survey had become the official name for the agency in 1879, Hayden's reports had already been published under the geographical survey name at least six years previously.
Gannett's first role in the Geological Survey under Director Clarence King was geographer for the Tenth Census of the United States in 1880. He laid out nearly 2,000 enumeration districts with such precision that for the first time each census enumerator knew in advance the metes and bounds of his particular district. Upon the completion of this work, the new Director J. W. Powell appointed Gannett Chief Geographer of the Geological Survey on July 1, 1882. This appointment resulted in what has historically been accepted as the origin of true topographical work in the United States (previously the work had been more preparatory and reconnaissance-gathering in nature).
In 1883 Gannett was one of six founding members of the famed National Geographic Society. He became the Society's first secretary, then treasurer, then vice-president, and finally president in 1909. There was perhaps no other founding member who dedicated so much of his personal expertise to the realm of geography. Under his leadership he organized expeditions to places like Mount Pelee and La Soufriere in the West Indies, trips to the Polar Seas, and excursions to Alaska and Peru. From the very beginning he was a member of the Society's Board of Managers and later headed the Committee on Research.
Gannett was a statistician by nature and enjoyed compiling facts and figures into an organized format for others. His professional writings comprise more than 50 publications which were mainly in the form of Bulletins for the Geological Survey. His first published work for the Geological Survey A Dictionary of Altitudes in the United States came in 1884, and included all of the known elevations in the United States. At the time, it was considered a highly valued piece of information to associate an elevation with a particular point within the confines of our borders. Gannett's work is this realm is remarkable in that he not only listed all known elevation locations, but he also listed the sources for the elevations, whether through an explorer, a railroad, or a government agency. By 1906 the publication had been updated four times. Through this work Gannett was very instrumental in persuading many railroad companies to revise their datums so that their profiles would each interconnect with each other. Often railroads were using assumed or local datums, and Gannett helped direct them to using sea-level-based datums. His work with elevations also led to a published paper on the average elevation of the United States and also of each individual state.
In 1885 he published Boundaries of the United States and of the Several States and Territories, with a Historical Sketch of the Territorial Changes. In this publication Gannett detailed the boundaries of our country and of each individual state describing how each portion was formed and the year that boundaries were changed. By 1904 this publication was in its third edition, since many state boundaries were still being fixed into place.
In 1887 he began the use of the planetable for platting topographical features directly in the field as they were being surveyed. He implemented a system of using vertical angles to quickly carry elevations, and brought forth the use of the transit and steel tape for traverse and triangulation, which had formerly been only known to the Coast & Geodetic Survey. Contouring in the field instead of the office was another one of Gannett's improvements that contributed to quickness, accuracy, and economy of the work being done.
Gannett was chief geographer during the eleventh and twelfth censuses of the United States taken in 1890 and 1900. He was the first American to clearly see how statistics and topography were directly related. He was also in charge of censuses in Puerto Rico, Cuba, and the Philippine Islands.
One of Gannett's finest works came in 1893 with the writing of A Manual of Topographic Methods. Prior to the publishing of this book there were no set rules to govern the methods being used to perform topographic surveys. Gannett's manual would become the authority for field crews when the topographical quad sheets were first being introduced. The book covered everything in detail from contours to the use of the various surveying instruments. Because of advancements in technology, he expanded and republished this title in 1906.
Gannett, along with Dr. T. C. Mendenhall of the Coast & Geodetic Survey, organized the Board of Geographic Names in 1890, with Mendenhall becoming its first chairman and Gannett succeeding him in 1894. He held that position for twenty years. This board endeavored to identify a single common name for thousands of locations and put an end to various maps with conflicting names. Their findings also worked to quickly identify the many new towns that were rapidly being formed with western expansion, and eliminated multiple or similar town names existing in the same states. This published work was extensive and gave the name origins for the majority of the cities, towns, rivers, and prominent locations in the United States. Perhaps the greatest challenge was that of the many disputed locations in Alaska that had been the result of Russian, English and Spanish sources. The greatest benefactor of this work was the postal service in days before the advent of the modern Zip code. A publication titled The Origin of Certain Place Names in the United States was one result of this extensive research.
In 1895 Gannett co-authored Commercial Geography, which was at once recognized as the authoritative text to be used in schools and colleges. The same year he authored The Building of a Nation, based upon the results of the 1890 census. It presented an impressive statistical picture of the nation as it had grown throughout history. In the final chapter of this work, Gannett made a series of predictions, many which turned out to be quite accurate (such as future problems due to the destruction of natural resources, the damaging effects of unrestricted immigration, and the prominent roles that women would eventually take on in our nation).
