x_first, y_first corners or centers?
Added by Natalia L almost 5 years ago
Hi,
I 'd like to ask if the coordinates of x_first, y_first in the grid description represent the corner of the lower left cell or the center?
gridtype = projection
gridsize = $GRDSIZE
xsize = $dx
ysize = $dy
xname = x
xlongname = "x coordinate of projection"
xunits = "m"
yname = y
ylongname = "y coordinate of projection"
yunits = "m"
xfirst = $ORIGX
xinc = $RESX
yfirst = $ORIGY
yinc = $RESY
grid_mapping = lambert_conformal_conic
grid_mapping_name = lambert_conformal_conic
longitude_of_central_meridian = $central_lon
false_easting = 0.
false_northing = 0.
latitude_of_projection_origin = $central_lat
standard_parallel = $standard_parallel_1 $standard_parallel_2
longitude_of_prime_meridian = 0.
semi_major_axis=6370000.
inverse_flattening = 0.
longitudeOfFirstGridPointInDegrees = $orig_lon
latitudeOfFirstGridPointInDegrees =$orig_lat
Replies (3)
RE: x_first, y_first corners or centers? - Added by Ralf Mueller almost 5 years ago
hi Natalia!
That's cell centers. corners would be called xbounds and ybounds
cheers
ralf
RE: x_first, y_first corners or centers? - Added by Natalia L almost 5 years ago
Hi Ralf,
I used the cell centres as you suggested but I get a shift in the outcome grid. I used also the centres cells for the definition of longitudeOfFirstGridPointInDegrees . Is this correct?
Thanks
Nat
RE: x_first, y_first corners or centers? - Added by Ralf Mueller almost 5 years ago
yes, sounds correct. you may post the resulting griddes file with all variables evaluated. this would allow some x-checking
cheers
ralf