Linda H. Graff and Daniel L. Visone
The Seamless Integration of Commercial-Off-The-Shelf (COTS)
and Government-
Off-The-Shelf (GOTS) Products to Meet the Army's Terrain Analysis
Requirements
ABSTRACT
This paper provides an overview of the integration of ArcInfo,
ERDAS Imagine, and Government-developed algorithms to meet the
terrain analysis requirements of the Digital Topographic Support
System/Quick Response Multicolor Printer (DTSS/QRMP). The system
requirements, the functional allocation of these requirements
to the selected COTS and GOTS software products, and the "lessons
learned" while attempting a "seamless" integration
will be presented.
The DTSS/QRMP is an automated battlefield system being developed to provide the U.S. Army's terrain teams with the automated capability to perform terrain analysis and prepare topographic products within the time frames required to support tactical combat operations.
To expedite the development and reduce development risk, the Combat
Terrain Information Systems (CTIS) at the U.S. Army Topographic
Engineering Center, Alexandria, Va., in conjunction with the Lockheed
Martin Corporation, Ft. Washington, Pa., is establishing the standard
for the integration of COTS and GOTS hardware and software into
the tactical environment. By leveraging the strengths of the
selected COTS and GOTS software packages, the end result is a
faster, less expensive upgrade of the Army's everyday operations
using state-of-the-art technology.
Introduction
Army terrain teams are required to provide battlefield commanders
with up-to-date terrain analysis and topographic products to support
tactical combat operations. Currently, these functions are performed
manually and require both highly skilled analysts as well as many
hours of preparation. Project Director, Combat Terrain Information
Systems (PD, CTIS), the materiel developer of all automated terrain
analysis systems for the Army, is developing the Digital Topographic
Support System/Quick Response Multicolor Printer (DTSS/QRMP) and
the DTSS-Multispectral Imagery Processor (DTSS-MSIP) at the U.S.
Army Topographic Engineering Center, Alexandria, VA. The prime
contractor for these systems is Lockheed Martin Corporation (LMC),
Fort Washington, PA. These systems use state-of-the-art Commercial-Off-The-Shelf
(COTS), Government-Off-The-Shelf (GOTS) and custom-developed software
to provide terrain teams with automated and semi-automated tools
to perform the required analysis in a timely manner.
System Requirements
Army terrain teams are frequently required to produce a wide range
of products, including thematic overlays, intelligence overlays,
image maps, 3-D perspective views, and text reports. In addition
to product generation, the analyst must also be able to update
existing vector data using current source material. All of these
tactical decision aids (TDAs) must be capable of being output
in hard copy format and being sent electronically in digital form
across the battlefield to other DoD systems. Because of the wide
range of system requirements, it was determined that the most
effective approach was to integrate a geographic information system
(GIS) to handle the vector data, an image processing software
package to handle the raster data, and specialized Government-developed
software to meet additional requirements. In addition to the
COTS and GOTS software, the current system also uses custom-developed
C, X/Motif, Ada, and Unix Shell Scripts.
The two COTS products selected for use are ArcInfo and ERDAS
Imagine. In general, the COTS products were chosen because they
are complimentary, have some overlapping functionality, have some
degree of interoperability, and are widely used in the marketplace.
The great value of using existing COTS products that are market
leaders is that the cost of developing functionality and maintaining
that functionality is much less than that of custom-developed
products because the cost for developing the functionality is
amortized over the marketplace. ArcInfo is a market leader for
vector analysis and data manipulation by GIS users and ERDAS is
a market leader for image exploitation, both packages have significant
functionality that overlaps. The software requirements were allocated
to the COTS products based on the maturity and ability of their
respective data analysis functions and user interface capabilities
to support specific functional requirements.
COTS/GOTS Functional Allocation
In order to provide a "seamless" integration of the
COTS and GOTS products, all menus and interfaces are designed
to have the "look and feel" of ERDAS Imagine. This
is due largely to the fact that most of the system users are already
familiar with ERDAS Imagine, and it was much easier to change
the menu fonts and colors in ArcInfo to look like Imagine menus
than vice versa. The integration of the two COTS packages was
made easier by existing industry efforts to couple the two software
packages. By selecting from the strengths of both packages, the
overall DTSS/QRMP functionality is greatly enhanced.
The main graphical user interface was developed using C and X/Motif.
ArcInfo's Arc Macro Language (AML) and ERDAS Macro Language
(EML) menus form the majority of the lower-level user interfaces.
In general, ERDAS Imagine provides a much more mature user and
data interface, which can be controlled and accessed from C language
code using the ERDAS C toolkit.
Input into the system includes various types of vector and raster
data sets. Vector data is handled by ArcInfo in the form of
coverages and grids. Vector data used by the current system is
limited to Defense Mapping Agency (DMA) ITD. ITD currently comes
in two formats -- Standard Linear Format (SLF) and Vector Product
Format (VPF). ArcInfo SLF ITD coverages are formatted with relate
tables and the VPF ITD coverages consist of regions and routes,
neither format is handled by ERDAS Imagine. ITD consists of six
feature layers: slope, vegetation, surface drainage, obstacles,
soils, and transportation. Each ITD layer covers a single 1:50,000-scale
DMA topographic map sheet. These layers provide the building
block for all of the ArcInfo functions in the DTSS/QRMP. Future
releases of the system will permit the use of DMA's Digital Chart
of the World (DCW), Tactical Terrain Data (TTD), as well as numerous
other vector data sets.
Raster data is processed primarily by the ERDAS Imagine software
package. The most commonly used raster data include Landsat TM;
SPOT Panchromatic and MS; and ARC Digitized Raster Graphics (ADRG);
however the software is also capable of ingesting many different
types of data including Interferometric Synthetic Radar (IFSAR)
and NITF-formatted data. DMA Digital Terrain Elevation Data (DTED)
Level 1 (approx. 90 m) and Level II (approx. 30 m) data are also
required to support many of the system functions.
Specific DTSS/QRMP functions include: 1) Project Manager, 2)
Environmental Models, 3) Intervisibility Models, 4) Mobility Analysis,
5) Special Purpose Products, 6) Source Data Editor, 7) Terrain
Visualization, and 8) Final Product Review (FPR). These functions
are in addition to the standard image processing capabilities
provided by ERDAS Imagine. The system also must meet contract
requirements for data base management, to include data lineage
tracking. Each of these functions will be discussed in turn:
Project Manager
Project Manager enables the user to organize a physical disk working
area where data and created products are stored. The project
manager function is provided via the custom-generated C code using
the ERDAS C toolkit.
Environmental Models
Environmental models use GOTS software to access various historical
climatic data bases covering different environmental statistics.
These models include the ability to obtain text output related
to the Sunrise/Sunset/Twilight and Moonrise/Moonset/Illumination
for any given date and location.
Intervisibility Models
Intervisibility models use line-of-sight algorithms to compute masked area plots, flight line masks, and oblique projections. Neither ArcInfo or ERDAS Imagine provide native capabilities to meet the military requirements of this function. Imagine provides no resident capabilities and even though ArcInfo has functions to compute visible area plots, these functions do not consider curvature of the earth or radio line-of-site refraction effects, both military requirements. The Terrain Integrated Rough Earth Model (TIREM) GOTS software package developed by the Electromagnetic Compatibility Analysis Center (ECAC) is currently under consideration to meet this requirement.
Mobility Analysis
Mobility analysis provides for the production of vehicle movement
products as well as textual bridge classification output. The
mobility products implement the NATO Reference Mobility Model
II (NRMMII) and other algorithms to evaluate terrain factors,
weather conditions, and various military vehicle parameters in
order to generate TDAs. GOTS software was developed by the U.S.
Army Waterways Experimentation System (WES) to implement these
algorithms and develop the associated required vehicle parameters.
The GOTS software interfaces with ArcInfo in order to analytically
process the input vector data.
Special Purpose Products
The special purpose product functionality includes "Data
Query" and "Product Stacker." Because ArcInfo's
vector processing functions are superior to those provided by
Imagine, it was selected as the COTS package to create the special
purpose products, which heavily rely on vector data input. Data
query enables the user to define categories by selecting the appropriate
attributes of features that meet particular military scenarios.
Generated queries include such things as the best place to land
helicopters or where to find construction resources for engineering
purposes. The user can also perform a "Proximity Analysis"
or buffer operation while in data query. The Product Stacker
function enables the user to arrange the display order and symbology
of a single product or multiple products. Future software releases
will also include the capability to produce slope, slope aspect,
contour, and shaded elevation tint products. An additional function
called "Smart Stacker" will also allow the user to
build new products from existing products rather than directly
from the vector data.
Source Data Editor
The source data editor provides the user with the capability to
generate new vector data layers, update existing vector data with
new information obtained from recent image acquisition, and modify
vector layers as required. These data can be used to update digital
map products, as well as serve as vector layer input into mobility
and special product generation. ArcInfo was selected for the
source data editor because the Imagine vector module is not capable
of manipulating vector data to the extent that is possible in
ArcInfo. Imagine cannot currently handle complex data like ITD.
Terrain Visualization
The current terrain visualization capability uses ERDAS Imagine to create static 3-D perspective views from user-defined viewer and target locations. The Perspective View function was implemented in ERDAS Imagine rather than ArcInfo because the user interface for Imagine's Perspective View is mature and easy to use and required no additional software development. The draping of imagery over the 3-D surface occurs much faster in Imagine, especially if the image either covers a large area and/or is high resolution. The DTSS/QRMP will use the ERDAS Virtual GIS package when it becomes available on the HP and Sun platforms for fly-thru/drive-thru capabilities.
Final Product Review
Both ArcInfo and ERDAS Imagine were extensively evaluated for
implementation of the final product review function. The evaluation
revealed a limitation in ArcInfo's ability to process imagery.
Since typical output products would consist of vector TDA's overlaid
on top of imagery, this was seen as a significant limitation.
The selection of Imagine for Final Product Review (FPR) was made
for several reasons: 1) the users are already familiar with Imagine's
map composer capability; 2) the interface is easy to use, i.e.,
easily scalable and annotation is very easy to use; and 3) vector
overlays can be displayed using translucent colors. This is very
important for displaying filled polygons over imagery.
