Saturday, April 22, 2017

Satellite communications systems engineering : atmospheric effects, satellite link design and system performance / 2nd ed / Louis J. Ippolito


Wiley: Satellite Communications Systems Engineering: Atmospheric Effects, Satellite Link Design and System Performance, 2nd Edition - Louis J. Ippolito
ISBN: 978-1-119-25937-4
472 pages
April 2017

Satellite Systems Engineering Books

Satellite Communications Systems Engineering, Atmospheric Effects, Satellite Link Design and System Performance - Google Play

Description

This welcome Second Edition continues the basic premise and enhances the publication with the latest updated information and new technologies developed since the publication of the first edition.  The book is based on graduate level satellite communications course material and has served as the primary text for electrical engineering Masters and Doctoral level courses in satellite communications and related areas. [Courses | Electrical & Computer Engineering | The George Washington University] Introductory to advanced engineering level students in electrical, communications and wireless network courses, and electrical engineers, communications engineers, systems engineers, and wireless network engineers looking for a refresher will find this essential text invaluable.

Wiley: Satellite Communications Systems Engineering: Atmospheric Effects, Satellite Link Design and System Performance - Louis J. Ippolito

The first edition of Satellite Communications Systems Engineering (Wiley 2008) was written for those concerned with the design and performance of satellite communications systems employed in fixed point to point, broadcasting, mobile, radio navigation, data relay, computer communications, and related satellite based applications. Provides an invaluable, detailed coverage of atmospheric effects and their impact on satellite communications systems design and performance. Significant progress has been made in the understanding and modelling of propagation effects on radio wave propagation in the bands utilized for satellite communications. This book provides a comprehensive description and analysis of all atmospheric effects of concern for today’s satellite systems, and the tools necessary to design the links and to evaluate system performance.
This book will serve as an excellent reference to communications engineers, wireless network and system engineers, system designers and graduate students in satellite communications and related areas.
Key features:
  • Provides the state of the art in communications satellite link design and performance from the practicing engineer perspective – concise descriptions, specific procedures and comprehensive solutions
  • Contains the calculations and tools necessary for evaluating system performance
  • Provides a complete evaluation of atmospheric effects, modelling and prediction
  • Focuses on the satellite free-space link as the primary element in the design and performance for satellite communications, and recognizes the importance of free-space considerations such as atmospheric effects, frequency of operation and adaptive mitigation techniques
  • a solutions manual is available directly from the author (lippolit@gwu.edu)

Related/Background:

UC San Diego /All Collec

Satellite communications systems engineering : atmospheric effects, satellite link design and system performance / Louis J. Ippolito
Author
Ippolito, Louis J., Jr. (Louis Joseph), 1941- author
Published
Chichester, West Sussex, UK : Wiley, 2017
Edition
Second edition

Author's Previous Publications:

J. Pinder, L. J. Ippolito, S. Horan and J. Feil, "Four years of experimental results from the New Mexico ACTS propagation terminal at 20.185 and 27.505 GHz," in IEEE Journal on Selected Areas in Communications, vol. 17, no. 2, pp. 153-163, Feb 1999.
doi: 10.1109/49.748779
Abstract: The Advanced Communications Technology Satellite (ACTS) propagation experiment has collected four years of propagation data at 20.185 and 27.505 GHz. The objective of the experiment is to develop long-term statistics and modeling techniques for predicting atmospheric propagation effects in the Ka band. The experiment includes seven identical earth stations at different locations in North America. Each location is meant to characterize a unique rain region. This paper presents the data collected in White Sands, NM. The data from this site provide an excellent resource for validating rain attenuation models due to its unique arid climate with occasional high rain-rate storms. The seasonal and cumulative four-year attenuation statistics for the 20.2 and 27.5 GHz beacons are presented. The attenuation with respect to clear air (ACA) is compared to five different rain attenuation models and seven different frequency scaling models. The results illustrate how well each model predicts rain attenuation in a desert climate region
keywords: {electromagnetic wave absorption;fading;microwave propagation;rain;satellite communication;statistical analysis;tropospheric electromagnetic wave propagation;20.185 GHz;27.505 GHz;4 year;ACTS propagation terminal;Advanced Communications Technology Satellite;New Mexico;North America;SHF;White Sands;arid climate;atmospheric propagation effects;beacons;clear air;cumulative four-year attenuation statistics;desert climate region;earth stations;experimental results;fade statistics;frequency scaling models;high rain-rate storms;long-term statistics;modeling techniques;propagation data;rain attenuation models;rain region;seasonal attenuation statistics;Artificial satellites;Atmospheric modeling;Attenuation;Communications technology;North America;Predictive models;Rain;Satellite ground stations;Statistics;Storms},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=748779&isnumber=16164

