An apparatus as described herein may include an antenna array that receives radio frequency signals and outputs analog signals. The apparatus may also include analog to digital signal converters that convert the analog signals into digital sample streams. Also, the apparatus may include a sample buffer that buffers subsets of the digital sample streams and a beamformer that uses the digital sample streams to generate one or more beam signals. Additionally, the apparatus may include a processor that determines a spatial characteristic or a spectral characteristic for the radio frequency signals based on the subsets of the digital sample streams.