Hi Bill, If what your radar data files are like is what I imagine then ferret's curvilinear versions of contouring and vector plots should prove useful I imagine. Here is a demo, probably unrealistic in terms of the data file I've constructed to allow a lat-lon chart overlay - more a proof of concept. ! Step 1: Make a distance/angle netCDF file def axis/x=25:1025:50/units=km dist ! distance bins in 25km steps def axis/y/modulo/y=5:360:5/units=degrees angle ! angles in 5deg steps ! beginning 5deg north of east def grid/x=dist/y=angle gpolar let d2r=atan(1.)/45 ! degree to radian converter !define a test function ... let/title="Test Variable" v=cos(6*d2r*y[g=gpolar])/x[g=gpolar] ! ... and save it to a netcdf file save/file=radar.nc v ! Step 2: Read in the radar data and plot it ! cancel the variables so the radar "data" can be read in can var/all use radar.nc sho data ! currently SET data sets: ! 1> ./radar.nc (default) ! name title I J K L ! V Test Variable 1:21 1:72 ... ... !define cartesian coordinates ... let d2r=atan(1.)/45 ! degree to radian converter let/title="x(km)" xkm=x[g=v]*cos(d2r*y[g=v]) let/title="y(km)" ykm=x[g=v]*sin(d2r*y[g=v]) ! ... and contour [abs(v)]^0.25 (v itself drops off rather fast) fill/set abs(v)^0.25,xkm,ykm ppl axlen,6,6 ! set aspect ratio to 1:1 ppl fill ! create a gif of result - attached to this e-mail frame/file=radar-cartesian.gif ! now do it in lat/lon coordinates let x0=235 ; let y0=50 ; east-long & lat of radar location let/title="Latitude" ylat=y0+ykm/111.1 let/title="East Longitude" xlon=x0+xkm/(cos(d2r*ylat)*111.1) fill/set abs(v)^0.25,xlon,ylat ppl axlen,6,6 ; ppl fill ! cosine latitude noticable for this super-radar ! add the coastline from the etopo5 topography file use etopo5 region/x=220:250/y=41:60 contour/o/nolab/lev=(0.1) rose[d=2] ! and create another gif - also attached frame/file=radar-latlon.gif !------------------------------------------------- Hope this is of use, Mick PS If your netCDF files are structured far differently than mine, I suspect that with slightly modified algebra, it would still work. |!!! Mick.Spillane@noaa.gov !!!| |__Room 2070 Bldg#3 NOAA/PMEL__| |____Phone_:_(206)526-6780_____| On Fri, 16 Apr 2004, Bill Conway wrote: > I have been searching far and wide for a viewer, commercial or otherwise > that will display radar data (ie, polar radial data). Have had no luck. Does > anyone have any ideas?
Attachment:
radar-cartesian.gif
Description: radar-cartesian.gif
Attachment:
radar-latlon.gif
Description: radar-latlon.gif