Apollo Strategic Growth Capital (APSG) SC 13D APPLIED SIGNAL TECHNOLOGY / MMI INVESTMENTS ownership change

Exhibit 99.1

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1)(iii) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a Statement on Schedule 13D originally filed on October 22, 2010 (including amendments thereto) with respect to the Common Stock, no par value per share, of Applied Signal Technology, Inc.  This Joint Filing Agreement shall be filed as an Exhibit to such Statement.

Dated: October 22, 2010

MMI INVESTMENTS, L.P.
By:	MCM Capital Management, LLC General Partner
By:	/s/ Jerome J. Lande
	Jerome J. Lande
	Executive Vice President

MCM CAPITAL MANAGEMENT, LLC
By:	/s/ Jerome J. Lande
	Jerome J. Lande
	Executive Vice President

/s/ Clay B. Lifflander

Clay B. Lifflander