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Subsurface mooring allows researchers to measure the ocean properties such as water temperature, salinity, and velocity at several depths of the water column for a long period. Traditional subsurface mooring can release data only after recovered, which constrains the usage of the subsurface and deep layer data in the ocean and climate predictions. Recently, we developed a new real-time subsurface mooring (RTSM). Velocity profiles over upper 1 000 m depth and layered data from sensors up to 5 000 m depth can be real-time transmitted to the small surface buoy through underwater acoustic communication and then to the office through Beidou or Iridium satellite. To verify and refine their design and data transmission process, we deployed more than 30 sets of RTSMs in the western Pacific to do a 1-year continuous run during 2016–2018. The continuous running period of RTSM in a 1-year cycle can reach more than 260 days on average, and more than 95% of observed data can be successfully transmitted back to the office. Compared to the widely-used inductive coupling communication, wireless acoustic communication has been shown more applicable to the underwater sensor network with large depth intervals and long transmission distance to the surface.

Knowing the location of military personnel and vehicles plays an essential role in military operations, especially when these operations take place in jungles or places of dense vegetation. In this article, the use of the GPS network for the positioning of military vehicles is proposed, in addition, this location is reported through the Iridium satellite network. After the tests, the location of the device is sent, received and stored, with an approximate error of 2m using geodesic points to verify the accuracy of the equipment.

A current- and pressure-recording inverted echo sounder (CPIES) placed on the sea floor monitors aspects of the physical ocean environment for periods of months to years. Until recently, acoustic telemetry of daily-processed data was the existing method for data acquisition from CPIES without full instrument recovery. However, this approach, which requires positioning a ship at the mooring site and operator time, is expensive and time-consuming. Here, we introduce a new method of obtaining data remotely from CPIES using a popup-data-shuttle (PDS), which enables straightforward data acquisition without a ship. The PDS data subsampled from CPIES has 30–60 min temporal resolution. The PDS has a scheduled pop-up-type release system, so each data pod floats to the sea surface at a user-specified date and relays the recorded data via the Iridium satellite system. We demonstrated the capability of an array of PDS-CPIES via two successful field experiments in the Arctic Ocean. The data acquired through the PDS were in agreement with the fully recovered datasets. An example of the data retrieved from the PDS shows that time-varying signals of tides and high-frequency internal waves were well captured. GPS-tracked trajectories of the PDS floating free at the sea surface can provide insights into ice drift or ocean surface currents. This PDS technology provides an alternative method for remote deep-ocean mooring data acquisition.

In this paper, iridium satellite communication based integrated Marine environment observation system is studied. There are some problems in the deep ocean, such as bad environment, difficult release of anchored buoy, single measurement of Marine environmental data and low accuracy of Marine environmental data. The system is designed to carry a variety of sensors that transmit real-time observations to a land-based monitoring center via iridium satellite communications. In this way we can get integrated Marine environmental data. The data of systematic observation is of great significance for improving the accuracy of Marine meteorological forecast, Marine ecological environment protection, further research on global Marine climate change and network observation.

This paper presents a data acquisition and telemetry system designed and built to monitor oceanographic and meteorological parameters. A voltage regulator and readout module was designed for the reading of data from a set of dedicated commercial sensors and to continuously monitor the voltage level of the power supply. In order to monitor the measured parameters and the status of the buoy remotely, a data string was transmitted every hour using an Iridium satellite transceiver. The described system was implemented and tested in four coastal oceanographic buoys that were deployed and operated in remote sites in the Gulf of Mexico (GoM) for several months in 2016. The data recorded by the buoys is used to describe the oceanographic and meteorological conditions at each site. The system proved to be reliable for long-term monitoring at offshore sites, requiring only minor corrective maintenance during their operation in the field.

Expendable bathythermographs (XBT) to profile upper-ocean temperatures from vessels in motion have been in use for some 50 years now. Developed originally for navy use, they were soon adapted by oceanographers to map out upper-ocean thermal structure and its space–-time variability from both research vessels and merchant marine vessels in regular traffic. These activities continue today. This paper describes a new technology—the Autonomous Expendable Instrument System (AXIS)—that has been developed to provide the capability to deploy XBT probes on a predefined schedule, or adaptively in response to specific events without the presence of an observer on board. AXIS is a completely self-contained system that can hold up to 12 expendable probes [XBTs, XCTDs, expendable sound velocimeter (XSV)] in any combination. A single-board Linux computer keeps track of what probes are available, takes commands from ashore via Iridium satellite on what deployment schedule to follow, and records and forwards the probe data immediately with a time stamp and the GPS position. This paper provides a brief overview of its operation, capabilities, and some examples of how it is improving coverage along two lines in the Atlantic.

In view of the problem of poor real-time transmission of the traditional information transmission method of marine monitoring buoy, the transmission speed is slow. Based on this, iridium data communication system is applied to the information transmission of ocean monitoring buoy. Through the establishment of the overall framework of Iridium satellite communication system, determine the buoy information transmission network protocol. On the basis of the network protocol, use Iridium satellite data communication system to obtain the location information of the marine monitoring buoy, and then process the obtained information. Finally, upload the processed buoy information to complete the transmission of the marine monitoring buoy information. Compared with the traditional method of information transmission of ocean monitoring buoy, the experimental results show that the method of information transmission of ocean monitoring buoy using iridium data communication system can complete the transmission of buoy information in a shorter transmission time, with better real-time transmission.

