Generate a coordinate list for a regular rectangular survey

The coordinate list is generated in degrees decimal degree format (dd.ddd), with Southern hemisphere denoted by negative numbers. Transect length and inter-transect spacing are specified in km and bearings in degress where North 0 deg, East 90 deg, South 180 deg and West 270 deg.

Usage

lawnSurvey(
  startLon,
  startLat,
  lineLengthkm,
  lineSpacingkm,
  startBearingdeg,
  numOfLines
)

Arguments

startLon: start longitude of survey.
startLat: start latitude of survey.
lineLengthkm: transect line length in km.
lineSpacingkm: inter-transect spacing in km (see details).
startBearingdeg: Orientation of survey grid in degrees.
numOfLines: Number of transects.

Value

Data frame of geographical coordinates of start (SOL) and end of line (EOL) positions

Details

Line spacing can be fixed, so specified by a single number or pseudo random (random draws from a uniform distribution), which is specified by a vector of two numbers, the minimun and maximum transect separation.

Author

Martin Cox martin.cox@aad.gov.au

Examples

if (FALSE) {
(coords=lawnSurvey(startLon=-170,startLat=-60,lineLengthkm=2,lineSpacingkm=0.5,
startBearingdeg=30,numOfLines=5))
plot(0,0,xlim=range(coords[,1]),
ylim=range(coords[,2]),type='n',xlab='Longitude, deg',ylab='Latitude, deg')
arrows(x0=coords[1:(nrow(coords)-1),1], y0=coords[1:(nrow(coords)-1),2], 
      x1 = coords[2:nrow(coords),1], y1 = coords[2:nrow(coords),2])
text(coords,row.names(coords),cex=0.6)
points(coords[1,1],coords[1,2],col='blue',pch=17,cex=2)
points(coords[nrow(coords),1],coords[nrow(coords),2],col='blue',pch=15,cex=2)
legend('topright',c('Beginning','End'),col='blue',pch=c(17,15))
}