According to Phillip R. Hays, PhD LT USNR-R, the AN/SPS-30 referred to on the lighter's plaque was a shipboard air search radar that had the ability to
determine altitude of a target as well as bearing and range. This type of radar was often called a "3D" radar.
Such radar installations consisted of an antenna and pedestal, the transmitting and receiving equipment, and a control unit. The control unit was something like a radio tuner for your home entertainment system. It allowed the operator to adjust the operating characteristics of the radar set.
APL was most famously known for the development of the Proximity VT (Variable Time) Fuse, credited by military leaders as second in importance to the atomic bomb in ending WWII. APL management must have had a penchant for making souvenirs for their employees after they completed a contract. A souvenir VT fuse (it looks like a small missle) is owned by the Laurel Historical Society and Museum.
The vaguely art deco APL (shown here in a 1946 postcard) was razed sometime in the 1980s. If anyone knows the exact year, please let me know. For the past three decades the footprint of the structure has been used as a parking lot located next door to the Lee Building at the corner of Georgia Avenue and Colesville Road. This would have been a great building on Georgia Avenue's streetscape had it managed to survive, instead of the gapping hole we have long had to live with.
