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.: <some-ossim-application> -P ~/ossim_preferences <application-args>

OSSIM Preference File Example

// ------------------------------------------------------------------------
// $Id: ossim_preferences_template 14810 2009-06-30 20:33:21Z dburken $
// 
// 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.
// 
// ------------------------------------------------------------------------

// ---
// 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_manager.elevation_source.type: dted_directory
// elevation_manager.elevation_source.type: srtm_directory
// elevation_manager.elevation_source.type: general_raster_directory
// 
// The elevation_manager.elevation_source.connection_string is a connection for your database.  Typically this is a directory location.
// 
// NOTES:
// The elevation_source keyword replaces the deprecated keywords:
// dted_directory
// srtm_directory
// dted_cell
// 
//
// We support bringing cells into memory for dted and srtm datasets.  You can also control the number of open cells by
// specifying a min and max open cells.  If the number of cells opened exceeds the maximum then it will shrink the active
// opened cells to the minumum.  We currently use a least recently used algorithm.
// Examples:
//---
elevation_manager.elevation_source1.connection_string: $(OSSIM_DATA)/elevation/srtm/1arc
elevation_manager.elevation_source1.type: srtm_directory
elevation_manager.elevation_source1.min_open_cells: 25
elevation_manager.elevation_source1.max_open_cells: 50
elevation_manager.elevation_source1.memory_map_cells: false
elevation_manager.elevation_source1.geoid.type: geoid1996

elevation_manager.elevation_source2.connection_string: $(OSSIM_DATA)/elevation/dted/level2
elevation_manager.elevation_source2.type: dted_directory
elevation_manager.elevation_source2.min_open_cells: 25 
elevation_manager.elevation_source2.max_open_cells: 50 
elevation_manager.elevation_source2.memory_map_cells: false
elevation_manager.elevation_source2.geoid.type: geoid1996

elevation_manager.elevation_source3.connection_string: $(OSSIM_DATA)/elevation/srtm/3arc
elevation_manager.elevation_source3.type: srtm_directory
elevation_manager.elevation_source2.min_open_cells: 25 
elevation_manager.elevation_source2.max_open_cells: 50 
elevation_manager.elevation_source2.memory_map_cells: false
elevation_manager.elevation_source2.geoid.type: geoid1996

elevation_manager.elevation_source4.connection_string: $(OSSIM_DATA)/elevation/dted/level1
elevation_manager.elevation_source4.type: dted_directory
elevation_manager.elevation_source4.min_open_cells: 25 
elevation_manager.elevation_source4.max_open_cells: 50 
elevation_manager.elevation_source4.memory_map_cells: false
elevation_manager.elevation_source4.geoid.type: geoid1996

elevation_manager.elevation_source5.connection_string: $(OSSIM_DATA)/elevation/general_raster_1arc
elevation_manager.elevation_source5.type: general_raster_directory
elevation_manager.elevation_source5.min_open_cells: 25 
elevation_manager.elevation_source5.max_open_cells: 50 
elevation_manager.elevation_source5.memory_map_cells: false
elevation_manager.elevation_source5.geoid.type: geoid1996

// Identity geoid is 0 everywhere, so MSL = Ellipsoid. Useful when DEM provides posts 
// relative to ellipsoid instead of customary MSL. This is specific to each elev database:
//elevation_manager.elevation_source3.geoid.type: identity

// Default height above ellipsoid, for use when no elev data is present, instead of returning NAN:
//elevation_manager.default_height_above_ellipsoid: 0.0

// this is n elevation offset that is added to the height returned from the elevation manager.
// if the value is nan then nothing is added.
//
//elevation_manager.elevation_offset: nan

// Allows one to specify to the elevation manager to use the ellipsoid offset as defined by the geoid manager if a getHeightAboveEllipsoid fails
//
elevation_manager.use_geoid_if_null: true

default_elevation_path: $(OSSIM_DATA)/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:  $(OSSIM_DATA)/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: $(OSSIM_DATA)/elevation/geoid1996/egm96.grd
// ---

// ---
// Location of datum grids:
//
// Snip from: http://www.ngs.noaa.gov/TOOLS/Nadcon/Nadcon.html
// 
// Advances in the accuracies now obtainable in geodetic surveys, specifically
// through use of differential GPS, has allowed for the creation of state 
// High Precision Geodetic Networks (HPGNs), also referred to as High Accuracy
// Reference Networks (HARNs) throughout the country.
// ---
datum_grids: $(OSSIM_DATA)/elevation/nadcon

