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Issue Date
2003-01-01Keywords
lasersterrain
global positioning systems
computer software
costs and returns
geographic information systems
models
topography
altitude
digital elevation model
DEM
digital terrain model
DTM
geographic information systems
GIS
global position system
GPS
topography
Metadata
Show full item recordCitation
Louhaichi, M., Borman, M. M., Johnson, A. L., & Johnson, D. E. (2003). Creating low-cost high-resolution digital elevation models. Journal of Range Management, 56(1), 92-96.Publisher
Society for Range ManagementJournal
Journal of Range ManagementAdditional Links
https://rangelands.org/Abstract
Ecologists and agronomists are interested in topography because it affects soil, plant, and hydrologic processes. Digital elevation models (DEMs) accurate to several centimeters of vertical elevation are needed but construction is time consuming and expensive when traditional surveying methods are used. Carrier-phase differential global positioning systems can map vertical changes in topography with root mean square errors (RMSE) of 2 to 9 cm, but equipment is expensive (20,000 to 100,000). Coarse-acquisition code differential global positioning systems (C/A code-DGPS) are much cheaper ( 8,000) and widely available but vertical errors are large with root mean square errors of 100 to 200 cm, which severely limits their usefulness in ecological studies. We combined a coarse-acquisition code differential global positioning system and a laser level (1,000) to map topographic change in fields, wetlands, and research plots. Our technique uses the coarse-acquisition code differential global positioning system for longitudinal and latitudinal (X or easting, Y or northing) position while the laser level provides vertical position (elevation) as measured from a ground control point or monument. Measuring elevation across a field scale area is a 2-step procedure. At each sample location the distance from the laser level to the ground is determined and entered as a comment in the differential global positioning systems data logger. In the office, sample locations are differentially corrected and elevation is calculated by subtracting the laser level-to-ground distance from the elevation of the laser. Data is then imported to geographic information system (GIS) software that interpolates between points. The differential global positioning system yields X, Y locations with a root mean square error of between 0.5 and 1.0 m. Elevations measured with our laser level had anaccuracy of better than 2 cm across its 230 m working radius. Our technique works best for areas up to approximately 40 ha on open, rolling terrain.Type
textArticle
Language
enISSN
0022-409Xae974a485f413a2113503eed53cd6c53
10.2307/4003887