D. V. Rogers, L. J. Ippolito and F. Davarian, "System requirements for Ka-band Earth-satellite propagation data," in Proceedings of the IEEE, vol. 85, no. 6, pp. 810-820, Jun 1997.
doi: 10.1109/5.598406
Abstract: Accurate estimates of the propagation impairments that affect link quality and availability and determine signal interference fields are essential for the reliable design of telecommunication systems and the efficient use of the electromagnetic spectrum. Recent announcements by commercial entities of their intent to use Ka-band spectrum to supply satellite services have heightened interest in propagation data and models for these frequencies. This paper provides a brief overview of Ka-band Earth-satellite systems and requirements in relation to the need for specific types of propagation data
keywords: {atmospheric electromagnetic wave propagation;atmospherics;fading;microwave propagation;millimetre wave propagation;satellite communication;scintillation;EHF;Ka-band Earth-satellite propagation data;SHF;link availability;link quality;propagation impairments;signal interference fields;system requirements;Availability;Downlink;Electromagnetic propagation;Frequency selective surfaces;Interference;Military satellites;Radio spectrum management;Region 2;Satellite broadcasting;Satellite communication},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=598406&isnumber=13108

H. Helmken, R. E. Henning, J. Feil, L. J. Ippolito and C. E. Mayer, "A three-site comparison of fade-duration measurements," in Proceedings of the IEEE, vol. 85, no. 6, pp. 917-925, Jun 1997.
doi: 10.1109/5.598414
Abstract: Important elements in the design of Ka-band communication systems are the duration of fade and nonfade events at a particular fade depth. The choice of modulation and forward error correcting codes will depend on both the fading time dynamics and annual fade occurrence statistics. This paper examines the fade duration measured at locations in three of the Advanced Communications Technology Satellite (ACTS) propagation experimental regions, namely, Florida (rain zone N of the radiocommunications sector of the International Telecommunications Union [ITU-R] model), New Mexico State University (ITU-R rain zone M), and Alaska (ITU-R rain zone C). Within each region, measures of the underlying uniformity are described and an interregional comparison examines the ability to scale the local results
keywords: {fading;microwave propagation;millimetre wave propagation;probability;rain;satellite communication;satellite links;statistical analysis;tropospheric electromagnetic wave propagation;ACTS propagation experimental regions;Advanced Communications Technology Satellite;Alaska;Florida;ITU-R model;Ka-band communication systems;New Mexico State University;annual fade occurrence statistics;fade-duration measurements;fading time dynamics;interregional comparison;rain zone C;rain zone M;rain zone N;three-site comparison;Artificial satellites;Attenuation;Communications technology;Error analysis;Extraterrestrial measurements;Fading;Modulation coding;Rain;Satellite broadcasting;Statistical distributions},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=598414&isnumber=13108

