International Surveying Competition, November 12-17, 2018 in Northern Virginia
Monday, September 17, 2018
Posted by: Khea Adams
Plans Being Finalized for International Surveying Competition, November 12-17, 2018 in the Washington, DC Area – Help Wanted!
Negotiations/preparations having begun for a surveying competition that had been proposed to NSPS by the Beijing Municipal Federation of Trade Unions in China. Now that the plan has been finalized, agreements signed, and the schedule for the competition completed, we hope that the information contained in this article will answer questions that readers may have, and provide incentive to attract those who wish to participate on the NSPS team, serve as judges, and/or contribute short-answer questions that may be utilized for the “theoretical competition”. To date, a handful of inquiries have been received regarding participation as a member of the 13-person NSPS team. Please contact NSPS Executive Director Curt Sumner (firstname.lastname@example.org
) to discuss the competition and/or to express your interest in participating in some way. The headquarters hotel for the event will be located near Dulles International Airport in Northern Virginia.
In consideration of the differentials between the types of surveying conducted in each country, the underlying basis of the competition will focus on surveying activities common to both teams. Below is a description of the “field” portion of the competition, which will be conducted on the National Mall in Washington, DC. The “written” portion of the competition will be 100 short-answer questions agreed upon by the Chinese and US delegation leaders.
Immediately below are brief descriptions of the four (4) surveying procedures that will be used in the field survey portion of this competition, as presented to the Chinese team by project coordinator Dave Doyle. There is no particular order in which they must be accomplished by each team. A note was prepared for the Chinese team noting that the positioning systems used in the United States are referenced as the North American Datum of 1983 (NAD 83) for horizontal positioning and the North American Vertical Datum of 1988 (NAVD 88) for height determination. The NAD 83 and NAVD 88 values for the three survey control marks located in the area of the competition are published.
Leveling - The most accurate methodology for the determination of the difference in height between two points. The procedure requires a leveling instrument and, generally, two graduated level staffs. A team of three surveyors is to choose what it considers to be the most efficient way to perform these measurements. The three survey control marks selected in the area of the competition have very accurate data published for them, and will be used as the starting and ending points from which each team will determine the height for their new point. The survey control marks are commonly referenced by the term “bench mark”.
Traverse - This measurement process will require the use of a total station and at least one range pole with a glass reflector. The traverse technique will allow the teams to determine the horizontal coordinates (latitude and longitude and UTM values) for their new point by measuring angles and distances from the three survey control marks. They each have high accuracy horizontal positions already published.
GNSS - These measurements will showcase each team’s ability to utilize the network of Global Navigation Satellites to independently determine the latitude, longitude and ellipsoid height of their new point. The teams will be provided at least two methods to accurately perform positioning with a GNSS receiver to validate the horizontal coordinates as previously determined by traverse, and height as performed by the leveling. Each team will have a dual frequency GNSS receiver and be provided with access to the Trimble regional real time network as well as the option of checking those values by submitting their GNSS observations to the National Geodetic Survey's Online Positioning User Service (OPUS).
Vertical Angle Observations - The final observation. Each team will set up the total station on the new point they have set, and measured with the other techniques. They will perform vertical angle observations to the point on the top of the Washington Monument, called the pyramidum to calculate the NAVD 88 value of the point, which will then be compared with the point’s published value previously determined by GNSS measurements most recently in 2013.