Several post-detection approaches to the mitigation of radio-frequency interference (RFI) are compared by applying them to the strong RFI from the Iridium satellites. These provide estimates for the desired signal in the presence of RFI, by exploiting distinguishing characteristics of the RFI, such as its polarization, statistics, and periodicity. Our data are dynamic spectra with full Stokes parameters and 1[Formula: see text]ms time resolution. Moreover, since most man-made RFI is strongly polarized, we use the data to compare its unpolarized component with its Stokes I. This approach on its own reduces the RFI intensity by many tens of dBs. A comprehensive approach that also recognizes non-Gaussian statistics, and the time and frequency structure inherent in the RFI, permits exceedingly effective post-detection excision provided full Stokes intensity data are available.

With the increasing demand for large-scale data transmission and data security in deep sea observation and detection, Iridium and Beidou dual-mode communication has become the main approach in the field of China’s ocean observation and detection. However, the size and weight of the two antennas are not easy to reduce, which presents a challenge to the buoyancy control system of carriers such as deep sea ARGO buoys. According to the fact that the RDSS L frequency band of Beidou satellite is similar to that of Iridium Satellite system and partly coincides with Iridium frequency band, this paper provides the potential of using Beidou deep sea antenna for Iridium communication. Firstly, the electrical characteristics of existing Iridium and Beidou antennas on the market are measured in microwave anechoic chamber and SATIMO system. Then the outdoor measurements are conducted. The results show that the Beidou deep sea antenna can be used for Iridium communication.

Field-aligned currents (FACs) play an important role in the coupling between the ionosphere and magnetosphere. Numerical simulation of these phenomena is of increasing interest, but validation has been hampered by a lack of a formal framework to compare simulations to satellite-derived products. We develop a statistical approach to compare FAC simulations from global magnetohydrodynamical models against satellite products. We introduce a robust algorithm that automatically detects and defines regions 1 and 2 FACs. In an example, currents derived from the Iridium satellites are compared against simulated currents from two resolutions of the Lyon-Fedder-Mobarry model on one solar event. We assess both average and structured discrepancies, the former being a level shift of the physical model away from the satellite product, while structural discrepancy refers to time-varying, continuous differences. For this event, the lower resolution version of the Lyon-Fedder-Mobarry is shown to be a poor representation of the satellite-derived FACs, while the higher resolution version substantially reduces discrepancy.

This paper describes a system for providing power and communications to moored profiling vehicles. A McLane Moored Profiler (MP) was equipped with a rechargeable battery pack and an inductive charging system to allow it to move periodically to a charging dock at the top of a subsurface mooring. Power was provided from a large bank of alkaline batteries housed in two 0.94-m steel spheres. Data were transferred inductively from the profiler to a mooring controller, and from there back to shore via radio and Iridium satellite modems housed in a small surface communications float on an “L” tether. An acoustic modem provided backup communications to a nearby ship in the event of loss or damage to the surface float. The system was tested in a 180-m-deep fjord (Puget Sound, Washington) and at Station ALOHA (A Long-Term Oligotrophic Habitat Assessment), a 4748-m-deep open-ocean location north of Hawaii. Basic functionality of the system was demonstrated, with the profiler repeatedly recharging at about 225 W (with an overall efficiency of about 70%). Data were relayed back to shore via Iridium and to a nearby ship via the radio and acoustic modems. The system profiled flawlessly for the entire 6-week test in Puget Sound, but charging at the deep site stopped after only 9 days in the deep-ocean deployment owing to damage to the charging station, possibly by surface wave action.

The paper presents a description and the technical characteristics of an autonomous hydroacoustic station developed at the Pacific Oceanological Institute, Far Eastern Branch, Russian Academy of Sciences (TOI DVO RAN) for stationary measurements of variations in acoustic pressure in the frequency range of 2–15 000 Hz on the shelf at the bottom. To organize real-time monitoring of the parameters of seismic survey impulse signals and industrial acoustic noise, the station is additionally equipped with a digital UHF–FM radio telemetry channel. Acoustic data measured in the frequency band of 2–2000 Hz is transmitted through the channel to a shore post, as well as via an Iridium satellite radio telemetry channel. It controls the operation of the UHF–FM radio transmitter and transmits the results of special analysis of acoustic data obtained in subsequent 1 min time intervals.

For a better understanding of the air-sea interactions that occur during typhoons and improved accuracy in typhoon forecasting, the Institute of Oceanography at the National Taiwan University has developed a buoy that can measure meteorological and hydrographic conditions, and transmit the high-precision data in near real-time. The buoy captures various types of meteorological data, including air temperature, air pressure, relative humidity, wind speed and direction, rainfall, and solar radiation. Additionally, the buoy measures key hydrographic data, such as the temperature and salinity profiles of the upper 500-m water layer. The newly designed of buoy system is a low-power-consumption system and it can be in sleep mode between successive samplings to save power energy. The buoy is supplied electric power by lithium batteries and it can support buoy operation for more than 18 months. The sampling interval and data transmission rate are adjustable via Iridium satellite or UHF radio communications. When a typhoon approaching buoy, the operator can transmit a command to buoy via Internet/Iridium satellite communications to change data transmission rate from standard mode to intensive mode. In addition, the raw data can be retrieved through UHF radio communication between the buoy and a nearby ship. A prototype and two improved buoys were deployed off southeastern Taiwan for trial in summers of 2015 and 2016, respectively. These buoys survived nine typhoons and successfully collected important data on all nine of them. The detail of buoy system and mooring design are presented in this paper.

