terrel.inp

• NTDF – Change to ‘1’ if using GTOPO30 data (as we only have one input DEM file) or ‘4’ if using SRTM3 data
• OUTFIL – Change to e.g. ‘masaya.dat’. This is main output file that will contain the gridded processed terrain data.
• LSTFIL – Change to e.g. ‘masaya.lst’. This is essentially the log file.
• PLTFIL – Change to e.g. ‘masaya.grd’. This is an output file that can be plotted with e.g. the Surfer software package.
• RAWECHO – Change to e.g. ‘raw_masaya.dat’. This is an output file that simply echoes the raw input DEM data but in ASCII format.
• SAVEFIL – Change to e.g. ‘masaya.sav’. This is an output binary save file that can later be used for a continuation run of TERREL (we probably don’t need this).
• XYINP – (if LXY = T is set below) Change to ‘data/xy_masaya.dat’. This is the path to the input receptor points file.
• XYOUT – (if LXY = T is set below) Change to e.g. ‘xyoutput_masaya.rec’. This is output (elevation heights) at the receptor points.
• LCFILES – Set to T (true). This is a bit annoying, but all files have to have names in either full uppercase or lowercase, and I find lowercase nicer.
• Subgroup (0b) – At the end of this section, ensure that there are as many lines as input data files. If using GTOPO30 data, there should be one line that reads "1 !GTOPO30 = data/w100n40.dem ! !END!". If using SRTM3 data, there should be 4 lines that read "1 !SRTM3 = data/n11w086.bil ! !END!", "2 !SRTM3 = data/n11w087.bil ! !END!", etc
• LINTXY – Set to F (false). Receptor point elevations will not be interpolated but be be the peak heights.
• XYRADKM – Set to 5.0. Search radius (km) for locating the peak heights at the receptor points.
• LCOAST – Set to F. We don’t have coastline data to process.
• LBLNREAD – Set to F. We don’t have coastline data to process.
• LVOIDFIL – Set to F. Don’t interpolate to fill void cells. This should ensure the same behaviour as used by Sara.
• MSHEET – Set to 0 for now. This will ensure the same coordinate mapping as used by Sara. Consider switching back to 1 at a later date.
• IUTMZN – Set to 16. This is the UTM zone for Nicaragua.
• XREFKM – Set to 525.09417. This is the x-coordinate of the reference point (lower left corner) of the intended output grid. I think this is an easting (km) relative to the lower left corner of the UTM zone being used.
• YREFKM – Set to 1294.23926. This is the corresponding y-coordinate (northing).
• NX – For a 1km resolution, set to 91; for a 100m resolution, set to 901. This is the intended number of grid cells in x.
• NY – For a 1km resolution, set to 55; for a 100m resolution, set to 541. This is the intended number of grid cells in y.
• DGRIDKM – For a 1km resolution, set to 1.0; for a 100m resolution, set to 0.1. This is the intended grid spacing (in x and y) in km.