1. 
FGCC is currently known as___________________________. 


FGCS 


USCG 


USGS 
2. 
Global Positioning System (GPS) surveying produces a set of XYZ coordinates which can be transformed into geodetic latitude, longitude, and ellipsoidal height by using an reference ellipsoid to model the earth. 


True 


False 
3. 
A determination of a NAVD88 elevation using GPS measurements at a given point requires transformation between ellipsoid and geoid based height systems. 


True 


False 
4. 
_______________ is the reference system most frequently used with offtheshelf GPS equipment. 


WGS74 


WGS84 


WGS94 
5. 
The orthometric height of a point is the distance from the reference surface to the point, measured along the line perpendicular to every equipotential surface in between. 


True 


False 
6. 
The NAVD88 datum is the product of a horizontal adjustment of leveled height difference measurements made across North America. 


True 


False 
7. 
Geoidal heights or (geoid height values) represent the geoidellipsoid separation distance measured along the ellipsoid normal and are obtained by taking the difference between ellipsoidal and orthometric height values. 


True 


False 
8. 
The geoid itself is defined as a potential surface and natural variations in gravity induce a smooth, continuous, curvature to the plumb line and therefore physical equipotential surfaces which are normal to gravity do not remain geometrically parallel over a given vertical distance. 


True 


False 
9. 
NAVD88 elevations are not ortho metric heights that represent the geometric distance from the geoid to the terrain measured along the plumb line. 


True 


False 
10. 
The World Geodetic System of 1984 reference ellipsoid is 


Geocentric 


Biaxial 


An ellipsoid of revolution 


All of the above 
11. 
The GRS80 ellipsoid is ____________________________. 


Exactly geocentric 


Not exactly geocentric 
12. 
The geoid model is constructed ____________________. 


From a truncated functional series approximation 


Using a spherical harmonics expansion 


Using an extensive set of globally available gravity data 


All of the above 
13. 
Most recent geoid models have an absolute accuracy for _________________. 


Geoid heights of one centimeter 


Geoid heights of a few centimeters 


Geoid heights of a few decimeters 


Geoid heights of one meter 
14. 
The lowest geoid heights in the US NGS GEOID96 model are 


7.2 meters 


21.5 meters 


39.8 meters 


51.6 meters 
15. 
The geoid model GEOID96 is based on 


NAD27 


NAVD29 


NAD83 
16. 
HPGN is abbreviated as _______________________. 


High Precision Geodetic Networ 


High Probability Geodetic Network 
17. 
The geoid height is added to the published orthometric height at the GPS reference station to determine its ellipsoid height to the accuracy level of the geoid model. 


True 


False 
18. 
Once the reference stations’ ellipsoidal, orthometric and geoidal heights have been fully determined, elevations are transferred from the reference stations to the remaining points in the network according to the relation __________________. 


Hi = hi − NI 


Hi = Ni − hI 
19. 
GPS baselines are not observed to determine ellipsoidal height differences across a network of stations. 


True 


False 
20. 
GPS reference stations for accurate vertical adjustment should include at least __________ NAVD first order benchmarks. 


Two 


Three 


Four 
21. 
An error estimate of ______________ is commonly seen as the minimum baseline error produced from static type surveys. 


10 mm 


20 mm 


30 mm 
22. 
Relative geoidal height precision from geoid modeling can have an expected standard deviation of_____________. 


1020 mm 


1030 mm 


2030 mm 
23. 
In areas with obstructions, dense vegetation, or high relief between monuments or projects site, GPS cannot exceed leveling accuracy when time is critical to the project. 


True 


False 
24. 
It was determined that higher accuracy elevations are obtained by the transfer of ellipsoidal height differences and relative geoidal heights from a station with a known NAVD88 elevation, than is possible from the direct application of absolute geoid heights to GPS networks. 


True 


False 
25. 
GPS relative positioning accuracy depends in part on the length of the measured baseline. 


True 


False 
