Hello, I've turned up little in searching for a package that already has this function. Dspat is close but I don't think it does quite what I want. I have observation data gathered from a ship transect doing a zig-zag pattern. I have the current location of the ship, the ship's bearing, the angle from the transect to the sighting, and the observed distance to the sighting (and the height of the observer above water). Is there already a package/function in R that will "easily" convert this information to the lat/lon of the observed animal? Thanks for any help or guidance. Corrie --- Corrie Curtice Research Associate Marine Geospatial Ecology Lab Nicholas School of the Environment, Duke University http://mgel.env.duke.edu em: corrie.curtice at duke.edu
Calculate location given observation distance and angle from transect line
2 messages · Corrie Curtice, Robert J. Hijmans
Corrie: I think you can use the function 'destPoint' in 'geosphere', It computes (for longitude/latitude coordinate data) the coordinates of a destination point given a start point, initial bearing, and distance. Robert
On Wed, Feb 17, 2010 at 8:00 AM, Corrie Curtice <cc157 at duke.edu> wrote:
Hello, I've turned up little in searching for a package that already has this function. ?Dspat is close but I don't think it does quite what I want. I have observation data gathered from a ship transect doing a zig-zag pattern. ?I have the current location of the ship, the ship's bearing, the angle from the transect to the sighting, and the observed distance to the sighting (and the height of the observer above water). ?Is there already a package/function in R that will "easily" convert this information to the lat/lon of the observed animal? Thanks for any help or guidance. Corrie --- Corrie Curtice Research Associate Marine Geospatial Ecology Lab Nicholas School of the Environment, Duke University http://mgel.env.duke.edu em: corrie.curtice at duke.edu
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