EAS221 Study Guide - Quiz Guide: Minute And Second Of Arc, Shuttle Radar Topography Mission, Bathymetry

• School: University of Alberta
• Department: Earth and Atmospheric Sciences
• Course: EAS221
• Professor: Alberto Reyes

Document Summary

Elevation data is useful in almost any gis application you can think of (any sort of land management, monitoring, planning, etc. ) Dsm digital elevation model digital terrain model digital surface model. Lidar: dem that portra(cid:455)s (cid:862)(cid:271)are-earth(cid:863) (cid:894)(cid:374)o vegetatio(cid:374) or (cid:271)uildi(cid:374)gs(cid:895) Non-overlapping triangles defined by lines that connect points of known elevation; irregularly spaced contour lines. Dem header files are very informative, including such details as radiometric resolution, number of rows a(cid:374)d (cid:272)olu(cid:373)(cid:374)s i(cid:374) a(cid:374) i(cid:373)age (cid:894)t(cid:455)pi(cid:272)al of a raster(cid:895), (cid:272)oordi(cid:374)ates of the upper left (cid:894)first(cid:895) (cid:272)ell, a(cid:374)d (cid:272)ell size, et(cid:272) . Tin is computationally simple because you only need to store the 3 points of each triangle. Tin is (cid:271)uilt usi(cid:374)g (cid:862)(cid:272)o(cid:374)ve(cid:454) hull(cid:863) for the outside the smallest polygon that encloses all points. Breakline: a linear feature with a known elevation; constrains the tin. Complexity of the model scales to the complexity of the terrain. Available data comes in a variety of formats so usually needs tweaking in gis.