1. An unmanned aerial vehicle (UAV) radar apparatus, comprising: an RF front end module comprising an antenna and configured to transmit and receive RF signals; a filtering module coupled with the RF front end module that filters RF signals received at the RF front end module, the filtering module comprising: an analog-to-digital converter (ADC), wherein a sample rate of the ADC is variable, an on-board processor comprising: an ADC driver and block former module configured to generate data packets of variable sizes, an FIR frequency filter bank module configured to eliminate variable noise, a Fast Fourier Transform module or Discrete Cosine Transform module configured to generate frequency domain information, and frequency filter bank module configured to filter the frequency domain information; and a target data processing module coupled with the filtering module configured to detect one or more targets based on the filtered RF signals and identify the one or more detected targets based on signatures present in the filtered RF signals, wherein the UAV radar apparatus is small enough to be mounted on a UAV having a maximum vehicle takeoff weight of less than 20 kilograms, and wherein each of the RF front end module, filtering module, and processing module are interchangeable components, and each of the RF front end module and the filtering module are dispersible over the UAV.