Evaluating TCP Mechanisms for Real-Time Streaming over Satellite Links

2006 ◽  
pp. 62-74 ◽  
Author(s):  
Panagiotis Papadimitriou ◽  
Vassilis Tsaoussidis
Keyword(s):  
Real Time ◽  
Satellite Links

Potential of combined spaceborne infrared and microwave radiometry for near real-time rainfall attenuation monitoring along earth-satellite links

2001 ◽  
Vol 19 (4) ◽  
pp. 385-412 ◽  
Author(s):  
Frank S. Marzano ◽  
Joseph F. Turk ◽  
Piero Ciotti ◽  
Sabatino Di Michele ◽  
Nazzareno Pierdicca
Keyword(s):  
Real Time ◽  
Earth Satellite ◽  
Microwave Radiometry ◽  
Satellite Links ◽  
Rainfall Attenuation

On TCP performance over asymmetric satellite links with real-time constraints

2007 ◽  
Vol 30 (7) ◽  
pp. 1451-1465 ◽  
Author(s):  
Panagiotis Papadimitriou ◽  
Vassilis Tsaoussidis
Keyword(s):  
Real Time ◽  
Time Constraints ◽  
Tcp Performance ◽  
Satellite Links

Real-Time Current and Wave Monitoring Using Acoustic and Iridium Satellite Links

2009 ◽  
Author(s):  
H. H. Shih ◽  
James Sprenke ◽  
David Trombley ◽  
John Cassidy ◽  
Tom Mero
Keyword(s):  
Real Time ◽  
Current Data ◽  
Coast Guard ◽  
Army Corps ◽  
Ocean Bottom ◽  
Time Data ◽  
Real Time System ◽  
Satellite Links ◽  
Real Time Data ◽  
The U.S

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, harbors and bays. The traditional method of obtaining real-time data from bottom mounted instruments is via underwater cable link. However, this is vulnerable to damage and costly to install and maintain. This paper describes an approach utilizing acoustic and Iridium satellite links to report in real-time wave and current data. The system consists of an ocean bottom instrumentation platform and a U.S. Coast Guard Aid-to-Navigation buoy for data relay. The bottom platform contains a Nortek 1 MHz Acoustic Wave and Current profiler (AWAC) with an integrated Nortek Internal Processor (NIP), a LinkQuest omni-directional UWM2000H underwater acoustic transmitting modem, an ORE acoustic release-based recovery component, and a Teledyne-Benthos UAT-376/EL acoustic transponder. The surface buoy supports an omni-directional UWM2000H receiving modem, an Iridium antenna, and an electronic box containing an Iridium modem, a controller, battery packs, and temperature and voltage sensors. The AWAC measures current profiles along the vertical water column at 30-minute intervals and surface waves at hourly intervals. The NIP processes a set of user selected wave and current parameters and sends these data to the controller on the surface buoy through acoustic modems. The data are then transmitted via Iridium satellite to remote offices in real-time. Sample measurement results and reference data from a near-by Datawell’s Waverider directional wave buoy are presented. The Waverider is operated by the U.S. Army Corps of Engineers (USACE) and Scripps Institution of Oceanography (SIO). Several unique system design features and interesting wave phenomenon observed at the measurement site are discussed. The goal of this project is to demonstrate the performance of AWAC, NIP, shallow water acoustic modems, and Iridium satellite in real-time data telemetry.

Real-time loss tolerant video streaming authentication for satellite links

2009 ◽  
Author(s):  
Gabriele Oligeri ◽  
Stefano Chessa ◽  
Paolo Barsocchi ◽  
Gaetano Giunta ◽  
Pauline M.L. Chan ◽  
...  
Keyword(s):  
Real Time ◽  
Video Streaming ◽  
Time Loss ◽  
Satellite Links

Some Recent Results in Quiescent Prominence Spectrometry

1979 ◽  
Vol 44 ◽  
pp. 41-47
Author(s):  
Donald A. Landman
Keyword(s):  
Real Time ◽  
Computer System ◽  
Spectral Response ◽  
Absolute Intensity ◽  
Solar Observatory ◽  
Target Size ◽  
Small Target ◽  
Signal Averaging ◽  
Quiescent Prominence

This paper describes some recent results of our quiescent prominence spectrometry program at the Mees Solar Observatory on Haleakala. The observations were made with the 25 cm coronagraph/coudé spectrograph system using a silicon vidicon detector. This detector consists of 500 contiguous channels covering approximately 6 or 80 Å, depending on the grating used. The instrument is interfaced to the Observatory’s PDP 11/45 computer system, and has the important advantages of wide spectral response, linearity and signal-averaging with real-time display. Its principal drawback is the relatively small target size. For the present work, the aperture was about 3″ × 5″. Absolute intensity calibrations were made by measuring quiet regions near sun center.

Video real-time imaging of artificial membranes during freeze-drying by cryo-electron microscopy

1988 ◽  
Vol 46 ◽  
pp. 16-17
Author(s):  
Alan S. Rudolph ◽  
Ronald R. Price
Keyword(s):  
Real Time ◽  
Self Assembly ◽  
Freeze Drying ◽  
Video Capture ◽  
Drying Process ◽  
Artificial Membranes ◽  
The Past ◽  
Cryo Electron Microscopy ◽  
Spherical Structures ◽  
Capture Techniques

We have employed cryoelectron microscopy to visualize events that occur during the freeze-drying of artificial membranes by employing real time video capture techniques. Artificial membranes or liposomes which are spherical structures within internal aqueous space are stabilized by water which provides the driving force for spontaneous self-assembly of these structures. Previous assays of damage to these structures which are induced by freeze drying reveal that the two principal deleterious events that occur are 1) fusion of liposomes and 2) leakage of contents trapped within the liposome [1]. In the past the only way to access these events was to examine the liposomes following the dehydration event. This technique allows the event to be monitored in real time as the liposomes destabilize and as water is sublimed at cryo temperatures in the vacuum of the microscope. The method by which liposomes are compromised by freeze-drying are largely unknown. This technique has shown that cryo-protectants such as glycerol and carbohydrates are able to maintain liposomal structure throughout the drying process.

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