排序方式： 共有7条查询结果，搜索用时 15 毫秒
1
1.
The authors discuss the current measurement accuracy of the RD Instruments 1200-kHz acoustic Doppler current profiler (ADCP) in the near surface and bottom boundaries. Data are presented from tests. In the first series of tests, an ADCP was mounted on a bottom sled in an upward looking mode. The sled was towed at known speeds with and without surface waves. Additionally, tests were conducted with several acoustic baffle designs installed in the transducer head. The 1200-kHz ADCP has the ability to accurately measure mean currents in a dynamic wave induced flow field. Sidelobes can bias the measurements at 85% of the range when bottom or surface boundaries are present. The amount of bias is strongly dependent on surface wave characteristics. Sidelobe bias can be eliminated with a properly designed baffle system. The profilers have the ability to measure wave particle velocities with a properly configured system 相似文献
2.
THE DEVELOPMENT of testing techniques and procedures required to understand the performance of devices used to measure water currents has proven to be one of the most difficult and challenging tasks that the oceanographic community faces. It has long been recognized that some type of controllable relative water motion was a necessary element in the process of determining the accuracy of a current meter. A widely accepted solution is the towing tank where a current meter fastened to a moving carriage is moved through "still" water. A simple measurement of carriage speed over the ground compared to the current meter's flow measurement gives an indication of the accuracy of the device. Although this approach satisfied many, a sense that this technique was not sufficient spawned a few short-lived attempts at simulating time-varying flow conditions and developing deterministic models (transfer functions) for the response of inertial transducers. In addition, mathematical modeling of the motion of buoy moorings was attempted by a variety of investigators. In the late 1960's and early 1970's, the response of a current meter to the complex time-varying ocean environment became a major issue within the oceanographic community. It was clear that this information could not be obtained by simple steady-flow tow tank testing and that either dynamic controllable techniques must be developed or our ability to characterize the measurement environment must be improved. 相似文献
3.
Omissions in the subject paper, especially lack of reference to one 1968 paper by the author of this letter, may tend to mislead the reader. The subject paper was perhaps too brief to clear the record. 相似文献
4.
Acoustic Doppler backscattering techniques have been exploited for measuring water velocity for nearly 40 years. Although most early applications centered on measuring ship speed, much work has been done during the last 20 years to adapt the techniques to measure oceanic velocity fields. The purpose of this paper is to summarize the work that has been done and to discuss the state of acoustic Doppler technology. 相似文献
5.
6.
7.
Appell G.F. Mero T.N. Bethem T.D. French G.W. 《Oceanic Engineering, IEEE Journal of》1994,19(2):149-157
A port information system was developed for Tampa Bay, FL, that provides data in real time. Current, water level, and weather systems measure various parameters from around the bay and report at 6-min intervals via a packet-modern-controlled telemetry system. A central receiving station and data acquisition system process the data and make it available in various formats. A voice data response system provides immediate access to the data via touchtone telephone. A voice processor is used to compose phrases that provide a user with environmental information based on the selection made from the voice menu. The design and development of all aspects of the system are described. This system has proven to be a valuable asset to the local and regional marine community, providing information for safe navigation, oil spills, search and rescue, fishing, and existing weather conditions 相似文献
1