Contrary to claims made Multiple Input and Multiple Output (MIMO) radars do not provide an order of magnitude or better angle resolution, accuracy and identifiability (the ability to resolve and identify targets) over conventional radars. This claim is based on using a MIMO array radar system consisting of a full transmit array and thinned receive array (or vice versa; called here a full/thin array). This claim for MIMO results from making the wrong comparison to a full conventional array rather than to a conventional full/thin array. It is shown here that a conventional full/thin array radar can have the same angle accuracy, resolution and identifiability as a MIMO full/thin array. Where does the MIMO radar provide a better angle accuracy than a conventional radar? A monostatic MIMO array radar does provide a better angle accuracy than its conventional monostatic equivalent, but it is only about a factor of 1/√2 (29 percent) better and its resolution is the same.

A paradox of why there can be no pulsewidth distortion for an antenna array which is receiving or transmitting a wide-bandwidth chirp waveform is presented and explained. When a very narrow pulse is received at an off-boresite angle by an antenna array using phase steering, the pulse becomes distorted, that is, dispersed. The pulsewidth spreading is equal to the difference in the times of arrival of the pulse at the opposite ends of the antenna. However, if a wideband chirp waveform instead is incident on the antenna, no dispersion can be made to occur if the antenna is resteered toward the signal source during the time the chirp waveform is being received. The steering prevents frequency scanning of the antenna beam because of the changing carrier frequency of the linear FM chirp waveform. This represents a paradox because the dispersion still exists over the antenna. The author explains why the chirp signal is received undistorted at the output of the antenna in spite of the dispersion.>

Digital technology permeates electronic design, especially in the field of radar. This paper describes some ways in, which digital technology is used to overcome the limits of analog circuits, particularly in waveform generation, signal processing, and clutter suppression. Another example of the application of digital technology to radar is the general-purpose computer that is part of every modern radar. The ability of state-of-the-art computers to support radar requirements is surveyed, and future capabilities are projected.

Excellent reveiw papers on the state of the art of propagation through the atmosphere at laser wavelengths have been published during and prior to 1970. This concise paper gives a brief update of major developments that took place since 1970. Covered are the saturation phenomenon, heterodyne receiver performance, atmospheric turbulence model, and transmitter-aperture averaging effect.