Apollo Strategic Growth Capital (APSG) 10-Q 2008 Q2 Quarterly report

Applied Signal Technology, Inc.
Exhibit 32.1

Certification of Chief Executive Officer Pursuant to
18 U.S.C. Section 1350,
As Adopted Pursuant to
Section 906 of the Sarbanes-Oxley Act of 2002

In connection with the Report of Applied Signal Technology, Inc. (the Company) on Form 10-Q for the period ended May 2, 2008 as filed with the Securities and Exchange Commission on the date hereof (the Report), I, William B. Van Vleet III, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

1. The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and result of operations of the Company.

/s/ William B. Van Vleet III - ---------------------------------------------	Date: June 9, 2008 - -------------------------------
William B. Van Vleet III Acting President and Chief Executive Officer