Karl's IPW experience

DEM in albers into IPW

The result is an image with four headers. The upper left corner is referred to as line 0, sample 0.

1) converted SierraBB-500m.tif to ASCII using ArcGIS Conversion Tools > From Raster > Raster to ASCII

2) stripped header with Wordpad

3) text2ipw -l 1450 -s 876 -b 1 -n 16 snbb500m.txt > dem.ipw

4) mkgeoh -c albers -u meters -o 389271.181648,-218640.76643 -d -500,500 dem.ipw > dem.geo.ipw

!<header> basic_image_i -1 $Revision: 1.11 $ byteorder = 0123 nlines = 1450 nsamps = 876 nbands = 1

!<header> basic_image 0 $Revision: 1.11 $ bytes = 2 bits = 16 history = text2ipw -l 1450 -s 876 -b 1 -n 16 snbb500m.txt

!<header> lq 0 $Revision: 1.6 $ map = 0 -10.99219036 map = 65535 4254.503906

!<header> geo 0 $Revision: 1.7 $ bline = 389271.181648 bsamp = -218640.76643 dline = -500 dsamp = 500 units = meters coord_sys_ID = albers

DEM in WGS84 into IPW

1) converted SierraBB-500m_wgs84 ASCII using ArcGIS Conversion Tools > From Raster > Raster to ASCII

2) stripped header with Textpad

3) replaced -9999 (no data) with 0 so that lq header would only go from dem min to max

3) text2ipw -l 1261 -s 1008 -b 1 -n 16 sierrabb-500m_wgs84.txt > demwgs84.ipw

4) mkgeoh -c 'geo' -u degrees -o -41.5206376,-122.615503 -d -0.0051981894,0.0051981894 demwgs84.ipw > demwgs84.geo.ipw

view factor for DEM spanning more than 1 degree

gviewf demwgs84.geo.ipw > demwgs84.gviewf.ipw

demux -b 0 demsfa2.gviewf.ipw > vf.ipw

demux -b 1 demsfa2.gviewf.ipw > ct.ipw

ipw2pbm vf.ipw > vf.pbm

ipw2pbm ct.ipw > ct.pbm

view factor for 90m SRTM DEM spanning more than 1 degree

mkgeoh -c geo -u degrees -o 41.520910931,-122.615503265 -d -0.00083333333,0.00083333333 snbb_90m_wgs84.ipw > snbb_90m_wgs84.geo.ipw