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Correct the GPS coordinates

Source: R/correctCoordGPS.R
correctCoordGPS.Rd

This function builds the most probable GPS coordinates of the plot corners from multiple GPS measurements.

Usage

correctCoordGPS(
  longlat = NULL,
  projCoord = NULL,
  coordRel,
  rangeX,
  rangeY,
  maxDist = 15,
  drawPlot = FALSE,
  rmOutliers = TRUE
)

Arguments

longlat

(optional) data frame with the coordinate in longitude latitude (eg. cbind(longitude, latitude)).

projCoord

(optional) data frame with the projected coordinate in X Y

coordRel

data frame with the relative coordinate in the same order than the longlat or projCoord

rangeX

a vector of length 2 giving the range for plot relative X coordinates

rangeY

a vector of length 2 giving the range for plot relative Y coordinates

maxDist

a numeric giving the maximum distance above which GPS measurements should be considered as outliers (by default 15 m)

drawPlot

a logical if you want to display a graphical representation

rmOutliers

a logical if you want to remove the outliers from coordinates calculation

Value

If there are no outliers or rmOutliers = TRUE, a list with:

  • cornerCoords: a data.frame with the coordinates of the corners

  • correctedCoord: a data.frame with the adjusted coordinates given as input

  • polygon: a spatial polygon

  • outliers: index of coordinates lines considered as outliers, if any

  • codeUTM: the UTM code of the coordinates if the parameter longlat is set

Details

GPS coordinates should be either given in longitude latitude (longlat) or in projected coordinates (projCoord)

Author

Arthur PERE, Maxime REJOU-MECHAIN

Examples

projCoord <- data.frame(
  X = c(
    runif(5, min = 9, max = 11), runif(5, min = 8, max = 12),
    runif(5, min = 80, max = 120), runif(5, min = 90, max = 110)
  ),
  Y = c(
    runif(5, min = 9, max = 11), runif(5, min = 80, max = 120),
    runif(5, min = 8, max = 12), runif(5, min = 90, max = 110)
  )
)
projCoord <- projCoord + 1000
coordRel <- data.frame(
  X = c(rep(0, 10), rep(100, 10)),
  Y = c(rep(c(rep(0, 5), rep(100, 5)), 2))
)

aa <- correctCoordGPS(
  projCoord = projCoord, coordRel = coordRel,
  rangeX = c(0, 100), rangeY = c(0, 100)
)
#> Warning: This function still work but will be removed (defunct) and replaced by checkCoordPlot in the next version. Please see VIGNETTENAME? vignette
#> Warning: longer object length is not a multiple of shorter object length
#> Warning: longer object length is not a multiple of shorter object length
bb <- correctCoordGPS(
  projCoord = projCoord, coordRel = coordRel,
  rangeX = c(0, 100), rangeY = c(0, 100), rmOutliers = TRUE
)
#> Warning: This function still work but will be removed (defunct) and replaced by checkCoordPlot in the next version. Please see VIGNETTENAME? vignette
#> Warning: longer object length is not a multiple of shorter object length
#> Warning: longer object length is not a multiple of shorter object length
#> Warning: calling par(new=TRUE) with no plot
# \donttest{
correctCoordGPS(
  projCoord = projCoord, coordRel = coordRel,
  rangeX = c(0, 100), rangeY = c(0, 100), drawPlot = TRUE
)
#> Warning: This function still work but will be removed (defunct) and replaced by checkCoordPlot in the next version. Please see VIGNETTENAME? vignette
#> Warning: longer object length is not a multiple of shorter object length
#> Warning: longer object length is not a multiple of shorter object length
#> $cornerCoords
#>          X        Y
#> 1 1008.039 1006.996
#> 2 1108.030 1005.645
#> 3 1109.381 1105.636
#> 4 1009.390 1106.987
#> 
#> $correctedCoord
#>           X        Y
#> 1  1008.039 1006.996
#> 2  1008.039 1006.996
#> 3  1008.039 1006.996
#> 4  1008.039 1006.996
#> 5  1008.039 1006.996
#> 6  1009.390 1106.987
#> 7  1009.390 1106.987
#> 8  1009.390 1106.987
#> 9  1009.390 1106.987
#> 10 1009.390 1106.987
#> 11 1108.030 1005.645
#> 12 1108.030 1005.645
#> 13 1108.030 1005.645
#> 14 1108.030 1005.645
#> 15 1108.030 1005.645
#> 16 1109.381 1105.636
#> 17 1109.381 1105.636
#> 18 1109.381 1105.636
#> 19 1109.381 1105.636
#> 20 1109.381 1105.636
#> 
#> $polygon
#> Geometry set for 1 feature 
#> Geometry type: POLYGON
#> Dimension:     XY
#> Bounding box:  xmin: 1008.039 ymin: 1005.645 xmax: 1109.381 ymax: 1106.987
#> CRS:           NA
#> POLYGON ((1008.039 1006.996, 1108.03 1005.645, ...
#> 
#> $outliers
#> [1]  7  8  9 13 15 17 20
#> 
# }