That fits with;
Battery A_roof 1A.
Battery F_ground
https://www.nytimes.com/1983/12/12/us/report-cites-antiaircraft-missiles-at-white-house.html
MISSILES AT WHITE HOUSE
UNITED PRESS INTERNATIONAL
DECEMBER 12, 1983
Ground-to-air missiles have been installed near the White House to guard against air attack, Time magazine reported in its latest issue.
Both the White House and the Pentagon declined comment on the report, which was released yesterday.
The magazine cited unnamed military sources as saying any such missiles at the White House would have to be shoulder-fired Stingers or Redeyes and would fall under the control of the Secret Service.
The missiles could easily be stationed on the roof of the White House, the sources said.
The magazine asserted that security officers control a cache of missiles from a command center in the Old Executive Office Building next to the White House.
I remember on 9/11 a whole bunch of stuff popped up & out ... and that was 18 years ago (whole bunch more now!)