An obstacle detection system comprising: an antenna layer comprising: a slotted waveguide radar transmit antenna; and a slotted waveguide radar receive antenna (122, 122A) at a separate location from the slotted waveguide radar transmit antenna on the antenna layer; radar transmitter electronics in signal communication with the slotted waveguide radar transmit antenna, wherein the radar transmitter electronics, in conjunction with the slotted waveguide radar transmit antenna, are configured to output FMCW radar signals, the radar transmit antenna providing a fixed transmit beam, radar receiver electronics (103, 350) in signal communication with the slotted waveguide radar receive antenna, wherein the radar receiver electronics includes digital beam forming circuitry configured to: receive from the radar receive antenna radar reflections corresponding to the outputted FMCW radar signals; and electronically form a monopulse receive beam (122A, 410B, 410C); one or more processors (214, 214A) configured to generate a notification of target detection information based on the radar reflections; and wherein the antenna layer, the radar transmitter electronics, the radar receiver electronics and the one or more processors are housed in a single, integrated package, wherein a single multi-layer circuit board comprises the antenna layer, the radar transmitter electronics, the radar receiver electronics and the one or more processors. an antenna layer comprising: a slotted waveguide radar transmit antenna; and a slotted waveguide radar receive antenna (122, 122A) at a separate location from the slotted waveguide radar transmit antenna on the antenna layer; radar transmitter electronics in signal communication with the slotted waveguide radar transmit antenna, wherein the radar transmitter electronics, in conjunction with the slotted waveguide radar transmit antenna, are configured to output FMCW radar signals, the radar transmit antenna providing a fixed transmit beam, radar receiver electronics (103, 350) in signal communication with the slotted waveguide radar receive antenna, wherein the radar receiver electronics includes digital beam forming circuitry configured to: receive from the radar receive antenna radar reflections corresponding to the outputted FMCW radar signals; and electronically form a monopulse receive beam (122A, 410B, 410C); a slotted waveguide radar transmit antenna; and a slotted waveguide radar receive antenna (122, 122A) at a separate location from the slotted waveguide radar transmit antenna on the antenna layer; radar transmitter electronics in signal communication with the slotted waveguide radar transmit antenna, wherein the radar transmitter electronics, in conjunction with the slotted waveguide radar transmit antenna, are configured to output FMCW radar signals, the radar transmit antenna providing a fixed transmit beam, radar receiver electronics (103, 350) in signal communication with the slotted waveguide radar receive antenna, wherein the radar receiver electronics includes digital beam forming circuitry configured to: receive from the radar receive antenna radar reflections corresponding to the outputted FMCW radar signals; and electronically form a monopulse receive beam (122A, 410B, 410C); receive from the radar receive antenna radar reflections corresponding to the outputted FMCW radar signals; and electronically form a monopulse receive beam (122A, 410B, 410C); one or more processors (214, 214A) configured to generate a notification of target detection information based on the radar reflections; and wherein the antenna layer, the radar transmitter electronics, the radar receiver electronics and the one or more processors are housed in a single, integrated package, wherein a single multi-layer circuit board comprises the antenna layer, the radar transmitter electronics, the radar receiver electronics and the one or more processors.