J. Feil, L. J. Ippolito, H. Helmken, C. E. Mayer, S. Horan and R. E. Henning, "Fade slope analysis for Alaska, Florida, and New Mexico ACTS propagation data at 20 and 27.5 GHz," in Proceedings of the IEEE, vol. 85, no. 6, pp. 926-935, Jun 1997.
doi: 10.1109/5.598415
Abstract: This paper analyzes fade slope for the Alaska, Florida, and New Mexico Advanced Communications Technology Satellite (ACTS) propagation data at 20 and 27.5 GHz for the first two years of the experiment (December 1, 1993-November 30, 1995). The propagation experiment will continue to collect data for at least another 21 months. Fade slope is examined on a statistical basis for the three sites. The Florida and New Mexico receiver sites have very different weather characteristics but almost identical elevation angles, while the Alaska receiver terminal has an extremely low elevation angle. The cumulative statistics illustrate the relationship between fade slope, fade level, transmission frequency, and elevation angle for all three sites
keywords: {fading;microwave propagation;rain;satellite communication;satellite links;statistics;tropospheric electromagnetic wave propagation;20 GHz;27.5 GHz;ACTS propagation data;Advanced Communications Technology Satellite;Alaska;Florida;Ka-band;New Mexico;elevation angles;fade level;fade slope analysis;statistical basis;transmission frequency;weather characteristics;Artificial satellites;Attenuation measurement;Communication switching;Communications technology;Joining processes;Microwave propagation;Rain;Satellite broadcasting;Satellite communication;Switching circuits},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=598415&isnumber=13108

J. Feil, L. Ippolito, M. Buehrer, G. Feldhake and S. Horan, "The first two years of experimental results from the New Mexico ACTS propagation terminal at 20.185 and 27.505 GHz," IEEE Antennas and Propagation Society International Symposium. 1996 Digest, Baltimore, MD, USA, 1996, pp. 1868-1871 vol.3.
doi: 10.1109/APS.1996.549968
Abstract: The objective of the NASA ACTS Propagation Experiment is to develop long term statistics and prediction modeling techniques for advanced satellite system design. The ACTS satellite has two beacons which illuminate North America. The experiment has seven identical receiver terminals at different locations. Each receiver terminal has meteorological sensors, two beacon receivers (20.185 and 27.505 GHz), and two total power radiometers (20 and 27.5 GHz). This report presents the first two years' (December 1, 1993-November 30, 1995) cumulative statistics for the New Mexico ACTS Propagation Terminal (APT).
keywords: {microwave propagation;rain;satellite communication;tropospheric electromagnetic wave propagation;20 GHz;20.185 GHz;27.5 GHz;27.505 GHz;ACTS satellite;Advanced Communications Technology Satellite;NASA;New Mexico ACTS propagation terminal;North America;advanced satellite system design;beacon receivers;experimental results;long term statistics;meteorological sensors;prediction modeling techniques;rain attenuation;receiver terminals;total power radiometers;Absorption;Artificial satellites;Attenuation;Meteorology;NASA;Ocean temperature;Rain;Satellite broadcasting;Satellite ground stations;Statistics},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=549968&isnumber=11272

L. J. Ippolito and T. A. Russell, "Propagation considerations for emerging satellite communications applications," in Proceedings of the IEEE, vol. 81, no. 6, pp. 923-929, Jun 1993.
doi: 10.1109/5.257689
Abstract: The effects of rain and other propagation concerns for new applications areas, currently in operation or planned for implementation by the end of this decade, are described. The areas include: VSAT systems employing low operating margins and/or low elevation angles; traditional communications applications operating with inclined geosynchronous orbits; and mobile and personal communications applications employing networks of low earth orbit (LEO) satellites. Prediction modeling and analysis techniques applicable to these areas are described. Analytical results for a range of operational parameters involving low-margin, low elevation angle, inclined geosynchronous, and LEO systems are presented
keywords: {radiowave propagation;rain;satellite relay systems;tropospheric electromagnetic wave propagation;LEO systems;VSAT systems;analysis techniques;inclined geosynchronous orbits;low earth orbit;low elevation angles;low-margin;mobile systems;operational parameters;personal communications applications;prediction modelling;rain;satellite communications;Artificial satellites;Attenuation;Business communication;Degradation;Low earth orbit satellites;Predictive models;Rain;Satellite broadcasting;Satellite communication;Telephony},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=257689&isnumber=6533

