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The Emissions and Dispersion Modeling System (EDMS) was developed in the mid-1980s as a complex source microcomputer model designed to assess the air quality impacts of proposed airport development projects.

What is EDMS Designed to Do?
The Emissions and Dispersion Modeling System (EDMS) is designed to:
Assess the air quality impacts of airport emission sources, particularly aviation sources, which consist of:

  • Aircraft
  • Auxiliary power units
  • Ground support equipment
  • Ground access vehicles
  • Stationary sources

EDMS is one of the few air quality assessment tools specifically engineered for the aviation community. It includes:

  • Emissions and dispersion calculations
  • The latest aircraft engine emission factors from the International Civil Aviation Organization (ICAO) Engine Exhaust Emissions Data Bank
  • Vehicle emission factors from the latest version of the Environmental Protection Agency's (EPA) MOBILE6 model
  • EPA-validated dispersion algorithms

An EPA “Preferred Guideline” Model Since 1993
Since 1993, EDMS was the EPA “Preferred Guideline” model for use in civil airports and military air bases.

FAA Required Model
In 1998, FAA revised its policy on air quality modeling procedures to identify EDMS as the Required Model (PDF) to perform air quality analyses for aviation sources instead of the preferred model. This revised policy ensures the consistency and quality of aviation analyses performed for FAA. The FAA continues to enhance the model under the guidance of its government/industry advisory board to more effectively determine emission levels and concentrations generated by typical airport emission sources.

EDMS 5.0.2 (June 2007)
EDMS 5.0.2 contains bug fixes and minor improvements over EDMS 5.0, and EDMS 5.0.1 and represents a significant improvement in capabilities and functionality over the EDMS 4.x series.  Here is a short list of the major improvements made in the EDMS 5.0 series:

Study & Overall Modeling Improvements

  • Over 220 new aircraft
  • Over 65 new engines
  • Multiple scenarios, multiple airports, and multiple years all in one study
  • Harmonized emissions inventories and dispersion analyses
  • New dynamic aircraft performance-based modeling
  • New sequencing modeling for taxi times
  • New capability to use hourly weather data in emission inventories
  • More precise aircraft delay and sequencing capabilities by operational profiles in 15-minute bins
  • Improved EDMS menu architecture
  • The Airport Emissions Reduction Credit (AERC) report is now integrated into EDMS
  • Taxiway usage is now computed automatically
  • Import and Export features are enhanced and available under the FILE menu
  • Runway queues are now computed dynamically by the sequencing model

Saving Study

  • Similar to other Windows applications, the EDMS 5.0 user must explicitly “save” the study to disk.  This will allow the user to revert to the last saved version, if an error is made during data entry.  However, updating the emissions inventory will automatically save the study data upon completion of the emission calculations.

Emissions Modeling

  • New dynamic emissions module computes aircraft LTO emissions based on performance parameters and weather conditions
  • New FOA3 methodology for estimating PM emissions from aircraft engines at non-US airports
  • New FOA3a methodology for estimating PM emissions from aircraft engines at US airports

Dispersion Modeling

  • Dispersion is now performed on all mass emissions up to the mixing height
  • Dispersion is conducted using the exact same values from the emissions inventory

Airports

  • Added fidelity where the physical airport layout can now be used for emissions inventory purposes as well as dispersion
  • Completely redesigned Airports Database with nearly 35,000 airports world-wide
  • New weather dialog allows the user to choose between annual average or hourly weather, set the mixing height, and launch the AERMET wizard
  • Dynamic weather feature when using hourly data directly affects aircraft performance, aircraft emissions, and the selection of the active airport configuration(s).  The airport configuration dynamically affects sequence modeling for taxi times and runway usage.
  • Streamlined taxiways consisting of multiple segments
  • New capability to designate taxipaths linking gates with runways
  • Runway ends can be assigned individual elevations as well as individual glide slopes
  • Improved runway configuration capabilities by either using hour of the day, ceiling, visibility and temperature as activation parameters to determine the appropriate configuration, or the user can specify the fixed percentage configurations to be used annually and EDMS5.0 will match the required percentages.

Aircraft

  • Improved fleet database is now common between EDMS and INM
  • New dynamic flight performance modeling harmonized with INM
  • Transition from takeoff to climbout is now dependent upon aircraft performance characteristics and weather
  • Aircraft schedules can be used in lieu of operational profiles
  • Boeing Fuel Flow Method 2 is used to scale emissions for a contiguous range of weather conditions, rather than just standard atmospheric conditions.
  • Engine startup emissions are now quantified and reported
  • Arrivals and departures have be separated for flexibility

Non-Aircraft Sources

  • MOBILE 6.2 is the only MOBILE model version available
  • Both ‘GSE assignment’ and ‘GSE population’ can be run in the same scenario
  • Emission factors for GSE have been updated according to EPA’s NONROAD 2005
  • A single roadway can now be composed of multiple segments
  • EDMS 5 no longer doubles roadway traffic to model round-trips

