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Astrodynamic Standards Distibution Automation

Air Force Space Command

This site is the public interface used to initiate a request for Astrodynamic Standards Software.

The Astrodynamic Standards Software is a software suite of astrodynamic algorithms that are available to Air Force Space Command customers who require interoperability with the Joint Space Operations Center (JSpOC) and/or have requirements for astrodynamic standards capability needed for official work on active U.S. Government sponsored projects.

Due to the sensitive nature of these products, access to this software is tightly controlled. All applicants must be working on Astrodynamic-related programs in support of or in partnership with the U.S. Government. These products are not available for export or for commercial use.  

Why Should You Use AFSPC Astrodynamic Standards?

The Astrodynamic Standards were developed to ensure interoperability for users of the JSpOC satellite catalog. In order to obtain the most accurate prediction, users need to use the same propagator models that were used to generate the satellite catalog. The accuracy of an astrodynamic algorithm is primarily a function of its underlying physics model and the accuracy and compatibility of the data it uses. It is easy to understand that the "better" the underlying physics model or the more accurate the data, the more accurate the algorithm's calculation. However, it is not as intuitively obvious that the prediction model must also be compatible with those models generating the orbital data that it uses as input.

If the data products (either Two-Line Elements (TLEs) or Vector Covariance Messages (VCMs)) produced by the JSpOC orbit determination algorithms are used by a customer with a compatible propagator, they will make the "most accurate" prediction possible. However if the same JSpOC TLE or VCM is used by a customer with a non-compatible propagator, they will get a "less accurate" prediction.


Why use Astrodynamic Standards

Figure 1. Predictions with JSpOC vectors using WGS-72 versus WGS-84

Figure 1 gives an example of an actual operational incompatibility when predicting the location of a satellite. A user wanted to upgrade their WGS-72 geopotential model to the more accurate WGS-84. However, they were still receiving their data input in the form of WGS-72 produced vectors from the JSpOC. They had an accuracy requirement for DMSP satellites that a prediction would still be within one kilometer after three days, which they met with their old WGS-72 model (as shown in dark blue in the table above). However, if they had decided to upgrade to the incompatible, "but more accurate,"
tabASDA Software 
Please click here for a full list of Astrodynamic Standards software that can be requested. It includes a brief description of the software and information that allows you to discern which packages will fulfill your government project needs.

Additional help, resources, and reseach papers can be found at Astrodynamic Standards.

AFSPC/A9 has made considerable updates to the Astrodynamic Standards algorithms over the past year. The Astrodynamic Standard Library V7 is a major update to V5.4.2 and includes these new changes:
· The library has been modularized into many separate functional Dynamic Link Libraries (DLL), making it easier to learn and easier to integrate them into your application.
· The DLLs have been broken into 18 DLLs and contains approximately 360 DLL functions. Many functions in V5.4.2 that were hidden from the user have now been made available that will simplify your existing application code.
· The new design includes utility DLLs that can be utilized separately from the traditional Astrodynamic Standards algorithms.
- Time conversions (e.g. between various external formats, and from those formats to Days since 1950, Greenwich hour angle).
- Astrodynamic conversions (e.g. coordinate transformations, orbital element conversions).
- Satellite state (TLE, VCM, ephemeris) loading, creation, manipulation and output.
- Observations (e.g. conversion from transmission to internal format).
· The interface has been simplified to include only primitive data types.
· The changes made in V7 allow for the interface to be separated from the implementation which will enable upgrades/changes to the library transparent to users of the library.
· Many more programming languages besides C/C++ are now supported. Currently supported languages include: C/C++, C#, VB.Net, MATLAB, FORTRAN, Python, and Java (via JNA). In theory, any language that is capable of loading DLL's and calling functions from them can be used with the Astrodynamic Standard library.
· The DLLs have been designed to work easily with both non-Graphical User Interface (GUI) and GUI applications.
· The DLLs have been designed to better prepare for the future special requests.
· User documentation has been improved and expanded:
- Each DLL function is described including the passing parameters.
- Simple usage examples for implementing DLLs in multiple languages
To initiate a request for Astrodynamic Standards Software click here (select Astrodynamic Standards Request Form as the recipient) and send in all required information.
tabInstructions for requesting ASDA Software 
If you, your Quality Assurance Evaluator/Government Representative (QAE), your Contracting Officer's Technical Representative (COTR), or project management or mission area has access to the NIPRNet, it is highly recommended that you or they go to the Space / Cyberspace Analysis Resource Portal (SARP) at to enter the request there.
Making a request from here may take several weeks, whereas a request made via the SARP automatically generates the needed Request Letter and Non-Disclosure Agreement or Memorandum of Agreement. In addition, after approval of the request, the software can usually be downloaded from the SARP directly. Approval is based on who (organization) / what (project or specific mission) / and timeframe (the contract must be current for contractors).

To make an informed choice of the software that will support your work for the government, please review the List of Available Astrodynamic Standards Software.

Additional information on Astrodynamic Standards can be found here.

To initiate a request for software please click here (select Astrodynamic Standards Request Form as the recipient) and send in all required information. Incomplete requests may not be considered.

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