L. J. Ippolito, "Propagation effects and system performance considerations for satellite communications above 10 GHz," Global Telecommunications Conference, 1990, and Exhibition. 'Communications: Connecting the Future', GLOBECOM '90., IEEE, San Diego, CA, 1990, pp. 89-91 vol.1.
doi: 10.1109/GLOCOM.1990.116484
Abstract: Space communications systems operating in the bands above 10 GHz (e.g. 12 to 44 GHz) are considered. An overview of the major propagation problems associated with satellite communications is presented, and the impact of these factors on the design and performance of satellite systems is described. Gaseous attenuation, attenuation by rain, clouds, fog, snow, and ice, depolarization, radio noise, angle-of-arrival variations, bandwidth decoherence, and antenna gain degradation are discussed
keywords: {clouds;electromagnetic wave absorption;electromagnetic wave polarisation;electromagnetic wave scattering;fog;ice;radiofrequency interference;radiowave propagation;rain;satellite antennas;satellite relay systems;snow;tropospheric electromagnetic wave propagation;12 to 44 GHz;EHF;SHF;angle-of-arrival variations;antenna gain degradation;bandwidth decoherence;clouds;depolarization;fog;gaseous attenuation;ice;propagation problems;radio noise;radiowave propagation;rain;satellite communications;snow;space communications systems;system performance;Artificial satellites;Attenuation;Bandwidth;Clouds;Ice;Rain;Satellite broadcasting;Satellite communication;Snow;System performance},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=116484&isnumber=3389

L. J. Ippolito, "Introduction," in Radio Science, vol. 17, no. 06, pp. 1347-1348, Nov.-Dec. 1982.
doi: 10.1029/RS017i006p01347
Abstract: No abstract is available.
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7768097&isnumber=7768096

L. J. Ippolito, "Radio propagation for space communications systems," in Proceedings of the IEEE, vol. 69, no. 6, pp. 697-727, June 1981.
doi: 10.1109/PROC.1981.12049
Abstract: This paper presents a review of the most recent information on the effects of the earth's atmosphere on space communications systems. The design and reliable operation of satellite systems which provide the many applications in space and rely on the transmission of radio waves for communications and scientific purposes are dependent on the propagation characteristics of the transmission path. The presence of atmospheric gases, clouds, fog, precipitation, and turbulence cause uncontrolled variations in the signal characteristics which can result in a reduction of the quality and reliability of the transmitted information. Models and techniques used in the prediction of atmospheric effects as influenced by frequency, geography, elevation angle, and type of transmission are discussed. Recent data on performance characteristics obtained from direct measurements on satellite links operating to above 30 GHz are reviewed. Particular emphasis is placed on the effects of precipitation on the earth-space path, including rain attenuation, and rain and ice-particle depolarization. Sky noise, antenna gain degradation, scintillations, and bandwidth coherence are also discussed. The impact of the various propagation factors on communications system design criteria is presented. These criteria include link reliability, power margins, noise contributions, modulation and polarization factors, channel crosstalk, error-rate, and bandwidth limitations.
keywords: {Artificial satellites;Atmospheric waves;Bandwidth;Clouds;Crosstalk;Gases;Radio propagation;Rain;Satellite broadcasting;Terrestrial atmosphere},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1456317&isnumber=31302

