2.8.3. updating Topography for CODAS

The installation instructions include a quick-download of previously extracted topography. If for some reason you want to know how we did that, or want to update it yourself, the instructions are below.

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A full Python CODAS installation requires topography that our python programs can read. You can use ETOPO or Smith-Sandwell topography this purpose, but you must follow instructions for download and installation (or UH Python code will not be able to read it). You must have compiled pycurrents (previous steps) before you can extract topography.

We use two topography products, ETOPO and Smith-Sandwell. You can get one or the other, or both. Etopo has the advantage of being global, and is probably adequate for many purposes.

Present versions we can parse are

1. ETOPO:

   • go to http://www.ngdc.noaa.gov/mgg/global/global.html

   • There are lots of versions, but the one we support is this ETOPO1 Ice Surface at this location

2. Smith Sandwell:

   • go to http://topex.ucsd.edu/WWW_html/mar_topo.html)

   • get Global Topography V18.1 at this location

The Etopo version keeps changing and you may have to edit the python code to get the right version number. Feel free to ask how to do this, or give it a try. You need to change the 18.1 above, and then recompile pycurrents

2.8.3.1. Installation:

1. • make a directory adjacent to the UH programs directory,

   • it must be called topog

   • inside topog make two directories

     etopo sstopo

   • ETOPO:

     • move the ETOPO file (etopo1_ice_g_i2.zip) into the etopo directory:

     • unzip there (etopo1_ice_g_i2.bin,etopo1_ice_g_i2.hdr)

   • Smith Sandwell:

     • move the Smith-Sandwell file (topo_18.1.img) to the sstopo directory

2. • in a shell window, with all environment variables set correctly, change directories to /home/adcpcode/programs/pycurrents/scripts (if the UH programs directory is /home/adcpcode/programs)

     run:

     python topo_sub.py

   • this should generate 2 more files for each type of topography. (it takes a long time). Then you should have:

(alongside these)

    programs/codas3/[etc]
    programs/pycurrents/[etc]
    programs/uhdas/[etc]
    programs/onship/[etc]

(new)

    topog/sstopo/topo_18.1.img
    topog/sstopo/topo_18.1s3.img
    topog/sstopo/topo_18.1s9.img

    topog/etopo/etopo1_ice_g_i2.bin
    topog/etopo/etopo1_ice_g_i2_s3.bin
    topog/etopo/etopo1_ice_g_i2_s9.bin

(3) The topog directory should be linked (or copied) to the location appropriate for your intallation style.