The first production model of the SPY-1 series is SPY-1, which forms the baseline configuration of all subsequent SPY-1 radars.

It was discovered that the false alarm rate was high because the radar would pick up swarms of insects and clutter from mountainous terrain.

About 10% of the software totaling thirty thousand lines were rewritten to accommodate the necessary upgrade.

[5]: 316–317  In 2003, the U.S. Navy donated a SPY-1A antenna to the National Severe Storms Laboratory in Norman, Oklahoma, making it one of the first stationary phased arrays used in weather forecasting.

SPY-1B adopts VLSI, resulting in increased performance and reduced size and weight.

There are 4,350 radiators with two side lobe cancellation antennae, each with two elements, and the radar uses eleven 16-bit microprocessors.

The ability to counter steep diving missiles was improved with more energy at higher elevations or longer pulse.

[6][7] SPY-1D(V), the Littoral Warfare Radar, was an upgrade introduced in 1998 with a new track initiation processor for high clutter near-coast operations, where the earlier "blue water" systems were especially weak.

SPY-1E utilizes commercial off-the-shelf (COTS) subsystems, and a single-faced demonstration unit was built in 2004.

[5]: 316–317  As of 2007, none were in service, although the radar is incorporated into the design of the yet-unbuilt AFCON Corvette [es].