L. J. Ippolito, "ATS-6 Millimeter Wave Propagation and Communications Experiments at 20 and 30 GHz," in IEEE Transactions on Aerospace and Electronic Systems, vol. AES-11, no. 6, pp. 1067-1083, Nov. 1975.
doi: 10.1109/TAES.1975.308158
Abstract: The Applications Technology Satellite (ATS-6) Millimeter Wave Experiment, developed and implemented by the NASA Goddard Space Flight Center, has provided the first direct measurements of 20-and 30-GHz Earth-space links from an orbiting satellite. Studies at eleven locations in the continental United States were directed at an evaluation of rain attenuation effects, scintillations, depolarization, site diversity, coherence bandwidth, and analog and digital communications techniques In addition to direct measurements on the 20-and 30-GHz links, methods of attenuation prediction with radars, rain gauges, and radiometers were developed and compared with the directly measured attenuation. This paper presents a review of the major results of the first year of measurements with ATS-6, with emphasis on the impact of the measurements on millimeter wave space systems design.
keywords: {Attenuation measurement;Coherence;Extraterrestrial measurements;Millimeter wave measurements;Millimeter wave propagation;Millimeter wave technology;NASA;Rain;Satellite broadcasting;Space technology},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4101533&isnumber=4101520

L. Ippolito, "Propagation and interference measurements with the communications technology satellite," 1973 Antennas and Propagation Society International Symposium, 1973, pp. 275-277.
doi: 10.1109/APS.1973.1147104
Abstract: Not Available
keywords: {Artificial satellites;Attenuation;Communications technology;Degradation;Frequency measurement;Interference;NASA;Rain;Satellite broadcasting;Satellite ground stations},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1147104&isnumber=25844

L. J. Ippolito, "Millimeter Wave Space Communications with the ATS-F Satellite," 1973 IEEE G-MTT International Microwave Symposium, Boulder, CO, USA, 1973, pp. 193-194.
doi: 10.1109/GMTT.1973.1123146
Abstract: The first space communications system operating at millimeter wavelengths is planned for the sixth NASA Applications Technology Satellite (ATS-F), scheduled for launch in April of 1974. The ATS-F experiment is designed to provide engineering data on wideband space-to-earth transmissions at 20 GHz and 30 GHz as a function of meteorological conditions and modulation techniques. This paper describes the system design for both the spacecraft and ground station portions of the experiment and emphasizes the unique design characteristics of these relatively new and unexplored frequency bands.
keywords: {Aerospace engineering;Artificial satellites;Data engineering;Design engineering;Meteorology;Millimeter wave technology;NASA;Space technology;Space vehicles;Wideband},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1123146&isnumber=24832

L. Ippolito, "Correlation measurements of 15.3 GHz attenuation and ground rainfall rate for an earth-satellite path," 1972 Antennas and Propagation Society International Symposium, Williamsburg, VA, USA, 1972, pp. 256-259.
doi: 10.1109/APS.1972.1147011
Abstract: Not Available
keywords: {Antenna measurements;Attenuation measurement;Frequency;Length measurement;NASA;Rain;Satellites;Statistics;Storms;Time measurement},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1147011&isnumber=25842

L. J. Ippolito, "Effects of precipitation on 15.3- and 31.65-GHz earth—Space transmissions with the ATS-V satellite," in Proceedings of the IEEE, vol. 59, no. 2, pp. 189-205, Feb. 1971.
doi: 10.1109/PROC.1971.8124
Abstract: The increased communications demands of a rapidly expanding technology are requiring the systems designer to look to higher frequency bands to support high data rate communications links. Virtually all terrestrial and satellite communications systems presently in service operate in bands below 10 GHz. The frequency band from 10 to 300 GHz, commonly called "millimeter waves," offers the potential for relieving the overcrowded situation at the lower frequencies. The propagation characteristics of millimeter wavelength transmission are significantly different than at the longer wavelengths, however, and propagation data is required by the systems designer as a first step in evaluating the performance characteristics of operational links. The Applications Technology Satellite (ATS-V) millimeter wave propagation experiment is the first flight experiment for the determination of long- and short-term attenuation statistics of operational millimeter wavelength earth-space links as a function of defined meteorological conditions. The ATS-V experiment, launched August 12,1969, is providing the first propagation data from an orbiting geosynchronous spacecraft in the 15-GHz (downlink) and 32-GHz (uplink) frequency bands. Several stations in the continental U.S. and Canada have been operating with the downlink transmission from the satellite since late September 1969. The spacecraft transmitter is an all solid-state phase modulated unit that provides up to 250 mW of CW power at 15.3 GHz. The 31.65- GHz uplink signal is derived from a frequency stabilized klystron, varactor upconverter, and 1000 W traveling wave tube amplifier. A multilevel computer processing program generates propagation statistics for attenuation as a function of rainfall rate, sky temperature, radar backscatter, and other meteorological variables. Downlink measurements made at the NASA Rosman, N. C. station typically show attenuations of 1 to 3 dB in light rains or dense fog; 3 to 7 dB in continuous rains (5 to 50 mm/h), and a number of fades exceeding 12 dB in heavy thunderstorms. Uplink fades of up to 18 dB in heavy rains have been observed. Correlation of measured attenuation with ground measured rainfall rate was low for a single gauge but improved significantly with height averaging of 10 - gauges. Correlation of measured attenuation with sky temperature recorded on a small aperture radiometer was very good for most storms. Valid predictions of attenuation from 16-GHz sky temperature measurements were observed for up to 15 dB of measured attenuation. The uplink to downlink attenuation ratio varied with each precipitation event and often varied during a single storm. The ratio has ranged from 2:1 to 4:1 during heavy precipitation periods.
keywords: {Attenuation measurement;Downlink;Extraterrestrial measurements;Frequency;Millimeter wave propagation;Millimeter wave radar;Millimeter wave technology;Optical attenuators;Rain;Satellites},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1450054&isnumber=31141

L. Ippolito, "Millimeter wave propagation measurements from the applications technology satellite (ATS-V)," in IEEE Transactions on Antennas and Propagation, vol. 18, no. 4, pp. 535-552, July 1970.
doi: 10.1109/TAP.1970.1139728
Abstract: A millimeter wave propagation experiment was launched on-board the Applications Technology Satellite (ATSV) in August, 1969, and is providing the first information on the propagation characteristics of the earth's atmosphere for earth-space links in theK_{u}(12.5 to 18 GHz) andK_{a}(26.5 to 40 GHz) frequency bands. Seven participating stations commenced data acquisition operations early in October, 1969. Amplitude and phase measurements on two independent test links at 15.3 GHz (downlink) and 31.65 GHz (uplink) are providing propagation characteristics during defined weather conditions. These measurements will provide the systems designer with a data base to support performance predictions for projected millimeter wave links and will aid in determining the utility of these frequency bands for communications and data-link applications. The satellite did not achieve the 3-axis earth-oriented stabilization condition that was originally planned and is presently spinning at 76 r/min at105degwest longitude, in geosynchronous orbit. Modifications have been made to the existing data analysis program which permit the conduct of meaningful propagation measurements, even with spin modulated data. Spacecraft and ground hardware systems are described, including modifications required by the satellite spin. Preliminary measurements acquired at the NASA Rosman, N. C. station during the early months of satellite operation are presented, including comparisons of attenuation with rainfall rate, sky temperature, and weather classification observations. The data available to date (March, 1970) are not yet sufficient to fully describe the long-term propagation statistics over all expected weather conditions, but they are presented here in response to requests for information on the initial characteristics of the first experimental data available from an operational earth-space millimeter wave link.
keywords: {Millimeter-wave radio propagation meteorological factors;Millimeter-wave radiometry;Radio propagation meteorological factors;Satellite communication, propagation;Atmospheric measurements;Data acquisition;Extraterrestrial measurements;Frequency;Millimeter wave measurements;Millimeter wave propagation;Millimeter wave technology;Phase measurement;Satellites;Terrestrial atmosphere},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1139728&isnumber=25480

