A real ossim preferences file example:

Note there is a template file located at:
​http://trac.osgeo.org/ossim/browser/trunk/ossim/etc/templates/ossim_preferences_template

This is an example of an ossim preference file.

Note that it has unix style paths. On windows you should use windows paths.
e.g.: elevation_source1.filename: D:\elevation\srtm\1arc


Note also that you can name the file anything you want. OSSIM finds the file via the environment variable OSSIM_PREFS_FILE which should point to the name of your file. Alternatively you can use the "-P" option in any ossim application and point to the preference file.
e.g.: ossim-info -P ~/ossim_preferences --plugins

OSSIM Preference File Example

// ------------------------------------------------------------------------
// $Id ossim_preferences_template 14810 2009-06-30 20:33:21Z $
// 
// Description:  ossim_preferences_template
// 
// This file will be automatically loaded by ossim applications provided the
// environment variable "OSSIM_PREFS_FILE" is set to point to some form of 
// this file.
//
// Note:  c++ comments "//" can be used to comment a line.
//
// To set the environment variable for automatic preference file loading:
//
// This assumes a preference file in your home called "ossim_preferences".
// Typically this would be put in a dot file read at startup of a shell.
//
// tcsh and csh users:  setenv OSSIM_PREFS_FILE ~/ossim_preferences
//
// bash and sh users:   export OSSIM_PREFS_FILE=~/ossim_preferences
// 
// windoze users:       I'll have to look this up...
//
// You can also use the "-P <preference_file>" option at application startup.
// where <preference_file> is full path and filename.
// 
// ------------------------------------------------------------------------


// ---
// Elevation cell support:
//
// NOTE: Put you highest (best) resolution data first.
// 
// Keyword pair: 
// elevation_source.type
// elevation_source.filename 
// 
// Indicates an elevation source.  These should be listed in pairs.  Numbering
// should start with 1 with lowest number being the highest resolution.  This
// can be a cell(file) or a directory.
// 
// There are four elevation_source.type types:
// elevation_source.type: dted_cell
// elevation_source.type: srtm_cell
// elevation_source.type: dted_directory
// elevation_source.type: srtm_directory
// elevation_source.type: general_raster_directory
// 
// The elevation_source.filename keyword should point to a cell or a directory.
// 
// NOTES:
// The elevation_source keyword replaces the deprecated keywords:
// dted_directory
// srtm_directory
// dted_cell
// ---

elevation_source1.filename: /data/image_formats/elevation/srtm/1arc
elevation_source1.type: srtm_directory

elevation_source2.filename: /data/image_formats/elevation/dted/level2
elevation_source2.type: dted_directory

elevation_source3.filename: /data/image_formats/elevation/srtm/3arc
elevation_source3.type: srtm_directory

elevation_source4.filename: /data/image_formats/elevation/dted/level1
elevation_source4.type: dted_directory


default_elevation_path: /data/image_formats/elevation/srtm/1arc

autoload_dted_elevation:  true
elevation.enabled:  true
elevation.auto_sort.enabled:  true
elevation.auto_load_dted.enabled:  true

statusLatLon: true
statusHeight: true
statusDatum: true
statusGSD: true
statusUpdateOnClick: true

// ---
// Geoid support:
// Note:  Since the sensor models do earth intersects at height above the 
//        ellipsoid and the vertical datum of DTED is geoid_egm_96_grid, you
//        should have a geoid grid in place for accurate earth intersections.
// ---

// ---
// GEOID 99:  Set keyword to the directory containing the GEOID 99 grids.
// 
// Notes:  
// - Grids must be in the native byte order.
// - Can be downloaded from:
// http://www.ngs.noaa.gov/GEOID/GEOID99
// ---
geoid_99_directory:  /data/image_formats/elevation/geoid99_little_endian

// ---
// GEOID EGM 96:  Set keyword to the path to the egm96.grd
// 
// Notes:
// - Grid must be in BIG ENDIAN (UNIX) format.
// - Can be downloaded from:
// http://earth-info.nima.mil/GandG/wgs84/gravitymod/egm96/ww15mgh.grd.z
// ---
geoid_egm_96_grid: /data/image_formats/elevation/geoid96_big_endian/egm96.grd
// ---

