2.0 LAS Directory Structure

2.1 Introduction
2.2 Top-level directories
2.3 Important lower-level directories
2.4 EDC directories not referenced at PSU
2.5 Record of PSU modifications

2.1 Introduction

The directory structure for release 7 of LAS has been modified from that used under previous releases. Directories containing source code have been separated from those actually used for LAS execution at the top level of the directory tree, with the latter being created from the former when LAS is built. An exception is the tae/ directory, which contains both executables and source.

The EROS Data Center (EDC) release of LAS 7.4 includes the AVHRR Data Acquisition and Processing System (ADAPS), which is not supported at PSU. Accordingly, the PSU version of LAS has moved ADAPS-related components of the EDC release to a new edc/ directory.

By convention, a given directory at any level normally contains either all directories or all files -- not a mixture of both. Exceptions to this include Build and Makefile files in directories which otherwise contain only directories.

2.2 Top-level Directories

The top-level directories needed for running LAS are

env/ Contains files which define the LAS run-time environment, including scripts to define environment variables needed by LAS, certain tables referenced by LAS applications, and log files used to record LAS usage.
run/ Contains all executables for LAS applications modules and some supporting "tools" modules. Also contains a copy of system documentation and HTML-format "help" files.
tae/ Contains the TAE exective, which provides the user interface to the LAS applications modules. Also contains source and other directories needed to rebuild the TAE exectutive.
The additional top-level directories needed to (re)build LAS are

src/las/ Contains sources for LAS applications modules, support functions, header files, and on-line documentation.
src/bin/ Contains sources for various "tool" routines which support LAS system management and setup.
build/ Created as part of LAS system build to contain binary support libraries and copies of LAS header files, which are then used when building the LAS applications.

2.3 Important Lower-level Directories

The contents of the principal directories needed to run and build the PSU version of LAS are briefly discribed below. When LAS starts up, it defines environment varibales pointing to may of these directories. The run-time directories are

env/las/assign/ C-shell scripts for establishing the LAS run-time environment.
env/las/logfiles/ Log files recording the names of the user and process each time a LAS process is run. Note: both the directory and the logfiles are world writable; this enables the logging funtion, logit(), to close the old logfile and create a new one whenever it reaches a predefined maximum size, currently 512 kbyte.
env/las/tables/ Tables needed by the geographic projection transformation routines; also tape and disk configuration files.
run/bin/ "Tool" routines needed to start up LAS, (re)build LAS modules from source, and facilitate system management. These are described in the "Software Maintenance" section.
run/las/base/ Baseline applications. These have been well tested and documented.
run/las/contrib/ Contributed applications (from sources other than PSU). These have not been as thoroughly tested and/or documented as the baseline applications.
run/las/ditto/ A set of tape file manipulation utilities.
run/las/doc/ The HTML documentation tree for LAS.
run/las/local/ Applications modules developed at PSU.
tae/bin/ Setup scripts and executable for the TAE executive.
tae/pdf/ TAE procs for initiating and terminating TAE/LAS processing.
The additional directories needed for building LAS include
build/las/include/ Header files needed for building LAS applications and support modules.
build/las/lib/ Object libraries for LAS support functions.
src/las/base/app/ Source-code directories for individual baseline applications.
src/las/base/ditto/ Source-code directories for the "ditto" tape file utilities.
src/las/base/doc/ Top levels of HTML documentation, copied to run/las/doc/ when LAS is (re)built. Note that documentation for individual application modules is created dynamically from the .pdf files when each module is built, and copied directly to run/las/doc/. Many of the .html files from this directory are overwritten by corresponding PSU-specific versions from src/las/local/doc/ .
src/las/base/include/ Standard LAS header files, copied to build/las/include/ when LAS is (re)built.
src/las/base/support/ Source-code directories for baseline support functions.
src/las/contrib/app/ Source-code directories for individual contributed applications.
src/las/contrib/support/ Source-code directories for contributed support functions.
src/las/env/assign/ Scripts which define the LAS environment; copied to env/las/assign/ when LAS is (re)built.
src/las/env/install/ Scripts for (re)building entire LAS system.
src/las/env/tables/ Geographic projection datum conversion tables and tape and disk configuration files; copied to env/las/tables/ when LAS is (re)built.
src/las/local/app/ Source-code directories for individual "local" (PSU-developed) applications.
src/las/local/doc/ PSU version of LAS and TAE documentation.
src/las/local/include/ Header files for support functions not included in EDC distribution. Note that some header files needed by LAS applications are under src/las/local/support/ , and are copied during system build into build/las/include/.
src/las/local/support/ Source-code directories for support functions not included in the EDC distribution; these include HDF and Geotiff libraries obtained directly from their maintainers.
las/local_edc/app/ Source-code directories for individual "local" applications developed at EDC. These have not been installed or carefully evaluated at PSU, but some of them may prove of interest to local users.
tae/include/ Header files defining the TAE interface functions used by LAS applicatations and the TAE executive.
tae/lib/ Libraries of TAE interface and support functions.
tae/src/ Source code for TAE executive and interface/support functions.

2.4 EDC Directories Not Referenced at PSU

The directories moved to the top_level edc/ directory for the PSU version of LAS are

edc/adaps/ Source code for the ADAPS package (not supported at PSU). This directory has a subdirectory structure similar to that of the las/ directory.
In addition, some individual directories not needed for the PSU version of LAS 7.4 have been renamed by appending "_edc" to their original names but have not been moved under the edc/ directory.

Similarly, individual files which are not referenced by the PSU version or have been superceded by modified versions also have "_edc" appended to their original names.

2.5 Record of PSU Modifications

As noted above, files or directories in the EDC distribution of LAS 7.4 which are not used at PSU are flagged by appending "_edc" to their original names. The same renaming convention is used to identify the original versions of files which have been modified at PSU. This does not apply to directories which have been moved to the edc/ directory.

Specific modifications to modules of the EDC distribution are recorded in a file named PSUmods for each directory. For each modification, this file contains the name of the file modified or moved, the date, and the nature of the modification and reason for it.

A consolidated list of PSU modifications is available in file run/las/doc/manager/psu_las72_mods.txt.

Last change: 2005 Feb. 21, R. A. White / raw@essc.psu.edu