An account of instrumentation radar development is given, and advantages and disadvantages of radar as compared to other instruments are discussed. Capabilities of present monopulse radars are described, based upon actual test data from the AN/FPS-16. This radar has a range of 200 miles on echo targets of one-square-meter cross section and can track to an accuracy of 0.1 mil in angle and 5 yards in range. The next generation in instrumentation radar is represented by the AN/FPQ-6, now under development, which will extend accurate tracking to ranges in excess of 500 miles on echo targets and will track existing beacons beyond the moon. An important capability not yet exploited in pulsed-instrumentation radars is the coherent pulsed-Doppler velocity-measurement channel which will equal the accuracy of microwave CW systems in radial-velocity data. Provisions for adding this fourth tracking channel to both AN/FPS-16 and AN/FPQ-6 are being made, and suitable beacons are being designed. An important advantage of pulsed-Doppler radar is the ability to share a single coherent beacon in multiple-station operation, providing highly accurate, three-coordinate velocity and position data without special interstation communication links over ground paths. Beyond the immediate developments of the AN/FPQ-6, there are three major areas of improvement which will greatly extend radar performance. Solid-state maser preamplifiers will increase sensitivity of microwave radars by a factor of nearly one hundred within one or two years. Microwave antennas are already under construction in the 100-and 300-ft diameter class.