Gannett's last year in the role of Chief Geographer (a title also known as Chief Topographer) for the Geological Survey came in 1896, and it was marked with one of the greatest lasting achievements for surveyors. During this year permanent survey monuments began to be placed during topographical surveys, which Gannett knew would be of great importance to future surveys.
When in 1897 the Geological Survey was assigned the task of documenting the forest reserves of the United States, Gannett was placed in charge of the examination work. Likewise in 1908, when the country's natural resources were documented for location, quantity, and expected life span, Gannett was selected to oversee and edit the reports. His work in the forest reserves are of great benefit to surveyors when searching for bearing trees since the life span and rate of growth of many species were documented.
Gannett's interests were continually expanding, but all were directly related to the advancement of American geography. In 1901 he published a document on the profiles of all of the major rivers in the United States. He always seemed to take statistics one step further and compiled them into charts and maps that the average person could readily understand.
Gannett was a founder of the American Association of Geographers, a scientific and educational society begun in 1904. Today its 10,000 members share interests in the theory, methods, and practice of geography.
Gazetteers containing important information about places and place names were published between 1898 and 1906 by Gannett for the states of Colorado, Delaware, Kansas, Maryland, Oklahoma, Texas, Utah, Virginia, and West Virginia as well as Cuba and Puerto Rico.
The highest peak in Wyoming, Gannett Peak, located in the northern Wind River Mountain Range on the Continental Divide, was named in honor of Henry Gannett in 1906. Many modern-day mountaineers rank Gannett Peak as the most difficult peak to climb in the Continental United States. Gannett was one of the first to ascend to the top of Mount Whitney in California. In Alaska he discovered and christened many mountain peaks and hidden lakes that had never before been placed on any maps.
When Commander Robert E. Peary announced he was the first to reach and discover the North Pole in 1909 amid the controversy of Dr. Frederick Cook's simultaneous claim, Henry Gannett was chosen chairman of a special committee to examine and verify Peary's records.
During his career as Chief Geographer for the Geological Survey, more territory was mapped by the United States Government under his supervision than was ever mapped under any other man. Many of his colleagues referred to him as "The Father of Government Mapmaking". His younger brother Samuel S. Gannett was also actively engaged with work for the Geological Survey and also published several works compiling statistical survey-related information, as well as being the surveyor involved with reestablishing several state boundaries.
Henry Gannett's interests were broad and encompassed many areas of geography in the United States. Other published subjects by Gannett were primary triangulation networks, known latitude and longitude positions, magnetic declinations, estimations on coal production, and the distribution of rainfall. He continually wrote articles for scientific magazines and for more than 30 years contributed to the work of the encyclopedias being published. He was also a member of the Royal Geographical Society, the Scottish Society of Geographers, the Geographical Society of France, the American Statistical Association, and was secretary of the Eighth International Geographic Congress in Washington.
Gannett rarely spoke of his own achievements, but rather preferred to honor his fellow scientists and laud the work that they were doing in the realm of geography. His convictions were founded upon his thorough research, and he rarely offered opinions without scientific data to back them. His eagerness to point out the waste of time and energy in early mapmaking techniques and his providing of more accurate solutions propelled the United States Geological Survey into greatness. USGS would likely be only a shadow of what it has become had it not been for Gannett's involvement.
Henry Gannett died on November 5, 1914, at the age of 68. When one reflects on his many accomplishments, it is hard to fathom that it was the work of just one individual. Gannett set the bar very high for the Geological Survey, the National Geographic Society, and for the many other organizations with which he was associated. His many published documents bear witness to the fact that he endeavored to share with the rest of the world for generations to come the things that had become his passion.
Jerry Penry is a Nebraska licensed land surveyor and a frequent contributor to The American Surveyor.
A 3.868Mb PDF of this article as it appeared in the magazine—complete with images—is available by clicking HERE
Share this page with your favorite social networks!