This release includes:

Instructions for upgrading from EDMS 5.0x to EDMS 5.0.2:

  • If you already have EDMS 5.0 or EDMS 5.0.1, download the update to EDMS 5.0.2 here 5.0.x-5.0.2 (ZIP), and download the documentation files above.
  • You do not need to apply for the BADA license again.
Instructions for ordering the EDMS 5.0.2 CD:

  1. Send the completed EDMS order form (PDF) to edms@cssiinc.com or call (202) 863-2175.
  2. Request a free license from EUROCONTROL

    EDMS 5 uses the EUROCONTROL Base of Aircraft Data ("BADA") for aircraft performance modeling. In addition to completing the EDMS Order Form, the user must also obtain a free license directly from EUROCONTROL for use of BADA by visiting the following website:
    http://www.eurocontrol.fr/bada/license

    Please follow these steps when completing the license agreement:

    1. Complete the Licensee portion of the agreement to the best of your ability.
      1. Legal form of company refers to how the company is registered (e.g. non-profit, LLC, etc.)
      2. The registered office of which is at: (indicate where the company is registered)
    2. Complete the Requestee official credentials section
      1. You are requesting BADA 3.6
    3. Complete the intended use of BADA section
      1. Select “other” and enter: Purchase EDMS Model
      2. You must complete all of the fields in red regarding the project that requires the use of EDMS.  Be sure to describe in detail the intended use of the software in more than just a few words.  You cannot use EDMS for a comparative analysis of aircraft types, and must clearly state that you will not do this.
      3. (You probably learned about BADA through the EDMS web site.)
      4. Under description of use, indicate that BADA will be exercised exclusively through the EDMS model to support airport emissions calculations
    4. Do not complete the optional section on the BADA calculation tool, it is not needed by EDMS.
      1. Do not enter a machine name or username
    5. Check the box to indicate that you have read and understand the terms of the agreement

    Please do NOT contact EUROCONTROL for the status of your order or BADA license.

  3. Timing of EDMS Shipping
    Upon submission of the BADA license request, EUROCONTROL will notify the FAA within two (2) working days that the request has been approved. Subsequently, CSSI Inc. will distribute the EDMS CD to the user without further notice via the delivery method selected by the user.

EDMS Technical Support Questions:
Technical support is available via phone, fax, and email:

Other EDMS questions should be directed to:

EDMS 5 Weather Data Information
EDMS 5 generates input files for the powerful next-generation dispersion model developed by EPA, AERMOD.  The AERMOD meteorological preprocessor, AERMET, requires a significant amount of weather data in order to accurately characterize the atmosphere.  Surface data for each hour is required to determine the current wind direction, wind speed, temperature and cloud cover.  In addition, twice-daily upper-air observations are required to properly determine the mixing height.

Ordering Weather Data
Weather data are available for a charge from the National Climatic Data Center (NCDC) and for free from the EPA Support Center for Regulatory Air Models (SCRAM) and WebMET.

Surface Data
AERMET supports the following surface weather data formats. NOTE that weather data downloaded from the NCDC website are NOT compatible with AERMOD, so the NCDC data from CD-ROM must be used instead.

  • TD-3280: Historical and recent data can be ordered from NCDC.
  • TD-3505: Historical and recent data can be ordered from NCDC.
  • CD-144: Current data are not available from NCDC.  However, users that already have CD-144 data can use it with the AERMET algorithms included in EDMS 4.3.
  • HUSWO: Historical and recent data can be ordered from NCDC.
  • SCRAM: Historical data are available from EPA at SCRAM. Choose "Met Data" then "Surface Data."  Data are also available from WebMET.
  • SAMSOM: Recent data can be ordered from NCDC.  Historical data are also available from WebMET.

Upper-Air Data
Currently, only the TD-6201 and FSL formats are supported for the required twice-daily upper-air soundings. 

  • TD-6201 data are available from NCDC or WebMET. 

One of these soundings must occur in the early morning hours.  Typically, these soundings occur at 00:00Z and 12:00Z, which does not provide a sounding at the necessary time for many users outside the United States.  If a sounding is not available for your location, the Lakes Environmental Upper Air Estimator may be appropriate. Specific guidance regarding the AERMET data requirements are provided in the AERMET User’s Guide.

Previous Releases
5.0.1 (January 2007)
5.0 (January 2007)
4.5 (June 2006)
4.4 (November 2005)
4.3 (August 2005)
4.21 (March 2005)
4.2 (September 2004)
4.12 (October 2003)
4.1GSE (October 2003)
4.11 (December 2002)
4.1 (October 2002)
4.0 (May 2001)
3.0 (1997)

Updated: 11:25 am ET July 2, 2007