In order to get the ice melting rate and the acousto-optic reflection characteristics of sea ice profile, the acoustic ranging system and the auxiliary environment parameter measurement system are developed. The instrument collects the underwater ultrasonic sensor's data via the RS485 bus, store the data to SD card and then send them to computer by iridium satellite. Its main advantages are that lossless, non-contact and high precision so that it is suitable for melting information monitoring of sea ice. In the paper the proposed hardware architecture and software architecture are presented. Due to the result obtained during the experimental tests, the proposed instrument can be considered as a reference of monitor application on sea ice melting.

We present the development considerations and design for ground-based instrumentation that is being deployed on the East Antarctic Plateau along a 40° magnetic meridian chain to investigate interhemispheric magnetically conjugate geomagnetic coupling and other space-weather-related phenomena. The stations are magnetically conjugate to geomagnetic stations along the west coast of Greenland. The autonomous adaptive low-power instrument platforms being deployed in the Antarctic are designed to operate unattended in remote locations for at least 5 years. They utilize solar power and AGM storage batteries for power, two-way Iridium satellite communication for data acquisition and program/operation modification, support fluxgate and induction magnetometers as well as a dual-frequency GPS receiver and a high-frequency (HF) radio experiment. Size and weight considerations are considered to enable deployment by a small team using small aircraft. Considerable experience has been gained in the development and deployment of remote polar instrumentation that is reflected in the present generation of instrumentation discussed here. We conclude with the lessons learned from our experience in the design, deployment and operation of remote polar instrumentation.

Two Seaglider autonomous underwater vehicles were deployed as mobile receiving platforms in a 2016–2017 tomography experiment in the Canada Basin. The introduction of gliders into a tomography experiment has the advantage of adding acoustic data receptions at many depths and ranges relative to moored acoustic sources. The challenge in interpreting these data is the lack of statistics at any given location and the uncertainty in the glider position during a dive, the latter resulting in a fundamental ambiguity between the position and sound speed. The acoustic arrival matching localization technique, performed in post-processing, has been employed to position the instruments while underwater using transmissions from moored acoustic sources. This technique capitalizes on the broadband nature of the tomography sources and estimates latitude and longitude while relying upon the vehicle’s pressure sensor for depth. Acoustic ranging was also performed onboard the gliders during the deployment, and estimated ranges from the moored sources were transmitted via Iridium satellite link every few hours when the glider surfaced. Positions resulting from acoustic arrival matching localization will be compared with results based on semi-real time acoustic ranging. Results will be discussed in the context of reviewing the state of the art in underwater glider localization.

During the past decade engineering-grade magnetic field measurements from the low Earth orbiting (LEO) Iridium constellation of communication satellites have been available to the geospace science community as a tool to map field-aligned currents. The Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) applied to Iridium measurements markedly improved the temporal and spatial resolution of these data. We developed new methods to compare data from the latest improvement to AMPERE with those from a constellation of four LEO Defense Meteorological Satellite Program (DMSP) spacecraft that carry high-resolution magnetometers. To perform the comparisons, we transformed all data to a common coordinate frame and altitude (110 km) and developed a means of computing spacecraft magnetic conjunctions. These conjunctions yield discrepancies in the magnetic field perturbations measured at each proximate spacecraft. During the geomagnetic disturbance of 29–30 May 2010, the vector differences in the horizontal perturbations at closest approach (typically a few tens of kilometers) had mean, median, and standard deviation values of 132 nT, 112 nT, and 90 nT, respectively. The DMSP spacecraft tend to report larger perturbations in the northern polar cap and cusp regions, especially during active intervals. We attribute some of the differences to limitations of spacecraft-attitude knowledge that propagate into AMPERE data. Overall, for the magnetic storm, we provide clear evidence that AMPERE data can provide high-resolution auroral zone data in good agreement with DMSP data for use in data assimilation algorithms. Such dual-use commercial data can provide important global augmentation to the nation's space weather monitoring capabilities.

This paper describes the design, analysis, and evaluation of new ionospheric measurement error models for high-integrity multiconstellation navigation systems, The robustness of the newly derived models is experimentally evaluated using months of dual-frequency global positioning system (GPS) data collected at multiple locations, In parallel, an integrity analysis is devised to quantify the impact of traveling ionospheric disturbances on user position, Finally, overall carrier phase positioning performance is assessed over continental areas for various combinations of GPS and Galileo and Iridium satellites.

The Automated Meteorology–Ice/Indigenous species–Geophysics Observation System (AMIGOS) consists of a set of measurement instruments and camera(s) controlled by a single-board computer with a simplified Linux operating system and an Iridium satellite modem supporting two-way communication. Primary features of the system relevant to polar operations are low power requirements, daily data uploading, reprogramming, tolerance for low temperatures, and various approaches for automatic resets and recovery from low power or cold shutdown. Instruments include a compact weather station, single- or dual-frequency GPS, solar flux and reflectivity sensors, sonic snow gauges, simplified radio-echo sounder, and resistance thermometer string in the firn column. In the current state of development, there are two basic designs. One is intended for in situ observations of glacier conditions. The other supports a high-resolution camera for monitoring biological or geophysical systems from short distances (100 m to 20 km). The stations have been successfully used in several locations for operational support, monitoring rapid ice changes in response to climate change or iceberg drift, and monitoring penguin colony activity. As of August 2012, there are nine AMIGOS systems installed, all on the Antarctic continent or in the surrounding ocean.

Automatic Dependent Surveillance Broadcast (ADS-B) reception via satellite is surveillance technique that used to provide information from aircraft. Reception via satellite is intended to expand the coverage of ADS-B terrestrial. Thus, Iridium and Globalstar with the altitudes of 800 km and 1400 km respectively is utilized for comparisons. Altitude of the satellite affect the radius that is used to calculate the density of the aircraft that the satellite can coverage. The simulation result show that the footprint radius of Iridium satellite and Globalstar is 836.6 NM (Nautical Miles) and 1083 NM respectively which means the higher the altitude, the coverage also increase. On the other hand the optimum pulse duration of the ADS-B signal is 50 μs for Globalstar satellite and 120 μs for Iridium satellite. Consequently shorter pulse duration of ADS-B signal results in less message that can be transmitted.

To monitor and better understand temperature and salinity conditions in the Arctic Ocean interior, we developed a new Argo-type ocean profiling system for the polar oceans. This Polar Ocean Profiling System (POPS) consists mainly of an ice platform and an Argo-type subsurface CTD profiler. The ice platform includes a system controller that manages all data acquisition, processing, formatting, and messaging. Iridium satellite communication technology sends the observation data and also allows remote commands to be sent from the laboratory to the buoy. The profiler is mounted on an oceanographic cable interfaced to the platform; the profiler moves along the cable between depths of 10 and 1000 m. The inductive modem system provides data transfer between the ice platform and the profiler. In April 2005, field tests of the POPS were conducted in the Arctic Ocean near the North Pole. Later on, commands were sent via Iridium from the laboratory to the buoy to change the data sampling acquisition frequency, allowing us to obtain 14 temperature and salinity profiles during the first 22 days. We confirmed that POPS could measure temperature and salinity with conservative accuracies better than 0.01 °C for temperature and 0.01 for salinity. Following this test, we initiated the observation of the Arctic Ocean from 10 m down to 1000 m depths in April 2006 using POPS, and we also started sending the data to the global telecommunication system (GTS) in real time. These data are the first Argo data sent from the Arctic Ocean. Not only Arctic oceanographers but also everyone who is interested in Arctic oceanographic conditions can easily access these data from the Argo data server.

Traditional methods of measuring the propagation of waves originating from ocean swell and other sources have relied on wire strain gauges, accelerometers or tiltmeters. All methods required constant attention to keep in range, while data recovery has demanded that the instrument site be revisited. In this paper, we describe the use of ultra-sensitive tiltmeters and novel re-zeroing techniques to autonomously gather wave data from both polar regions. A key feature of our deployments has been the use of the Iridium satellite communications system as a way of ensuring continuous data recovery and remote control of the instrumentation. Currently four instruments have been successfully reporting from the Arctic Ocean for over 18 months, with two further units deployed in 2005, one in the Weddell Sea, Antarctica, and one additional unit in the Arctic.

The ultra-long duration balloon (ULDB) Pathfinder Project is developing a small pumpkin balloon system and a new communication package based on the iridium satellites technology to demonstrate a global, 100-day duration capability that is scalable to the full-scale ULDB. A set of trade studies has been conducted to determine the volume, mass and cost of the balloon system to support up to 90 kg payload mass to an altitude of 35 km. The Pathfinder test balloons will provide valuable data in the development of performance models for future ULDB flights. The iridium based communication package will include a power subsystem, a command and data-handling unit, a GPS receiver, and an iridium L-Band Transceiver (LBT) for global communications. The flight data will include, at a minimum: latitude, longitude, altitude, horizontal and vertical speeds, heading, time, and other balloon performance parameters (i.e., system voltages, temperatures, etc.). Although the system will be designed for global launch capability, initial flights will be launched from the proposed full-scale ULDB mission launch locations. This paper will present and discuss the initial series of trade studies conducted for the development of the pathfinder balloon and the design concept of the iridium based communication package.

The Iridium® System satellite constellation consists of 66 satellites in circular, polar, 780 km altitude orbits in six equally spaced planes. Each satellite carries an engineering magnetometer which has sufficient resolution to sense the Birkeland currents. This paper presents a spherical harmonic fitting (SHF) technique for estimating field aligned currents (FACs) using the cross track component of the magnetic field measurements from the Iridium satellites. The SHF magnetic field perturbations along with Ampere's law are used to derive the global FACs from 40° MLAT to the pole in either hemisphere. Data for 10–11 UT, 23 August, 1999 were obtained from Iridium, Defense Meteorology Satellite Program (DMSP) Fl3 and the Ultraviolet Imager (UVI) onboard the POLAR satellite. The SHF data were evaluated along the DMSP F13 track. The range of east-west component, SHF magnetic perturbations from Iridium was (−530,465) nT compared with ( −630,634) nT from DMSP F13. The derived upward FACs ranged from −0.8 to 0.9 µAm−2. Upward FACs were co-located with bright dayside UVI emissions.

Following the catastrophic collisional breakups of three intact spacecraft (Fengyun 1C, Cosmos 2251, and Iridium 33) occurred in low-Earth orbit, a detailed analysis was carried out, with a dedicated software tool (SDIRAT ― Space Debris Impact Risk Assessment Tool), in order to evaluate the additional impact flux of cataloged objects on the satellites of two operational constellations in high inclination orbits, Iridium and COSMO-SkyMed. As of May 1, 2011, the flux increase with respect to the debris background was 160%, on average, for the Iridium satellites, distributed on six equally spaced orbit planes at 781 km, and 47% at the altitude of the COSMO-SkyMed constellation, using a single orbit plane at 623 km.

The Chinese astronomical exploration in Antarctic region has been initialized and stepped forward. The R&D roadmap in this regard identifies each progressive step. For the past several years China has set up Kunlun station at Antarctic Dome-A, and Chinese Small Telescope ARray (CSTAR) has already been up and running regularly. In addition, Antarctic Schmidt Telescopes (AST3_1) was transported to the area in the year of 2011 and has recently been placed in service for some time and followed with telescopes in larger size predictably more to come. Antarctic region is one of a few best sites left on the Earth for astronomical telescope observation, yet with worst fundamental living conditions for human survival and activities. To meet such a tough challenge it is essential to establish an efficient and reliable means of remote access for telescope routine observation. This paper outlines the remote communication for CSTAR and AST3_1, and further proposes an intercontinental network control platform for Chinese Antarctic telescope array with remote full-automatic control and robotic observation and management. A number of technical issues for telescope access such as the unattended operation, the bandwidth based on iridium satellite transmission as well as the means of reliable and secure communication among other things are all reviewed and further analyzed.

Mountains along the northwestern coast of Ellesmere Island, Canada, possess the highest peaks nearest the Pole. This geography, combined with an atmospheric thermal inversion restricted to below ∼1000 m during much of the long arctic night, provides excellent opportunities for uninterrupted cloud-free astronomy - provided the challenges of these incredibly remote locations can be overcome. We present a miniaturized robotic observatory for deployment on a High Arctic mountaintop. This system tested the operability of precise optical instruments during winter, and the logistics of installation and maintenance during summer. It is called Ukpik after the Inuktitut name for the snowy owl, and was deployed at two sites accessible only by helicopter, each north of 82 degrees latitude; one on rock at 1100 m elevation and another on a glacier at 1600 m. The instrument suite included at first an all-sky-viewing camera, with the later addition of a small telescope to monitor Polaris, both protected by a retractable weather-proof enclosure. Expanding this to include a narrow-field drift-scanning camera for studying extra-solar planet transits was also investigated, but not implemented. An unique restriction was that all had to be run on batteries recharged primarily by a wind turbine. Supplementary power came from a methanol fuel-cell electrical generator. Communications were via the Iridium satellite network. The system design, and lessons learned from three years of operation are discussed, along with prospects for time-domain astronomy from isolated, high-elevation polar mountaintops., Ground-Based and Airborne Telescopes IV, July 1-6, 2012, Amsterdam, Netherlands

The navigation performance of Iridium satellite is simulated and analyzed based on STK from two aspects—the number of visible satellites and geometric dilution of precision (GDOP). Meanwhile we compare it with GPS and GALILEO system to demonstrate its performance. Experiment shows that the Iridium satellite system has a good coverage merit at two poles, which is even better than that of GPS and GALILEO. However, its global coverage is unstable and GDOP changes sharply from high latitude area to low latitude area which means Iridium satellite cannot orientate or navigate around the equator well. Then we explore the application fields of the Iridium satellite system.

Both waves and currents rank highly by user groups among oceanographic observation variables. Real-time information of these variables is especially useful for vessel operators and recreational users in and around ports, harbors and bays. Other applications include coastal land management, ecosystem protection and restoration, mitigation of coast hazards and marine accidents, forecast, warning and search and rescue. The U.S. National Ocean Service (NOS) of NOAA maintains and operates a Physical Oceanography Real-Time System (PORTS®) in the Nation's major ports and harbors. Typical hydrological parameters measured include water levels, currents, conductivity, water temperature and depth. Wave information is of interest to PORTS® users, but has only been obtained recently in a few PORTS® sites. However, continued study and laboratory and field testing of various wave measurement instruments and real-time data telemetry technologies have been conducted since 2003. These instruments and technologies include Triaxys Directional Wave buoy, Directional Waverider buoy, and acoustic Doppler current profilers, underwater acoustic modem and links with radio and satellite. Extraction of non-directional wave information from near shore tide gauges (e.g., air acoustic gage and microwave radar altimeter) has also been studied. Among these, acoustic Doppler current profilers (or ADCP) are of particular interest since they are key instrument in PORTS® for current measurements. It is economically and functionally attractive to measure both currents and waves. This paper summarizes the NOS operational system and results of two NOS field studies of real-time ADCP systems for current and wave measurements in ports and harbors. The operational system includes bottom-mounted ADCP with buried cable in the navigation channel. Later, the system was replaced by a U.S. Coast Guard Aid-to-Navigation (ATON) buoy-mounted ADCP with telemetry radio. Shore based Horizontal ADCPs are also being used for real-time current measurement. The two studies (in 2003 and 2008) used different ADCP instruments and data telemetry techniques. The ADCPs used were RDI Workhorse series and AWAC (with internal processor). The underwater acoustic modems used were models UWM1000 and UWM2000H by LinkQuest. The data telemetry technologies used were FreeWave 900MHz spread spectrum line-of-sight radios, and Iridium satellite.

Liquid Robotics, Inc. (LRI) has developed an autonomous vehicle, the Wave Glider®, which utilizes wave energy for propulsion, Iridium® Satellite for command, control and data exfiltration and GPS satellite transmissions for positioning. The vehicle consists of a low-profile surface float outfitted with solar panels, energy storage and shore communication infrastructure and a subsurface wing located at approximately seven meters depth connected to each other by a sophisticated tether. The wing is designed to respond to the wave energy at its depth in such a way that it provides propulsion for the vehicle toward any location chosen by the operator. The wave energy thus harnessed by the vehicle can be used for locomotion to any point of interest as well as for station keeping (by driving in a tight circle) once that position is reached. Real time communication with the shore-based operator allows monitoring of platform's location and data gathered, commanding movement to a new position, or even complete repurposing of the mission. The capability of the Wave Glider® to accomplish its mission in a variety of environments with a variety of mission profiles is now well proven. In addition, the Wave Glider® is of course capable of carrying a variety of sensor payloads. LRI and Teledyne RD Instruments (TRDI) have now partnered to provide current profile measurements from the vehicle. An initial encouraging field test in 2009 showed the feasibility sufficiently to merit further work, though there was some indication that asymmetric motion of the surface float (it tends to skate on wave faces in some sea states) combined with low resolution GPS sampling could be biasing the velocity measurements. This led to additional testing of a Wave Glider® equipped with an ADCP, higher resolution GPS and an Inertial Motion Unit in 2010. Once the extensive integration project was completed sufficiently, a new field campaign was launched for comparison of the new, more integrated Wave Glider® ADCP measurements with those of a bottom mounted Workhorse ADCP that was deployed as an independent reference. The mission profile for this field campaign included programming the Wave Glider® to circle between the shallow water in which the reference ADCP was deployed to the deeper water of a submerged canyon. In this way measurements could be taken in shallow water, where bottom tracking capability could be effectively relied upon to remove platform motion, and in deeper water where the bottom was out of range and the relative motion of the platform removed by other means. Given the change in depth, there is no reason to assume the reference ADCP measurements are valid in the deeper water. However, comparison of the reference instrument in the shallow water with the relative velocity removed by bottom track and by the other methods can prove the utility of the other methods, and continuity of measurement between the shallow, referenced and deep, unreferenced regimes would indicate that the measurement in both instances is correct. We report on the initial results of the field testing, and on the current status of the integration.

Underwater passive acoustic directional sensors and Seaweb through-water networked acoustic communications are implemented in the Intracoastal Waterway at Morehead City, North Carolina on the U.S. eastern seaboard. The objective is to demonstrate capability for first-alert protection of a high-value port facility against asymmetric threats that intelligence sources indicate are arriving via watercraft. Battery-powered acoustic sensors are rapidly deployed at widely separated chokepoint locations in shallow 5–10 meter water. These sensors autonomously detect the passage of a maritime vessel and generate a contact report indicating time, location and heading of the target. Seaweb through-water acoustic communications delivers the contact report via a scalable wide-area underwater network including multiple acoustic repeater nodes and a radio/acoustic communications (Racom) gateway buoy. The Racom gateway telemeters the contact report via Iridium satellite communications to an ashore command center with low latency. The in situ acoustic detection is corroborated using shore-based video surveillance to classify the contact as friendly or actionable.

Astronomers are ever dreaming of sites with best seeing on the Earth surface for celestial observation, and the Antarctica is one of a few such sites only left owing to the global air pollution. However, Antarctica region is largely unaccessible for human being due to lacking of fundamental living conditions, travel facilities and effective ways of communication. Worst of all, the popular internet source as a general way of communication scarcely exists there. Facing such a dilemma and as a solution remote control and data transmission for telescopes through iridium satellite communication has been put forward for the Chinese network Antarctic Schmidt Telescopes 3 (AST3), which is currently under all round research and development. This paper presents iridium satellite-based remote control application adapted to telescope control. The pioneer work in China involves hardware and software configuration utilizing techniques for reliable and secure communication, which is outlined in the paper too.

The extreme environment of Antarctic greatly benefits astronomical observations. Site testing works already show the excellent seeing and transmission on Dome C. And the higher, colder inland plateau Dome A is widely predicted as even better astronomical site than Dome C. Preliminary site testing carried out since the beginning of 2008 shows that Dome A has lower boundary layer and lower precipitable water vapour. Now the automated seeing monitor is urgently needed to quantify the site's optical character which is necessary for the telescope design and deployment. We modify the commercial telescopes with diameter of 35cm to function as site testing DIMM and make it monitor both seeing and isoplanatic angle at the same time automatically on Dome A at different height. Part of the processed data will be transferred back by Iridium satellite network every day. The first DIMM will be deployed on Dome A in early 2011.

Coastal mountains at Canada's northern tip possess many of the desirable properties that make the Antarctic glacial plateau attractive for astronomy: they are cold, high, dry, and in continuous darkness for several months in winter. Satellite images suggest that they should also benefit from clear skies for a fraction of time comparable to the best mid-latitude sites, and conventional site-selection criteria point to good seeing. In order to confirm these conditions, we are testing three mountain sites on northwestern Ellesmere Island, in Nunavut. On each we have installed a compact, autonomous site-testing station consisting of a meteorological station, a simple optical/near-infrared camera for sensing cloud cover, and - at one site - a more advanced all-sky viewing camera. The systems were deployed by helicopter and run on batteries recharged by wind (a compact methanol fuel cell is under study as a supplementary power source). Effective two-way communications via the Iridium satellite network allows a limited number of highly compressed images to be transferred. The full-winter dataset is stored at the site on flash-drives, thus requiring a return visit to retrieve, but day-to-day station performance can be assessed using telemetry and a computer model. Based on site-testing results, the plan is to select one site for the addition of a seeing monitor and a small but scientifically productive telescope.

The Iridium communications satellite constellation is a swarm of 66 LEO satellites in 6 pole-crossing orbits. Iridium LLC plans a NEXT generation to be launched 2013-16, and has invited secondary "bolt and go" payloads from Earthobserving agencies. A swarm of infrared imagers on Iridium-NEXT could track water vapor and clouds to estimate the unobserved winds above the 55-60 degree latitude limit of geosynchronous satellite imagery. This kind of polar overpass data has been demonstrated to significantly improve medium-range weather forecasts by tracking water vapor features at 6.7 microns in successive images near the pole from NASA's MODIS instruments. A "Boreas" instrument design is proposed for a push-broom imager combining two miniature sensors: uncooled microbolometric cameras gathering 4- band infrared radiometry, and small star trackers providing attitude information. An autonomous instrument package has been designed with low mass, power, and data rate. The "Boreas" instrument would use the Iridium constellation itself to relay the raw imagery from 3 successive images to ground stations that would navigate the data and extract wind vectors. Wind vectors could be generated automatically for the polar caps every few hours, and delivered for assimilation into numerical weather models during Iridium-NEXT operations, during 2016-2030.

The height of the atmospheric boundary layer on the Antarctic plateau is of particular importance to designers of optical telescopes for Antarctica. Snodar was developed at the University of New South Wales to measure the height of the atmospheric boundary layer at Dome A and Dome C on the Antarctic plateau. Snodar, or Surface layer Non-Doppler Acoustic Radar, is a true monostatic high-frequency acous tic radar (SODAR) operating between 5 kHz and 15 kHz. As the height of the boundary layer at Dome C is expected to be less then 30 m, and unknown at Dome A, Snodar was designed to have a minimum sampling height of 5 m with a vertical resolution of 1 m or better. Snodar uses a PC/104 computer to perform signal processing in real time, and a USB sound card for low-latency analog IO. Snodar was designed to run autonomously storing data on USB flash disks for retrieval the following summer, while uploading of data acquisition scripts and spot checking of data is possible via Iridium satellite through UNSW's PLATO facility. Snodar also incorporates a unique in-situ calibration sphere. We present details of the design and results from testing of Snodar. Keywords: atmosphere, boundary layer, SODAR, Antarcti ca, Antarctic plateau, astronomy, site-testing

As part of the transition of the Tropical Atmosphere Ocean (TAO) program, NOAA's National Data Buoy Center (NDBC) is testing commercial off-the-shelf (COTS) components to replace obsolescent sensors. The ldquorefreshrdquo of TAO will also include changing to a transmission system that allows hourly receipt of high-resolution data, and incorporating a new payload. Six refresh buoys will be deployed within 10 kilometers of existing TAO buoys. Meteorological and ocean sensors will be compared in order to verify that the refresh system replicates the data provided by the ldquolegacyrdquo TAO system. Two refresh buoys have already been deployed along the TAO 140degW line at 9degN and 2degS. . An analysis of the first three months of oceanographic data from these two buoys is presented and discussed. The temperature sensors were compared in a laboratory setting and the results were very good. While the ocean temperatures from the refresh buoys are reported at ten minutes intervals every hour via the Iridium satellite constellation, the legacy buoys report ten minute data over Service ARGOS as the polar satellites pass the buoys. At the 2degS,140degW site, eight of the ten ocean temperature sensors reported data that is statistically equivalent to the legacy buoy temperatures. The other two refresh temperature sensors at 20 and 80 meter depths failed to report. Five of the ten ocean temperature sensors at the 9degN, 140degW site reported statistically equivalent data. Data from two of the legacy TAO sensors were failed by TAO analysts prior to deployment of the TAO program. Comparison of the other three temperature sensors yielded results that were not statistically equivalent. The region between 40 and 120 meters depth is characterized by a sharp temperature gradient. The environment may be responsible for the variability between the sensors in this region. Following recovery of the legacy and refresh buoys during fall 2008, the 10 minute data from the temperature sensors will be downloaded and NDBC and the NOAA's Pacific Marine Environmental Laboratory will perform an in-depth analysis.

An avionics system for an autonomous UAV platform supporting VHF depth sounding and SAR is under development. The system is divided into navigation, communication, and data processing or logging. This design provides accurate position, velocity, acceleration, and attitude data. It supports over-the- horizon communication via an Iridium satellite link. The data collected by this system will allow for motion effects of the UAV to be compensated for, to enable SAR image formation.

A package has been developed to assist investigation of the availability percentage of non-geostationary satellites. The package is general and can be used to simulate the availability percentage for all regions on both sides of the equatorial orbit. Further, the availability percentage for any specific country can be determined. The availability percentage time of Globalsatr, Iridium and Molniya constellations are simulated with this package for different points on earth.

An integrated system of intelligent acoustic buoys have been developed to detect, identify and localize whales in real-time in their environment and communicate this information to land-based stations or ships via satellite and Internet, and RF communications. The low-cost portable buoy network can be used as a marine mammal observatory to gather continuous space-time series of vocalizing animals over large basins, or as early warning systems for improving whale protection on navigation routes or around moving or fixed platforms during threatening high-level acoustic activity. The unit buoy is powered by two 12-V batteries connected to solar panels. The processor is an 800 MHz Pentium III PC equipped with 400-MB fast memory and a 100-GB hard disk. The clock is synchronized with the embarked GPS. Data from two georeferenced hydrophones equipped with depth and temperature sensors are flowing to a 16-bit 500-kHz A/D-DSP board. Two-way communication is through 900-MHz and an Iridium satellite modems. Specific whales target calls are detected in time-frequency domain after adaptive noise-filtration. The selected master buoy collects the precisely time-tagged detections from all units via RF communication, and locates the calling whales from hyperbolic and isodiachron-Monte Carlo fixing algorithms. A simple tracking algorithm then builds the individual tracks. All acoustic data or users' selected portions of them can be stored on the hard disk. The system is designed to accommodate future developments and be easily adapted to various tasks. It can be deployed as a drifting network or anchored to the bottom, as well as from the ice sheet. First sea trials will be in August 2006 in the St. Lawrence

