Answer_Exercise3 - LSGI 3342 Geodetic Control Exercise...

Info icon This preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
LSGI 3342 Geodetic Control Exercise Three November 26, 2007 Name: Chong Wai Ming SID: 06701301D
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
1) Compare four different height systems (ellipsoidal, orthometric, normal, and dynamic heights) and establish relationships among the four systems. Only using conventional distance leveling measurement between any two equipotential surfaces may have distinct measurements at different location. It is far more accurate to measure the potential different along the plumb line instead, since the potential different is always the same between any two equipotential surfaces at any point. Heights are measurements based on the Geo-potential difference C, which is the potential difference ) ( 0 W W i - - between two equipotential surfaces. The reference point is infinite (W = 0) and Geoid 0 W can be used as a reference. Dynamic Height The dynamic height D i H is using Geopotential number i C is divided by a constant gravity R g , where R i D i g C H = On one equipotential surface, Dynamic heights are the same. However, the geometrical distances between equipotential surface and geoid are difference. Its’ unit is meter, but it is not the same as the meter in geometrical distance, since the potential is divided by R g , which is a scale factor. Dynamic height is unique and can be measured, and it is useful for water direction measurement. Orthomatric Height The Orthomatric height O i H is measured by the geometric distance between geoid and D P H P Equipotential surface at P Geoid
Image of page 2
along the plumb line of a point P, where _ g C H i O P = and _ g is the mean value of gravity from P0 to P along the plumb line. Orthomatric height also use meter as unit. The same orthometric heights have different potential value, since the mean gravity along different plumb lines are different. It is unique and can close loop from leveling. Normal Height Normal Height N i H measure the distance between the earth’s surface to the quasigeoid, along the plumb line of point P, and divided by the mean normal gravity _ i γ , where _ i i N i C H γ = ` Normal height is unique, and it also uses meter as unit. Since the mean normal gravity
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern