Feasibility of wireless data transmission on ships

This report will present the results of an investigation into the feasibility of several modes of wireless data transmission including: (1) radio frequency modems, (2) acoustic modems (using the ship's steel hull for a path with a "HullPhone"), (3) power line systems, such as X-lO units, and (4) possible power line utilization of telephone modems. There is a need for wireless data transmission on both Voluntary Observing Ships (VOS) and research ships for short-term installations. The availability of cables from remote areas on these ships is usually not good, and restrictions on installing cables prevent some useful measurements from being made. A case in point is the real time availability of measurements of sea surface temperature (SST) from VOS by sensors mounted inside the hull. Instruments for measuring SST are installed in sealed compartments that are near the waterline of the ship and often four decks below the main deck. Other applications include transmission of data from automated XBT launchers located on the aft deck to the science area and transmission of data from a cluster of meteorological instruments located at the bow of the ship to the bridge for interface to Service Argos or Inmarsat satellte links. Surveys of existing equipment have been made. Typical equipment has been purchased and tested in a ship environment, including the "HullPhone." The results of these tests are presented. Suggestions for system configurations to meet the applications noted above are made with note of the product development required.Funding was provided by the National Science Foundation through Grant No. OCE96-32461

Alvin titanium electrical penetrator design, manufacture, and testing : interim report

Under the U.S. Navy's Project TITANES a new titanium alloy pressure hull has been designed, built, and installed for use in the deep-submersible ALVIN. The Woods Hole Oceanographic Institution was assigned the task of designing, procuring and testing the through-hull electrical penetrators for the new sphere. This interim report traces the progress of this Woods Hole program from the initial design stage, through the various phases of manufacture and electrical testing, to the installation of the units in the completed hull, and the numerous laboratory~ pressure tank, and at-sea tests conducted to verify the satisfactory performance of the new penetrators. The results of all laboratory and in-service testing done to date support the conclusion that the performance of the titanium penetrators meets all of the original specifications.Office of Naval Research Contract No. NOr014-73-C-0097 NR 265-10

A self-contained wind speed, direction and location system for buoys and ships in the World Ocean Circulation Experiment

Knowledge of the absolute wind velocity near the surface of the ocean is a requirement of the World Ocean Circulation Experiment (WOCE) and other large programs directed towards understanding air-sea interactions and how ocean circulation and climate are interrelated. The measurement is made possible using IMET (Improved METeorology) modules, a next generation meteorological data acquisition system developed as part of the WOCE program. An IMET system consists of a set of intelligent modules for each measurement variable, with data being recorded on a computer, typically PC-based. The IMET wind module includes a propeller for wind speed, a vane and optical encoder for wind direction, a flux gate compass for the north reference, and microprocessor-based electronics for control and data formatting. The IMET Global Positioning System (GPS) module includes a five chanel GPS receiver and microprocessor based electronics for control and data formatting. These modules, as part of the complete measurement suite, result in a self-contained system that can make accurate measurements from research ships, drifting and moored buoys, and volunteer observing ships (VOS).Funding was provided by Grant No. OCE-8709614 from the National Science Foundation

Intelligent chilled mirror humidity sensor

A new, intelligent, chilled mirror humidity instrument has been designed for use on buoys and ships. The design goal is to make high quality dew point temperature measurements for a period of up to one year from an unattended platform, while consuming as little power as possible. Nominal system accuracy is 0.3°C, and a measure of data quality is provided to indicate possible drift in calibration. Energy consumption is typically 800 Joules per measurement; standby power consumption is 0.05 watts. Control of the instrument is managed by an onboard central processing unit which is programmable in BASIC, and communication to an external data logger is provided through an RS232 compatible interface. This report describes the preliminary sensor tests that led to this new design and provides the complete technical description required for fabrication.Funding was provided by the Office of Naval Research under contract Number N00014-84-C-0134, and the National Science Foundation through grant Number OCE87- 09614

