Synthetic Environment (SE) Core Database Development Process
PEO STRI, PM CONSIM
PEO STRI, PM CONSIM
PEO STRI, PM CONSIM
PEO STRI, PM CONSIM
PEO STRI, PM CONSIM
ABSTRACT: The SE Core is part of the United States Army's overarching strategy of developing
simulation systems that help make our Warfighters the best trained in the world. The two primary
initiatives under the SE Core program are the Architecture and Integration (A&I) and the Database Virtual
Environment Development (DVED). The A&I is not the focus of this presentation and will not be discussed.
The SE Core's primary mission is to rapidly generate correlated simulation system terrain databases. The
master SE Core database is populated from a union of multiple authoritative data sources by using a suite
of commercial and government-off-the-shelf database tools. The SE Core DVED architecture and tools will
enable the generation of SE Core runtime terrain databases in days or weeks vice months or years.
The focus of this presentation is to describe the SE Core DVED production process. Key areas that will be
discussed will include the overall process and then focusing on the details to include: the initial database
request process; how source data for the requested database is gathered and prepared for use; the
refinement and enhancement of the source data; the standardization process; and the verification and
quality measures employed before delivery. Additionally, the authors will present the current production
along with the various formats and map projections that are supported. The presentation will end with
exemplars of future efforts that SE Core DVED will be pursing in the future.
1. Introduction last three decades the price-performance benefits
of computer technology and the demand for
reconfigurable, less expensive, and more realistic
The acquisition of simulation training databases representations have driven simulation systems
has been a very complex, lengthy, and costly towards real-time digital computing and fully
endeavor. SE Core’s effort is developing synthesized environments.
processes and tools to create non-proprietary,
open format, image generator (IG) independent
Until the early 1980's, simulators were mostly
Environmental Representation (ER) databases1.
stand-alone systems designed for a specific task
training purpose. Until the introduction of the
The SE Core Master Database (MDB) is the
SIMNET program, no one had ever used a
central repository for the creation of correlated
multitude of simulators in a combined forces
databases used to train, mission plan, or mission
training environment, interacting over a network
rehearsal in the Live, Virtual, or Constructive
in real-time. SIMNET technology allowed
(LVC) domains. Within the DVED the database
crewmembers in one simulator, to interact with
architecture is coupled with a suite of COTS
many other manned or unmanned simulators
tools that enable database development.
located at the same or other training sites.
The SE Core effort will also develop common
virtual vehicle models, common virtual sensor Environmental Representation databases are
simulation software, and the virtual simulation comprised of many parts. Those parts include
component of the dynamic environment. The but are not limited to the terrain surface, terrain
dynamic environment will include approximate features, 3-dimensional models, textures, images,
visual effects from simulation (e.g., munitions, and other data such as system specific data to
mobility, engineering, rubbled buildings, etc.)2. satisfy computational requirements and labels for
producing electronic and paper maps.
The SE Core process is flexible, data-driven, and
extensible. The Standard/Rapid Database There are several constraints on the creation of
Generation Capability (STDGC) is designed to environmental databases. Perhaps the most
standardize, align, and clean source data in the prominent of these is dictated by the real-time
Master Terrain Database Generation Toolkit computation requirements. Since processing
(MTDGT), which also is used to generate power is often limited, once a computing
synthetic environment data using the Runtime platform is chosen for a given cost-performance
Database Generation Toolset (RDGT). Data is range, the software must be designed for best
exported in various formats from a standard real-time performance. This means both the data
application programmer interface (API)3. and the data structures stored in a platform-
Furthermore, the SE Core process addresses specific version (runtime) of an environmental
other challenges such as miscorrelation between database play an important role in optimizing the
simulations and lower database generation costs. system performance. Given the fixed
computational budget of a system, the database
In this paper we will first provide some designer must take into account the application-
background on the terrain database generation specific requirements, the size and extents of the
process. Next, we will present the SE Core database, the desired density and fidelity, as well
methodology to include how a database is as the type and amount of the available raw data
requested, the procedure for gathering source elements that must be incorporated into the
data, the standards that are used by SE Core, and database.
the techniques used to refine and enhance the
data. We will end with a discussion of the There are other application-specific requirements
verification and quality process used by SE Core. that must be taken into account such as those
related to whether the database will be used for
air, ground, sea, near ground, or any combination
2. Background4 of these simulations. The detail needed by a
simulator that allows an individual to walk on
Military training simulation systems have been the terrain is much greater than that expected for
around for decades. Most of these systems have a helicopter simulator typically flying several
used some derivation of the real environment to hundred feet in the air. Database density, size
represent the three-dimensional reality. In the
and extents, viewing range, field of view, and condition for achieving it. Since the variables
other important simulation requirements dictate affecting interoperability are many and complex,
the amount and type of data that can be included effective mechanisms for making the database
in a database without overwhelming the interchange process successful become
performance requirements. significantly more difficult and challenging.
Often the intended simulation platform imposes A critical factor in constructing and sharing
specific constraints. The specific special purpose environmental data is incorporation and use of
hardware architectures, designed for the sole good tools. Most tools are special purpose, given
purpose of real-time image generation, impose the various criteria and techniques employed by
vastly different constraints on the database different suppliers for constructing and tailoring
contents. Two database designers building a databases. As the domain of networked
database of the same region for two different IGs simulation expands and other information
often arrive at entirely different end results. The technology sectors emerge, the need for more
polygon or object processing capacity of an IG common and yet more sophisticated tools will
limits the database density to levels that can be increase.
processed in real-time. Similarly, image
rendering techniques drive whether a database Figure 1 is the SE Core processes with the
can contain textures and how many, or if the objective to be able to collect, generate, and
image generator can render all the objects that manage the Master Database (MDB) with the
are potentially viewable in a scene within a fixed highest fidelity of source data available. There
frame time. There are other architecture-specific are four major parts of the process. For this
features such as caching scheme, processing of paper the focus will be on how a database is
transparent objects, or image enhancement requested, the gathering of source data and its
techniques like anti-aliasing drive how a refinement. We will include a discussion of the
database may be partitioned. standards and quality measures that are used.
These types of computation
constraints are not unique to
visual systems. Any
Standard / Rapid Terrain Database Generation Capability
application that must achieve Supervisor
specific real-time performance Master Terrain Database Generation Run Time Database
measures has to reflect such Toolset (MTDGT) Generation Toolset (RDGT)
MDB Repository Quality
objectives in its design. This CGF
in turn impacts the data Write
Paper Map Plug-In PVD
Configuration Elec. Map Plug-In
structures, data types, and the Refinement
Source Data Quality
Source Data Inporter
information that is needed and
Run Time DBDD Plug-In
expected to be available from Master
a database. Storage Run Time
Raw Source Interchange Applications
Sources Formats Sources
Interoperability of multi- Source Data Asset Management
fidelity systems on the same
network is highly desirable; in
fact it is often demanded. The
challenge is in determining the "right" type and
amount of environmental data that each Figure 1: SE Core Process
simulator should use to ensure interoperability.
Most successful heterogeneous networked
exercises have been conducted under restricted 3. Database Request Process
The SE Core Database Request process is shown
A common misconception is to equate success in in Figure 2.
the interchange of data with success in
interoperability. Interchange of data does not
guarantee interoperability, but is one necessary
Figure 2: SE Core Database Request Process data is collected (discussed in the next section)
and any revisions to the request are processed
depending on the needs and availability of data.
If all is acceptable to the customer, the request is
passed to the database development team. The
current and future data formats available from
SE Core will be discussed in a later section.
The customer is provided with a database request
form. That form allows the customer to specify
the content they require. This includes but is not
limited to the features they require (e.g. bridges,
roads, agricultural areas), areas of significance to
include their location (e.g. specific buildings,
airfields), and the format of the database
transmittal. The customer can also use this form
to request any high resolution inserts that are of
importance to them.
4. Source Data
When a database request form has been
submitted and it has been approved, the process
of gathering source data begins (Figure 3).
Initially a program fills out a database request. If
the data already exists in the MDB and a means
to generate the required formats is available (e.g.
plug-ins) the request is forwarded directly to the START
production team and the desired data in the DATABASE
requested format is prepared and sent back to the
requesting program. DATA
DETERMINE DETERMINE COORDINATE
If the desired data is not already in the MDB, the TECHNICAL
STORAGE AND SOURCE DATA
ALLOCATION EXITING FACILITY
request is validated by the US Army TRADOC NO
Capabilities Manager (TCM) Virtual to include REVIEW
the size of the database region, the level of
fidelity required, and any other requirements of USEABLE
interest to the customer which have been SOURCE?
validated by TCM Virtual. YES
The database can be divided into separate zones VECTOR SOURCE
if the customer requires. Those zones range
from providing only the terrain skin for a reqion
in the database to high fidelity inserts of urban END
environments. Currently, there are five (5)
different zones available for the customer to
request and they include levels of fidelity of the
transportation network, population density to Figure 3: SE Core Source Data Collection
include buildings and building interiors, any Process
hydrography, significant military operational
features, and various vegetation that is required. There are five (5) questions that must be
answered as the database request is fulfilled.
Once the request has been validated, it is passed Those questions are:
to the program manager. At this point, source
1. What are the technical requirements information as the user that inserted the data into
(database and system)? the database, notes on why the data was
2. What are the resources required for populated, and the origin of the data. SE Core
acquisition? will be expanding the level and type of metadata
3. What are the storage/space in the coming year.
requirements for the data?
4. What coordination of acceptance of the The SE Core data model is based on the SEDRIS
source data must be done and how do ISO/IEC 18023-1 Data Representation Model
we deliver the resultant data? (DRM)8 and all data concepts are defined by the
5. Are there any conversions that are SEDRIS ISO/IEC 18025 Environmental Data
expected? Coding Specification (EDCS).9
The SE Core has also developed an extensive Along with the above standards, the SE Core
document that outlines the source data program is in compliance with the US NGA
investigated for use5. The reference document standards that are developed by ISO Technical
lists over 160 different types of data that are Committee (TC) 211.
currently investigated for use in building an SE
Core database. The principle data types that SE Regional information is stored as areal features
Core uses include: with the attribution that defines the region. For
example, a feature for a given area has the
1. Imagery: CIB, Buckeye, and attribution that defines possible textures that can
Quickbird be applied to models within the spatial extent of
2. Vector: VMAP, Urban Tactical that region. In addition, regions can be stacked
Planner, NAVTEQ, DAFIF, and Shape with a priority based on user needs.
3. Elevation: DTED, LIDAR There are several tools that are used to certify the
4. Models: Site Photos, Building data is ready for use. These tools check for
diagrams, CAD invalid and null geometry and attribution. Plus,
the tools check for compliance to the SE Core
Once the five questions have been answered and standards for geometry, spatial referencing,
the source data identified and collected, SE Core definition, labelling, etc. There will be a
is now ready to start processing of the data to complete section on the SE Core quality process
include refining and enhancement. However, and where in the SE Core process checks are
before this discussion is presented, a brief performed to make sure the user request has been
discussion of source data standardization will be met.
6. Data Refinement and Enhancement
A database, while required for a specified
All data is spatially partitioned based on MIL- purpose or training event in totality, oftentimes
PRF-89041A6. The imagery is stored based on contains certain areas in it that are more essential
the US NGA CIB format. For consistency, the than others for that particular use. Therefore, SE
vectors are also partitioned based on the CIB Core has developed a stratification of “zone” that
schema with one important difference; they are help both the user and SE Core to focus
not chopped to the tiles, but references the resources in those areas that are required by the
groups of features to the CIB tiles they intersect. customer to have greater attribution, while
All data is stored in latitude/longitude using the developing the full database.
WGS-84 reference datum. If source data uses a
different coordinate system or reference datum, There are five separate zones that are based on
the SEDRIS developed ISO/IEC 18026 – Spatial map projections (e.g. 1:250, 1:100). The zones
Reference Model7 is used for coordinate contain the level of fidelity that the map
conversion or datum transformation. projection would have, but in some cases there is
more information added based on the
Data element also have metadata attached. requirements that must be met. The additional
Currently, the metadata includes such information could be based on:
have the correct height, and the SE Core
A. SAF only padding automated tool checks are passed.
B. Ancillary areas 3. Elevation: Checks for elevation data
C. Navigationally significant areas include checking for spikes in the data,
D. Training areas making sure the proper projection is
E. High resolution Inset used along with the requested resolution
is present. Also, a check is made to
Also, within each of these zones/map projections make certain the data is correlated to the
there are different significant characteristics that ground truth.
are organized based on the user’s need. Below is 4. Models: The models are reviewed for
an example of five of those characteristics. polygon attribution, footprint, LoD,
lights, etc. Plus, there is a texture
1. Transportation review that includes the format, sizing,
2. Population and application.
4. Military Operations Once the data has been refined and enhanced, it
5. Vegetation is ready for the quality process checks.
Thus, if an area of the database is to be 7. Verification and Quality
developed at the Zone D level, the following
would be way the area is prepared for each of the
Figure 4 shows the SE Core quality steps
five characteristic areas:
(marked by letters “QC”). While there are steps
throughout the SE Core process, the majority of
1. Transportation: All transportation
steps are found in the Master Terrain Database
features extracted as linears. Parking
Generation Process. This is where source data is
lots extracted as areals.
taken in and a sequence of steps are executed to
2. Population: All buildings represented
guarantee the data is ready for uploading into the
with either 3D buildings or areal
SE Core MDB.
features that are extruded by the RDGT.
3. Hydrography: Hydro features validated
Each of the four principle source data types has a
against the imagery for location and
quality check. For instance, the vector data is
checked for duplicate features, self-intersecting
4. Military Operations: All features
features, feature overlap, and valid attribution.
extracted from imagery. Features not
For imagery, the data is checked for the
recognizable in overhead images will be
projection type and orthorectification. There are
placed by hand when appropriate source
elevation data checks for spikes and gaps and the
models are checked for conformance to the SE
5. Vegetation: Individual tree locations
Core model specification.
will be provided in the source data.
Forests will be extracted as areal
features. Trees will be scattered in the
RDGT. Standard / Rapid Terrain Database Generation Process
Master Terrain Database Generation Run Time Database
(MTDGT) Process Generation (RDGT) Process
As presented in the previous section, there are Sources Standardize QC Vector Digitizing DBRR
MDB Repository Quality
four fundamental data types that SE Core uses. QC
Vector Cleaning Assurance Pre-Validated
The following are the general processing that SE QC Textures QC DB
Core does for each of these data types. Elevation QC
QC QC QC QC
Imagery QC Database Project Set Up
1. Imagery: A check is performed for Raw Source Interchange CAD Architecture Technical Quarterly
Sources Formats Sources Interchange In
SME Working DB
Meetings Process Group Request
overall aesthetic quality to include Source Data Collection Database Request from TCM-V
colour and cloud cover. In addition the
resolution, projection, and correlation to Figure 4: Quality Checks Built into the
ground truth data are checked. Process
2. Vector: Checks include ensuring that
vectors are aligned with the imagery, At the runtime database generation step a series
attributions are consistent, buildings of tests are performed to validate the database
being generated for a user meets their Here is a brief list of tools that have been
requirements. Checks at this step include such created.
items as missing textures, terrain through
bridges, disconnected bridges, bad vertices, 1. AutoSnapper: Used to enhance
missing blocks, and specific tests for the various ArcMap snapping functionality.
formats that SE Core can produce (e.g. DTED, 2. MADV: Extends ArcMap and provides
Shape Files, OTF, CTDB, and STF). techniques to move, add, and delete
One such tool that SE Core has developed to 3. Google Earth Sync tool: Syncs the area
assist in this process is called the Vector of the world loaded within ArcMap to
Analyzer (VAZER). This tool was developed as Google Earth.
an extension to the ESRI ArcGIS and contains a 4. CM2 FID SMC tool: View and edit the
suite of tools that assist in finding issues with feature ID (FID) and Surface Material
vector data the production process. This tool can Code (SMC) setting of a moving model
find issues such as duplicate features, or in Multigen Creator.
improper attribution, or improper vector 5. The Attributor: Applies materials
alignment. attribution to a selected polygon based
on the data model specified.
