Page Comparison

A Coordinate Reference Systems (CRS) is a coordinate-based scheme use to locate entities in geographical space. It is an essential aspect of spatial data.

...

Div

style	background-color: #F8F9F9; border: 1px solid #666; font-size: 12px; padding: 0.5rem 0.5rem;

#==================================================================================
# Study Area
#==================================================================================

# Define Spatial 'Extent' of Study Area: Mission Beach backdrop
# --------------------------------------------------------------
StudyArea.extent = extent(146.0333, 146.0833, -17.9333, -17.8583)

# Create a working spatial structure from the spatial 'Extent'
# ------------------------------------------------------------
# Create a 'Spatial Polygon' from Spatial 'Extent'
StudyArea.SP = as(StudyArea.extent, "SpatialPolygons")
StudyArea.SP # Has not CRS

Div

style	background-color: white; border: 1px solid #666; font-size: 12px; padding: 0.5rem 0.5rem;

## class       : SpatialPolygons 
## features    : 1 
## extent      : 146.0333, 146.0833, -17.9333, -17.8583  (xmin, xmax, ymin, ymax)
## coord. ref. : NA

...

Div

style	background-color: #F8F9F9; border: 1px solid #666; font-size: 12px; padding: 0.5rem 0.5rem;

# Add a CRS. Use: EPSG:4326 = 'WGS84' - General Spatial Reference (https://spatialreference.org/ref/epsg/wgs-84/).
proj4string(StudyArea.SP) = CRS("+init=epsg:4326") # Add CRS
StudyArea.SP # Has a EPSG:4326 CRS

Div

style	background-color: white; border: 1px solid #666; font-size: 12px; padding: 0.5rem 0.5rem;

## class       : SpatialPolygons 
## features    : 1 
## extent      : 146.0333, 146.0833, -17.9333, -17.8583  (xmin, xmax, ymin, ymax)
## coord. ref. : +init=epsg:4326 +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0

...

Div

style	background-color: #F8F9F9; border: 1px solid #666; font-size: 12px; padding: 0.5rem 0.5rem;

# Reproject Rasters to EPSG:4326 (general spatial CRS with coordinates on the WGS84
# datum on the Stamen Maps)
# -----------------------------------------------------------------------------------
# SPGC Study Area 2010 Winter
SPGC.StudyArea.2010q3.reprj.rl = projectRaster(SPGC.StudyArea.2010q3.rl, crs=CRS("+init=epsg:4326"))
# SPGC Study Area 20101Winter
SPGC.StudyArea.2011q3.reprj.rl = projectRaster(SPGC.StudyArea.2011q3.rl, crs=CRS("+init=epsg:4326"))
# SGGC Study Area 2010 Winter
SGGC.StudyArea.2010q3.reprj.rl = projectRaster(SGGC.StudyArea.2010q3.rl, crs=CRS("+init=epsg:4326"))
# SGGC Study Area 2011 Winter
SGGC.StudyArea.2011q3.reprj.rl = projectRaster(SGGC.StudyArea.2011q3.rl, crs=CRS("+init=epsg:4326"))
# SPGC Study Area Difference between Winters of 2011 and 2010
SPGC.StudyArea.Diffq3.reprj.rl = projectRaster(SPGC.StudyArea.Diffq3.rl, crs=CRS("+init=epsg:4326"))
# SGGC Study Area Difference between Winters of 2011 and 2010
SGGC.StudyArea.Diffq3.reprj.rl = projectRaster(SGGC.StudyArea.Diffq3.rl, crs=CRS("+init=epsg:4326"))

Versions Compared

Old Version 10

New Version 11

Key