// ---
// For state plane projection factory.  Note do not add harn if you do not
// have the harn datum grids.
// --- 
epsg_database_file1: $(OSSIM_DEV_HOME)/ossim/share/ossim/ossim_epsg_projections-v7_4.csv
epsg_database_file2: $(OSSIM_DEV_HOME)/ossim/share/ossim/ossim_harn_state_plane_epsg.csv
epsg_database_file3: $(OSSIM_DEV_HOME)/ossim/share/ossim/ossim_state_plane_spcs.csv
epsg_database_file4: $(OSSIM_DEV_HOME)/ossim/share/ossim/ossim_wkt_pcs.csv
epsg_database_file5: $(OSSIM_DEV_HOME)/ossim/share/ossim/ossim_harn_state_plane_esri.csv

// ---
// deprecated for new geoid_ngs_directory keyword
//
// 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/ele1/geoid/geoid99

// current release only allows for a single directory
// we will allow for multiple directories later and auto detecting
// if possible.
//
// currently the file names are hard coded and need to be from the NGS distribution
// also downloadable from ftp.remotesensing.org under/ossim/test_data.tgz
//
geoid_ngs_directory: /data/ear1/geoid/geoid99
geoid_ngs_directory.byte_order: big_endian

// -- 

// ---
// Generic support has been added to each NGS geoid grid. You can download
// ngs grids for 1999, 2003, ... and should should work.
// byte order can be big_endian or little_endian
//geoid_ngs_directory1: /data/ear1/geoidngs99
//geoid_ngs_directory1.byte_order: 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 svn:
// svn co http://svn.osgeo.org/ossim/trunk/ossim_package_support/geoids geoids
// ---
geoid_egm_96_grid: /data/ele1/geoid/geoid96/egm96.grd


// ---
// Font support:
// NOTE:  To use the MapCompositionSource you must at least have "font.dir1"
//        set to some default.
// ---
// font.file1: /usr/share/fonts/default/Type1/b018032l.pfb
// font.dir1: /usr/share/fonts/default/Type1


//---
// OSSIM plugin support:
//
// Notes:  
// 
// Embedded trace debug can be turned on using "ossimDynamic" 
// eg using icp application: 
// $ icp -T ossimDynamic 
// ossimDynamicLibrary::load DEBUG:
// Loaded library:  /usr/local/lib/libossimpng_plugin.so
// ossimDynamicLibrary::load DEBUG:
// Loaded library:  /usr/local/lib/libossimgdal_plugin.so
// ossimDynamicLibrary::load DEBUG:
// Loaded library:  /usr/local/lib/libossimreg_plugin.so
// ossimDynamicLibrary::load DEBUG:
// Loaded library:  /usr/local/lib/libossimcontrib_plugin.so
//
// Keywords:
//
// plugin.dir1:  < directory where plugins are >
//
// you can also list by individual file names
//
// plugin.file1: < full path and file name >
//---
// Example, edit/uncomment as needed:
// plugin.file1: /usr/local/lib/libossimpng_plugin.so
// plugin.file2: /usr/local/lib/libossimgdal_plugin.so
// plugin.file3: /usr/local/lib/libossimreg_plugin.so
// plugin.file4: /usr/local/lib/libossimcontrib_plugin.so
// 
// END OSSIM plugin support
//---

// Toggles for recceVue application:
statusLatLon: true
statusHeight: true
statusDatum: true
statusGSD: true
statusUpdateOnClick: true


// ---
// Keyword: cache_size
// The cache size is in megabytes
// ---
cache_size:

// ---
// Keyword: overview_stop_dimension
//
// Affects any overview building from img2rr, imagelinker, iview. Controls
// the amount of resLevels created.
// 
// This is the point where "img2rr" or the overview builder 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


// ---
// Keyword: shapefile_colors_auto
// 
// Shape file colors set to automatic.
// This is a boolean value.  If true pen and brush color of shape files will
// be determined by indexing a color table in a round robin approach.  If set 
// to true the auto colors override keywords for "pen" and "brush" color.
// Default value if not found if "false".
// 
// Value can be: true, yes, y, 1, false, no, n or 0
// ---
shapefile_colors_auto: false

// ---
// 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: 0.004 1.0 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

// ---
// Shape file point size:
// Width and height for points in pixels.
// ---
shapefile_point_size: 6.0 6.0


// --------------------------
// Some keywords for the OSSIM GUI application
//
//
// igen spec files output./  This is the directory location you would
// like the igen export GUI to default to when outputing spec files
ossim.igen_spec_output_directory: /work/gpotts/igen_test

// this is the igen executable.  Make sure you put the full path
ossim.igen_executable:  /work/gpotts/ossim/bin/igen

// END keywords for OSSIM GUI
//--------------------------

//---------------------------------------
// osgPlanet Reference background setup

// Image type
//
//
ossimosgplanet.background.type: local

// each image listed with file0 ... file<n> 
//
ossimosgplanet.background.file0: C:\Program Files\Common Files\ossim\images\earth.tif
ossimosgplanet.background.transparent_color_flag:0
ossimosgplanet.background.transparent_color: 0 0 0
ossimosgplanet.background.opacity: 255

// END osgPlanet Reference Background
//---------------------------------------------

// ---
// 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...