8. Current Databases and Formats 6. EDM Editor: Used for editing the data
7. Validation Plug-in: Used with Terra
The SE Core program has produced several
Vista to validate data within the terrain
databases and supports over 15 different formats.
database specified by user inputs.
This phase of the effort has focused on the PEO
8. Illuminati: Calculates and stores default
STRI virtual programs Close Combat Tactical
intensity values or and average
Trainer (CCTT) and Aviation CATT
luminance of a group of polygons.
(AVCATT). As such, the primary databases that
9. Tune Town: Allows a user to tune
have been developed by SE Core have been
terrain database data.
those to support these programs. The databases
include Fort Hood, Fort Riley, Hawaii, Fort
Stewart, and several overseas databases. 9. Future Efforts
As stated above, the following list is some of the The SE Core program has been focused on
formats that are supported by SE Core: supporting the virtual domain. Now the program
will begin to add other domains. The first of
1. CADRG which is the constructive domain. In particular,
2. CCTT PVD SE Core will start the effort to provide OneSAF
3. CTDB with its required environmental representation
4. DTED databases.
5. Open Flight
6. OTF Also, with the addition of supporting
7. SEDRIS Transmittal Format constructive simulations, the type and amount of
8. VBS2 metadata required will increase. The SE Core
program will re-evaluate all of its current
SE Core DVED also supports these and other metadata types and add other data types to not
image generators: only support constructive, but live simulation
and training programs. As new required
1. EPX 50 metadata types are identified, they will be
2. Radon compared with ISO 19115-2, the currently used
3. SAGE metadata standard by the US NGA. If a new
4. S2 Focus metadata type is identified and it is not currently
in this standard, the SE Core program will
Along with the various databases, format, and approach ISO TC 211 and request that it be
image generators that SE Core supports, the added to the standard.
program has created over 60 tools that are used
to support these and other processes in DVED.
In addition to these efforts, the program has (3) Johnson M.D., J. Freeman, C.M. Perry;
several other required tasks that will be worked SE Core DVED – An Introduction to the
as resources are made available when existing Standard/Rapid Database Generation Capability
efforts are completed. (STDGC), July 2007 IMAGE Conference.
10. Summary (4) The Background Section was taken in
part from www.sedris.org.
This paper provided the current status of the SE
(5) SE Core SVR Management Program
Core program. We provided background on why
Attachment 19: Baseline Source Data Providers
the SE Core program is essential to the US Army
List, W900KK11R0002, October 2010,
simulation community and provided the top level
SE Core process. From there, we outlined the
database request process; how to get a database
form SE Core and then described the source data
and the process used to acquire source data. The
(6) US National Geospatial-Intelligence
principle data types used by SE Core are
Agency, MIL-PRF-89041A. Controlled Image
imagery, vector, elevation, and models (both
base. Bethesda, Maryland, USA: NIMA, 2000.
static and moving). Next, the SE Core
standardization process was discussed. The
(7) ISO/IEC 18026:2005, Information
process includes the use of several international
technology – Spatial Reference Model (SRM).
standards. A key area of discussion was how SE
Core refines and enhances the source data
(8) ISO/IEC 18023-1:2006, Information
collected. In particular, a discussion of how SE
technology – Data Representation Model
Core has defined five characteristic areas (or
zone) to enhance the level and fidelity of the
databases produced. By building a database
(9) ISO/IEC 18025:2005, Information
defined by these zones, enables the production
technology – Environmental Data Coding
process to focus on user required areas for high
definition/details and focus resources in those
areas. The verification and quality process was
outlined, too. There are over a dozen steps in the
SE Core process that have detailed quality
checks to make sure a database is developed and
delivered to a user correctly. The SE Core
database can be delivered in multiple formats
and can support multiple image generators.
Lastly, the future efforts were outlined. It is SE
Core’s intent to begin supporting constructive
simulation in the near future along with
reviewing the current metadata for possible
(1) SE Core Home page, Database-Virtual
Environment Development (DVED). Available
from World Wide Web: https://www.se-core.org/
(2) SE Core Program Begins helping Army
Warfighters train as they fight, Military
Simulation & Training News, Issue Number 19,
Fall 2008/Winter 2009, CAE. Available from
World Wide Web: