LANDSAT-4 and LANDSAT-5 Multispectral Scanner Coherent Noise Characterization and Removal

A technique is described for characterizing the coherent noise found in LANDSAT-4 and LANDSAT-5 MSS data and a companion technique for filtering out the coherent noise. The techniques are demonstrated on LANDSAT-4 and LANDSAT-5 MSS data sets, and explanations of the noise pattern are suggested in Appendix C. A cookbook procedure for characterizing and filtering the coherent noise using special NASA/Goddard IDIMS functions is included. Also presented are analysis results from the retrofitted LANDSAT-5 MSS sensor, which shows that the coherent noise has been substantially reduced

Clean Air, Clean Processes? The Struggle over Air Pollution Law in the People\u27s Republic of China

This Article commences in Part I by introducing law-making in China before reconstructing the drafting process and attendant political battles leading up to the revision of China\u27s principal air pollution law in 1995 – which, as Ackerman and Hassler observed with reference to the United States, can be every bit as messy as the soiled air such efforts are intended to address. Part II then examines the institutional factors that ultimately are critical to an understanding of why the 1995 APPCL, as promulgated, fell well short of its original authors\u27 objectives but set in motion a process that over time has led to the realization of at least some of these legislative goals through the 2000 APPCL. The Article concludes by suggesting the implications of these institutional considerations for environmental law and legislative development more generally in the PRC

Flight Investigation of a Normal-Acceleration Automatic Longitudinal Control System in a Fighter Airplane

A flight investigation was made to obtain experimental information on the handling qualities of a normal-acceleration type of automatic longitudinal control system. The control system was installed in a subsonic fighter-type airplane. In hands-off (stick-free) flight the normal-acceleration control system attempted to regulate the normal acceleration to a constant value which is dependent on the automatic-control-system trim setting. In maneuvering flight a given pilot's stick deflection produced a proportional change in normal acceleration, the change in acceleration being independent of flight condition. A small side-located controller stick was used by the pilot to introduce signals into the automatic control system. In the flight program emphasis was placed on the acceleration-limiting capabilities of the control system. The handling qualities were investigated in maneuvers such as slow and rapid pull-ups and turns and also in flight operations such as cruising, stalls, landings, aerobatics, and air-to-air tracking. Good acceleration limiting was obtained with the normal-acceleration control system by limiting the magnitude of the input signal that the pilot could introduce into the control system. The same values of control-system gain settings could be used from an acceleration-limiting stand-point at both 10,000 and 30,000 feet for the complete speed range of the airplane. The response characteristics of the airplane-control system combination were also satisfactory at both high and low altitude with these same values of control-system gain setting. In the pilot's opinion, the normal-acceleration control system provided good stability and control characteristics in flight operations such as cruising, stalls, landings, aerobatics, and air-to-air tracking

Buzz Baum: The art of cell shape

The People\u27s Republic of China (PRC) suffers greatly from problems of air pollution that also have global implications. This Article examines the PRC\u27s efforts in recent years to address the question of air quality legislatively. It uses a detailed analysis of the process through which China has developed national air pollution law to assess the impact of institutional design on such efforts and to consider Chinese legal development more generally