American Surveyor Recent Articles
Editorial: Setting Our Sights
Years of planning and construction went into Beijing's iconic bird's nest stadium that is now synonymous with 2008 games. With Vancouver slated to host the Winter Games in 2010, surveyors have been hard at work helping to ready the infrastructure. Diversifying: For those of you looking for .... Read the Article
Point to Point: Boundaries by Acquiescence
We retracement surveyors, for the most part, labor within a stable and consistent part of the law. By this, I mean that from place to place, and over time, there is little variation in the doctrines defining correct practice. Monuments, everywhere, trump courses and distances, in the event of .... Read the Article
WowFactor: The Trimble VX Spatial Station
It's not unusual to find a digital camera as standard equipment for a survey crew. Providing photos of monuments, project sites and other evidence is a routine part of the surveyor's work. Nowinstead of a flat drawing and some simple snapshotsimagine giving your client a 3D walkthrough tour of ... Read the Article
Vancouver Trains For Olympic Games
More than one million athletes, judges, volunteers and visitors are expected to converge on Vancouver, Canada, and surrounding areas during the 2010 Olympics. Yet many of these visitors won't realize the Olympic-sized engineering and ... Read the Article
Tips & Tricks: Getting More from Your Handheld GPS Unit
Are you getting all that you can from your handheld unit? Are you able to directly observe State Plane coordinates with your handheld? Although inexpensive units may not have a selection for the State Plane coordinate grid that you use in your state, if your State Plane Coordinate Zone uses the .... Read the Article
Survey Reports: Preparing a Survey Report—Part 5
This is the fifth and last article in a series of articles suggesting formats and contents of a survey report. Previous articles dealt with opinions on the location of corners and boundaries [Feb. 2008]; encroachments, gaps and overlaps [Mar. 2008]; limitations of the surveying services [June 2008]; and.... Read the Article
RTN101: Monitoring with RTN (Part 15)
Monitoring is essentially tracking movement over time and is often part of a surveyor's regular line of business. Such tasks are known by many names: subsidence monitoring, deflection monitoring, deformation monitoring, structural integrity monitoring, compliance monitoring, and ... Read the Article
Product Review: Spectra Precision FOCUS 10
The Spectra Precision's FOCUS 10 brings back a lot of memories from an instrument I reviewed several years ago. Without a doubt, the FOCUS 10 has benefited from the former, but is updated and less expensive even in terms of 2002 dollars. And that's a good thing, since ... Read the Article
ProFile: Marshall Robinson
We allow little time in our day-to-day schedules to get to know people much beyond their shells. It was therefore a pleasant change of pace when I received a phone call awhile back from Marshall Robinson, who was calling to order a map from our website ... Read the Article
Vantage Point: Tough Times
The construction slowdown has hit different parts of the country with varying ferocity. The latest jolt to "life as we know it" is a uniform blow to businesses of all sorts, and has the potential to change the financial plans of a number of surveying firms. Within a week, three U.S. motor vehicle ... Read the Article
Surveyors Report: Mimi the Elephant
Years ago I worked for a medium-sized private engineering firm in Denver. We negotiated a continuing services contract with the City and County of Denver for surveying services, and my crew was elected to conduct this work. The City was understaffed by one crew for ... Read the Article
• 15th Annual GeoTech - October 7-8, 2008, NOAA’s Auditorium and Science Center in Silver Spring, MD. Hosted by Potomac Region of the American Society of Photogrammetry and Remote Sensing and co-hosted by the NGS, 1 day of Workshops taught by experts, and 1 day of Technical sessions.,
• GITA's First Annual GIS for Oil & Gas Conference - Calgary - Nov. 6-7, 2008, Calgary Marriott Hotel, Calgary, Alberta, Canada. The GIS for Oil & Gas Calgary Conference will build on the momentum from GITA’s GIS for Oil & Gas Conference held in Houston, Texas, every September.
• GITA's “How to Financially Justify Your Geospatial Projects” Two-day Workshop - Nov. 13-14, 2008 in Denver, Dec. 11-12, 2008 in Tampa. All types of organizations now have a unique opportunity to learn from GITA’s landmark research project, “Building a Business Case for Geospatial Information Technology: A Practitioner’s Guide to Financial and Strategic Analysis.”
• Geography in Las Vegas - March 22–27, 2009. Join 8,000 geographers, GIS specialists, and environmental scientists from around the world in Las Vegas for the very latest in research, policy, and applications in geography, sustainability, and GIScience, during the annual conference of the Association of American Geographers.
• California Land Surveyors Association 2009 Conference - March 28-April 1, 2009, Hilton San Diego Resort (Mission Bay).
This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
, (707) 578-6016.
• SPAR 2009 - March 30- April 1, 2009, Hyatt Regency Hotel, Denver, Colorado. SPAR 2009 will focus on best practices for using 3D imaging technologies to design and deliver capital projects as well as operate, modify and maintain production, manufacturing and infrastructure assets.
AMERISURV TOP NEWS
Are you getting our e-newsletter?
Sign up and check out the archives HERE
Reach our audience of Professional land surveyors and Geo-Technology professionals with your career ad. Feel free to contact us if you need additional information.