The ERDAS C Toolkit was used to develop custom software to import
the symbol and map layout information for the mobility and special
purpose products created in ArcInfo into the ERDAS Imagine Map
Composer module used for FPR. Final product review provides the
user with a structured method to create map layouts and output
hard copy map products. The output can be single or multiple
vector products, in many cases overlayed on top of a raster map
or image background.
Data Base Management
Several different packages have been evaluated to meet the system's
data base management requirements, which include accessing data
and products graphically or through metadata. Products selected
for evaluation include: 1) Image Catalog, 2) MCS Softcopy Catalogue,
and 4) GeoCatalogue.
Image Catalog is provided as part of the ERDAS Imagine software
package. However, it only supports the ERDAS ".img"
file format. Image Catalog also currently provides no SQL connectivity
as required by the DTSS/QRMP program.
Map Cataloging System (MCS) Softcopy Catalog is based on software
developed by LMC for DMA. This software, along with the IS2000
data base access functionality (an internal research and development
project), is still a viable candidate. Because LMC has access
to all of the source code, this option provides the most flexibility.
The MCS Softcopy Catalogue would also provide the user with the
ability to determine which supporting DMA products covered their
area of interest.
GeoCatalogue by Vision International may be the strongest candidate
because it provides connectivity with ERDAS Imagine and has SQL
support. It also provides an interface to access custom data
formats and data types such as VPF, Raster Product Format (RPF)
and CGM.
The DTSS/QRMP has very stringent data lineage/tracking requirements
down to the feature level to ensure that all end-users maintain
a common picture of the battlefield. In order to meet these lineage/tracking
requirements, three approaches have been evaluated to date: 1)
ArcStorm, 2) Geolineus, and 3) custom-developed AMLs. ArcInfo's
ArcStorm currently provides more functionality than needed and
would have to be customized. Geolineus by Geographic Designs,
Inc. only tracks changes at the coverage level and does not meet
the system requirements at this stage of development. Further
studies in AML customization and third-party product evaluation
are ongoing.
Software Integration Limitations
Several limitations were identified in the process of attempting
a "seamless" integration of ArcInfo, ERDAS Imagine,
and GOTS software. Because COTS packages use X-window resources
differently, menus and windows seem to pop-up all over the screen
in no discernable pattern. This is very distracting to the user.
It also makes the process flow more difficult to follow in a
complex function like data query, which requires numerous menu
inputs in a logical sequence.
In order to use the products created by the mobility and special
purpose models in FPR, the ArcInfo symbols must be translated
into similar Imagine symbols. However, fonts and symbology for
vector data are not portable between ArcInfo and ERDAS Imagine.
Custom-developed software was generated to map the shade, line
and point symbology, and colors between ArcInfo and ERDAS Imagine.
The C toolkit functions needed to do this were not documented
and an ERDAS consultant was hired to assist in this effort.
Neither COTS products supports standard military symbology and
the symbol storage mechanisms for the two products are natively
incompatible. The line styles that ERDAS Imagine's vector functionality
can support are very limited. But Imagine's Map Composer has
strong annotation capabilities and a relatively mature user interface.
However, unlike ArcInfo, which allows for complex symbols that
are comprised of multiple layers, Imagine provides only a limited
simple symbol set. Many symbols that are available to the user
in ArcInfo are not available in the DTSS/QRMP FPR implementation.
Imagine was selected to provide the system's perspective view
capabilities because of the easy to use user interface and the
rapid display of imagery within the perspective view module.
However, unlike ArcInfo, which allows the user to easily drape
vectors layers over a 3-D surface, Imagine does not provide this
capability without creating a new image that has the vectors as
part of the image.
Military and DMA data formats are not commonly available as export
data types for COTS products. For example, ADRG, CADRG, and E-map,
which are raster formats used by the Army's Common Operating Environment
GIS TEM (Terrain Evaluation Model), are not commonly generated
as output from commercial GIS packages. This deficiency requires
more effort to integrate custom written software or other external
libraries.
Interfacing to the COTS products via standard high level languages
C and Ada are immature, complex and not well supported, thus requiring
a substantial learning curve.
Conclusions
The DTSS/QRMP provides custom-designed menus and tools created
to provide a user- friendly interface that enables the terrain
team analyst to tap into the strengths of each software package.
Tactical decision aids that once took many hours of manual preparation
can now be produced in a matter of minutes. Even though the use
of COTS and GOTS to meet the DTSS/QRMP terrain analysis requirements
was not a "plug and play" integration effort, these
packages provided a tremendous building foundation and required
minimal customization as opposed to a totally customized development.
As the COTS software developers continue to tightly couple their
software packages, development of complex systems like the DTSS/QRMP
will be made even easier in the future.
Linda H. Graff and Daniel L. Visone
U.S. Army Topographic Engineering Center
7701 Telegraph Rd.
Alexandria, VA 22315-3864
Telephone: (703) 428-8165
FAX: (703) 428-6302
graff@tec.army.mil
dvisone@tec.army.mil