Hi,
I'm trying to create a 20x20m fishnet grid to define quadrats for field data surveys. The maps I am using are in British National Grid and projected into Geographical Co-ordinate system WGS 1984 (this is because I want to use the maps in conjunction with a GPS unit that only works in lat/long). Creating fishnets works in the same spatial units as the dataframe. I want to draw 20x20m grids in a lat/long dataframe. I have tried converting the 20m measurements into degrees (according to geographical location - roughly 51deg N) but the grids do not appear to be a) square or b) of uniform size when plotted in a slightly (100m away) different location.
Any ideas?
Thanks,
Helen
I'm trying to create a 20x20m fishnet grid to define quadrats for field data surveys. The maps I am using are in British National Grid and projected into Geographical Co-ordinate system WGS 1984 (this is because I want to use the maps in conjunction with a GPS unit that only works in lat/long). Creating fishnets works in the same spatial units as the dataframe. I want to draw 20x20m grids in a lat/long dataframe. I have tried converting the 20m measurements into degrees (according to geographical location - roughly 51deg N) but the grids do not appear to be a) square or b) of uniform size when plotted in a slightly (100m away) different location.
Any ideas?
Thanks,
Helen