// ---
// For state plane projection factory.
// --- 
state_plane_csv_file1: /work/drb/ossim/share/ossim/state_plane.csv
state_plane_csv_file2: /work/drb/ossim/share/ossim/harn_state_plane_epsg.csv

// ---
// plugin support:
// ---
plugin.file1: /work/drb/ossim_plugins/lib/libossimpng_plugin.so
plugin.file2: /work/drb/ossim_plugins/lib/libossimKakaduPlugin.so
plugin.file3: /work/drb/ossim_plugins/lib/libossim_plugin.so
plugin.file4: /work/drb/ossim_plugins/lib/libossimOpenJpeg_plugin.so
plugin.file5: /work/drb/ossim_plugins/lib/libossimreg_plugin.so
plugin.file6: /work/drb/ossim_plugins/lib/libossimgdal_plugin.so	

// ---
// The cache size is in megabytes
// ---
// cache_size: 256
// cache_size: 512
// cache_size: 1024
cache_size: 2048

// ---
// Keyword: overview_stop_dimension
//
// Affects any overview building from img2rr, imagelinker, iview.
// 
// This is the point where "img2rr" or the overview builded will stop 
// decimating the image down.  So in other words, if the 
// overview_stop_dimension keyword is 64, img2rr application will build 
// overviews, decimating each level by 2 until both the width and heigh are 
// less than or equal to 64.  Note the larger the dimension the less levels
// created.
// 
// Uncomment one below.
// ---
// overview_stop_dimension: 32
overview_stop_dimension: 64
// overview_stop_dimension: 128
// overview_stop_dimension: 256
// overview_stop_dimension: 512

// ---
// Keyword: tile_size
//
// Tile size x y
//
// Affects all ossim application.  This is the internal tile size of any
// image chain unless overridden by the filter.
// 
// Notes: 
// 1) OSSIM can handle any tile size; however it is best to use a size that
// is a power of two.
// 2) 
// 
// Uncomment one below.  
// ---
// tile_size: 32 32
// tile_size: 64 64
// tile_size: 128 128
tile_size: 256 256
// tile_size: 512 512
// tile_size: 1024 1024

// font.file1: /usr/share/fonts/default/Type1/b018032l.pfb
font.dir1: /usr/share/fonts/default/Type1

// ---
// Shape file pen color:
// Three values for red, green and blue between 0 and 1.0 with 1.0 being 
// brightness and 0.0 being black.
// ---
shapefile_normalized_rgb_pen_color: 1.0 0.004 0.004

// ---
// Shape file pen color:
// Three values for red, green and blue between 0 and 1.0 with 1.0 being 
// brightness and 0.0 being black.
// ---
shapefile_normalized_rgb_brush_color: 0.004 1.0 0.004
      
// ---
// Position Quality Evaluator (PQE) keywords. 
// Note Circulay Error(CE) and Linear Error (LE)  units are in meters.
// These keywords are for the imagelinker->image-window->PQE dialog box.
// They allow the user to calculater position quality factoring in backdrop
// and elevation uncertainty.
// ---

// Backdrop enter "name,ce90,le90" like "JOG-A,77,38".
pqe_backdrop1: TLM50,31,25
pqe_backdrop2: TLM100,61,25
pqe_backdrop3: JOG-A,77,38
pqe_backdrop4: TPC,613,47
pqe_backdrop5: ONC,1226,93
pqe_backdrop6: JNC,2452,187
pqe_backdrop7: GNC,6129,465

// Elevation enter "name,ce90,le90" like "SRTM_1ARC,20,16"
// Accuracies vary widely depending on terrain and how they were computed.
// These are just examples.
pqe_elev1: SRTM_3ARC,20,16
pqe_elev2: SRTM_1ARC,20,10
pqe_elev3: DTED_LEVEL2,40,20
pqe_elev4: DTED_LEVEL1,50,30
pqe_elev5: RPC_No_DEM_State,-2,-1.6449
// Special Case
// RPC_No_DEM_State, Scale Divisor, 1-Sigma Divisor (minus signs required)

pqe_normalized_rgb_ellipse_color: 0.004 1.0 0.004

// End of PQE keywords...