Skip to main content

Direct Field Acoustic Testing (DFAT)

Options for Standards Update Notification System (SUNS)
Send SUNS Updates
SUNS Notification Type
Organization that Developed the Standard
Organization that Developed the Standard
NASA Standard
Document Identifiers
Document Number
Change Number
Document Date
Is Active?
NASA Organization and Technical Discipline
Responsible NASA Organization
NASA HQ, Office, Facility or Division
NASA HQ Office, Facility or Division
OCE - Office of the Chief Engineer
Technical Discipline Category
7000 - System and Subsystem Test, Analysis, Modeling, Evaluation
Endorsed Standard
Endorsement Details
Endorsing NASA Organization
OCE Endorsed Standard
NASA Core Standard
NASA Endorsement Date
NASA Endorsed Standard Status
NASA Endorsed Standard
Mandatory Standard
NASA Mandatory Standard
Not a NASA Mandatory Standard
Document Scope
Document Scope
The information in this handbook presents an overview of Direct Field Acoustic Testing (DFAT). DFAT is a relatively new aerospace acoustic testing method, first used for acoustic qualification of a spacecraft in the late 1990s. DFAT has certain advantages over the conventional reverberant field acoustic testing (RFAT) approach, in particular, reduced facilities development and maintenance costs and portability of the acoustic test equipment. The major disadvantages are a lack of coherent acoustic field that results in spatial variation; and the current technology limitation of not being able to produce sound pressure level (SPL) in excess of 147 dB. Even with the advancement of the control systems using DFAT for acoustic qualification testing, the pressure field and measured structural responses can differ significantly from an RFAT test, even if the control microphones are kept within the test tolerances specified. Significant advances in the DFAT control systems have been made in the last few years, which alleviate many of the previous concerns with this test method. However, application of DFAT varies widely among the NASA Centers and their contractors. Therefore, this NASA Technical Handbook provides the best current guidelines for implementation of the DFAT test method.
aerospace acoustic testing method, direct field acoustic testing, DFAT, RFAT, reverberant field acoustic testing
Document Access Control
Document Viewable by
Export Control/Distribution Authorization
Internet Public -- Standard is cleared for public accessibility on the internet.
PUBLIC: Upload Publicly Available Standard
Important Standard Dates
Next 5-Year Review Date
Submitting User
System Admin
Submitting User's Email

Last modified by:  Fred McMullen
Last modified on:  Sun, 10/15/2023 - 00:45


Application Notes for this Standard

-No Application Notes are associated with this standard.

Lessons Learned Related to this Standard

To associate Lessons Learned to a specific standard, find the related lesson in LLIS. These lessons have been vetted and approved via the lessons learned process. Then, click “Create a new “Lessons Learned” record for this Standard” and complete the information.

If you have a lesson learned that is not in LLIS, click “Proceed to the NASA Engineering Network to create a new “Lesson Learned” about this Standard” to be vetted and approved in that process. Then, associate the lesson by clicking “Create a new “Lessons Learned” record for this Standard.”

-No Lessons Learned are associated with this standard.