A moderate bandwidth observatory platform has been developed that integrates acoustic and satellite links to provide connectivity between sensors on the seafloor and investigators on shore. The system incorporates high-rate (5300 bps) acoustic modems, solar power generation, a low-power single board computer running Linux, and Iridium satellite modems to provide a lower cost, relocatable alternative to higher bandwidth systems. The prototype system, which supports an ocean bottom seismometer (OBS) and fluid-flow, temperature, and resistivity sensors, has been deployed near the Nootka Fault in 2326 m of water off the coast of Vancouver Island since May 2004. Since deployment, the system has transmitted more than 150 MB of data from the seafloor instruments

The GeoRangerTM high-resolution airborne magnetic survey system is now available to the petroleum and mining industries. The result of a two-year cooperative research and development program between The Insitu Group and Fugro Airborne Surveys, these stateof-the-art Unmanned Aerial Vehicles complement traditional manned airborne magnetic aircraft. Specifically, these Unmanned Aerial Vehicles provide safe and efficient alternatives for data acquisition offshore, at low altitudes and in remote or harsh locations. Capable of fully autonomous 3D flight, the GeoRangerTM has an endurance of over 10 hours and cruises at 75 kilometers per hour. Using the point-location launch and recovery systems (patents pending), the GeoRangerTM can be operated from undeveloped sites in close proximity to survey areas. The advanced technology of the GeoRangerTM includes features such as full error-analysis capability, providing a return-to-base command in the event of difficulties while in flight and Iridium satellite communications providing the operator with continuous system status, position and velocity updates. This paper discusses market impetus, development, and operational success of GeoRangerTM in Canada including analysis of data quality which is comparable to conventional survey aircraft.

The Tumbleweed rover, currently under development at the Jet Propulsion Laboratory (JPL) in Pasadena, California, is a large, windblown, inflated ball, which carries an instrument payload in its interior. Such rovers offer an effective and simple means of gathering data over large spatial extents of Earth, Mars, and other solar system bodies. Tumbleweeds could prove to be a safe and economical way of deploying instruments such as a ground penetrating radar or a magnetometer in numerous hostile environments. The latest version of the rover was recently deployed in Greenland, where it completed a more than 130km autonomous traverse across an ice sheet. Communicating via the Iridium satellite network, the rover in question successfully and reliably relayed live GPS, temperature, and pressure data to a ground station at JPL for nearly ten days. The follow-on rover is currently being readied for a traverse from the South Pole to the coast of Antarctica some 2000km away. The Antarctic test is set to take place in February of 2004 and will serve to verify Tumbleweed as an effective means of harvesting data in extreme and remote settings.

A DMON digital acoustic monitoring device has been integrated into a Seaglider with the goal of passive, persistent acoustic monitoring of cetacean populations. The system makes acoustic recordings as it travels in a sawtooth pattern between the surface and up to 1000 m depth. It includes three hydrophones, located in the center of the instrument and on each wing. An onboard real-time detector has been implemented to record continuously after ambient noise has risen above a signal-to-noise (SNR) threshold level, and the glider transmits power spectra of recorded data back to a shore-station computer via iridium satellite after each dive. The glider pilot has the opportunity to set parameters that govern the amount of data recorded, thus managing data storage and therefore the length of a mission. This system was deployed in the vicinity of the Hawaiian Islands to detect marine mammals as an alternative or complement to conventional ship-based survey methods. System design and implementation will be described and preliminary results will be presented.

While it is technically possible to record high bandwidth ambient noise, practically the ocean ambient sound data need to be subsampled and interpreted for users. A new configuration of Argo float has been augmented with passive aquatic listener (PAL) technology to monitor the ocean ambient sound during the drift phase of the Argo float mission, typically at 1000 m depth for 10 days at a time. These ocean ambient sound data are interpreted as wind speed, rainfall rate, and marine animal detections. These data are reported to users via two‐way iridium satellite communication link when the float surfaces at the end of each dive cycle. Changes in sampling strategies can be implemented if desired. The first set of these floats has been deployed and additional deployments are ongoing. The data will be used to study the fresh water cycle of the ocean as part of the NASA Aquarius/SAC‐D satellite mission scheduled to be launched this year.

The satellite constellation of Iridium LLC, which filed for Chapter 11 bankruptcy in 1999 after it failed to win enough business for its commercial satellite communications services, is still orbiting at an altitude of about 780 kilometers. Now, however, the satellites are helping to write a new chapter in understanding space weather. Magnetometers onboard each of the system's 66 polar-orbiting satellites are working in conjunction with the high-frequency, multinational Super Dual Auroral Radar Network, or SuperDARN, to provide the first continuous measurements of electrical currents between Earth's upper atmosphere and space. These tools also are generating the first global maps of electrical power flowing into the polar upper atmosphere.

Five years in the making, the National Astronomy and Ionosphere Center (NAIC) and Motorola, Inc. signed a memorandum of understanding in March that extends some protection from interference to radio astronomers who use the Arecibo Radio Telescope in Puerto Rico. Motorola, which operates the IRIDIUM commercial communications satellite system, has agreed to guarantee 8 hours of radio observing time each day—from 10:00 p.m. to 6:00 a.m. U.S. Eastern Standard Time (6:00–11:00 UT)—that is free of potential signal interference from its satellites. With 66 IRIDIUM satellites scheduled to be operational in low-Earth orbit this fall, the agreement had taken on some urgency.