Development of an autonomous aerosol sampler for ocean buoys and land sites

The authors have successfully designed, built and tested an aerosol sampler which is capable of collecting, in an unattended manner, a time-series set of aerosol samples (aerosol-embedded filters) from moored ocean buoys and remote areas on land. Research on aerosols, in particular, and atmospheric chemistry, in general, has not been previously attempted from buoys. Aerosols entering and leaving the ocean play an important role in climate change, ocean productivity, pollutant transport and atmospheric optics. This report discusses (1) the scientific applications of a buoy-mounted aerosol sampler, (2) the advantages of using buoys as research platforms and (3) the authors' new instrument. Also discussed are the results of a four month test of the aerosol sampler on the AEROCE (Atmosphere/Ocean Chemistry Experiment) tower in Bermuda and the results of a three month test on a buoy moored in Vineyard Sound off Woods Hole, MA USA. The direct comparison between WHOI filters and AEROCE filters from the Bermuda tower is very encouraging as the Fe concentrations of aerosols compare to within 10-15% over a wide range of values. Aerosol sampling from a buoy moored in coastal waters was successfully tested under a variety of atmospheric and oceanic conditions.Funding was provided by the National Science Foundation through Grant No. OCE-943212

Improved meteorological measurements from buoys and ships (IMET) : preliminary analysis of solar radiation and motion data from IMET test buoy

Data are analyzed from a test buoy equipped with a motion sensor (Hippy) and two different pyranometers in order to understand and quantify motion induced errors in meteorological data. The Hippy measures pitch, roll, heave and acceleration of the buoy. Probability density functions and spectra of buoy motion and insolation are constructed and discussed.Funding was provided by the National Science Foundation under Grant No. OCE-87-0961

A pulsed light command system for the scamp platform and Alvin

This report describes the pulsed light command system used on an ancillary platform designed to augment the task capabilities of the submersible ALVIN. Deep submersibles are called on to perform increasingly complex tasks on the bottom of the ocean. Many tasks that are not within the capabilities of a specific submersible can be accomplished by using an ancillary platform. The submersible then assumes the roll of controller much in the same manner as tug boat or even a tractor trailer cab in controlling the load carrying vehicle. The ancillary platform carries the load and provides for the special task requirements. Control of this platform underwater then becomes the primary submersible task. Mating and unmating connectors at depth is one part of the task and is generally an unsatisfactory operation because alignment is difficult and electrical insulation resistance is of low quality. In addition most submersibles have a limited number of electrical wires penetrating the hull that can be made available for control purposes. Some type of command link is required that does not require hull penetrators, has reasonable alignment requirements, can be mated and unated underwater many or unlimited times and provides good command reliability. Since most submersible have viewports, a pulsed light transmitter through a viewport was reviewed and found to satisfy all of the requirements. There are no wiring modifications required and the transmitter unit can be easily installed and removed as required. an acoustic link was considered but this would have required some ships wiring. In addition, there are many acoustic devices on submersibles and interference would be an important consideration. Finally, the pulsed light technique has not been investigated as extensively as acoustic methods and is interest as an alternative approach. A project to evaluate the feasibility of ancillary platforms with a pulsed light command link was carried out. This project was called SCAMP for Self Contained Ancillary Modular Platform.Office of naval Research Contract No. N00014-71-C-028

A low cost adaptable heading hold system for Alvin

This report describes a low cost heading hold system that has been operational on the DSV ALVIN since October 1975. This system reduces pilot fatigue during straight line transits and allows the pilot to more effectively monitor the overall operation.Office of Naval research Contract No. N00014-73-C-0097; NR 265-10

Oil filled electrical cables external to the pressure hull on DSV Alvin

This report provides background information on undersea cables of conventional construction and of the oil filled type. Design considerations for oil filled cable systems are presented as well as description of the ALVIN oil compensated electrical system. Descriptions of individual components used in the ALVIN system are provided as well as operating experience. This information is of use in designing oil filled electrical cables external to the pressure hull of any submersible

Alvin gyrocompass performance report : 5 June 1974 to 15 September 1974

This report documents the performance of two gyrocompasses used on ALVIN between 5 June and 15 Sept., 1974. During this period ALVIN participated in Project FAMOUS and completed a series of dives on the new England Sea Mounts. A Gyrosystems, Inc., Model 800 gyrocompass was used from June 5th until August 9th. A Sperry Marine Systems Company subminiature gyrocompass was used from August 9 through September 15. The Sperry and Gyrosystems compasses provided an accuracy within several degrees when cmpared to the ship's compass. The data does not represent a controlled evaluation since it was impossible to take reading simultaneously on ALVIN's and the support ship's compasses. Therefore this report should be considered as an at sea operational evaluation. Within the limitations of the evaluation and using the method described for calculating "offset" and "average error" the following summary comparison can be made. The Sperry gyrocompass had an average error of about 1.4°. The Gyrosystems Model 800 had an average error of 4.6°