xxxxxx

Saturday, April 15, 2017

GA-ASI is Low-Risk Option for MQ-25A CBARS Carrier UAV Competition

General Atomics Sea Avenger Predator C in MQ-25A Configuration

General Atomics Says It’s Well-Positioned as Low-Risk Option for Carrier Drone Competition
ARLINGTON, Va. — General Atomics (GA) has never built a tailhook aircraft for the Navy but that is not stopping it from competing with the Boeings, Lockheed Martins and Northrop Grummans of the world to design the MQ-25A Stingray aerial refueling unmanned aerial vehicle (UAV) for operation from aircraft carriers.
Doug Hardison, director of Marine Corps and Navy business development for GA, told Seapower his company’s leadership in fielding unmanned combat aircraft enables it to approach the problem in a different way from other companies.
The company’s proposed Sea Avenger unmanned aerial vehicle is “a natural,” said Chuck Wright, director of GA’s MQ-25A program, noting that the winged-body Sea Avenger can carry a lot of fuel, has low drag and features a large amount of space, weight and power available for payloads.
Carrier suitability will be the biggest challenge for GA in the competition, said Wright, a former Navy carrier pilot.
“We’ve retained the core of the team that started in 2011. Key engineer leads have been in the program for five to seven years,” he said.
A Predator C Avenger unmanned aircraft system and inert ordnance sit on display on a tarmac at Palmdale, Calif., Aug. 8, 2012 120808-N-WL435-054
By MC1 Peter D. Lawlor [Public domain], via Wikimedia Commons
 Hardison, a former Marine Corps helicopter pilot, pointed out that GA’s work on the EMALS Electromagnetic Aircraft Launch System and AAG Advanced Arresting Gear programs has given the company a lot of insight into carrier operations.

MQ-25 program validates future mission control system through simulated test | NAVAIR - U.S. Navy Naval Air Systems Command - Navy and Marine Corps Aviation Research, Development, Acquisition, Test and Evaluation

A team from NAVAIR simulates the operation of the future MQ-25 during a demo of the Unmanned Carrier Aviation Mission Control System (UMCS) at NAS Patuxent River, Md. in April 2017. (U.S. Navy photo)
A team from NAVAIR simulates the operation of the
future MQ-25 during a demo of the Unmanned Carrier Aviation
Mission Control System (UMCS) at NAS
Patuxent River, Md. in April 2017. (U.S. Navy photo)

Apr 13, 2017

NAVAL AIR SYSTEMS COMMAND, PATUXENT RIVER, Md. -- The Navy’s MQ-25 program completed its first demonstration representing how the mission control system located aboard the aircraft carrier will control and transmit information to an unmanned air vehicle in the future.

The April 11 demonstration validated the first build of the MD-5 Unmanned Carrier Aviation Mission Control System (UMCS), a combined hardware and software product, using representative shipboard equipment and a simulated air vehicle at NAS Patuxent River.

Related/Background:


Thursday, April 13, 2017

God's Plan For Aging



God's Plan for aging

Most seniors never get enough exercise.  In His wisdom God decreed that seniors become forgetful so they would have to search for their glasses, keys and other things thus doing more walking.  And God looked down and saw that it was good.

Then God saw there was another need.  In His wisdom He made seniors lose coordination so they would drop things requiring them to bend, reach and stretch.  And God looked down and saw that it was good.

Then God considered the function of bladders and decided seniors would have additional calls of nature requiring more trips to the bathroom, thus providing more exercise.  God looked down and saw that it was good.

So if you find as you age, you are getting up and down more, remember its God’s will.  It is all in your best interest even though you mutter under your breath.

Important facts to remember as we grow older:


  • No. 1 Life is like a jar of jalapeno peppers.  What you do today may be a burning issue tomorrow.
  • No. 2 In the 60's, people took LSD to make the world weird.  Now the world is weird, and people take Prozac to make it normal. 
  • No. 3 All of us could take a lesson from the weather.  It pays no attention to criticism.
  • No. 4 Health nuts are going to feel stupid someday, lying in the hospital, dying of nothing.
  • No. 5 Give a person a fish and you feed them for a day.  Teach a person to use the Internet and they won't bother you for weeks, months, maybe years.
  • No. 6 Men have 2 motivations: hunger and hanky panky, and they can't tell them apart.  If you see a gleam in his eyes, make him a sandwich.
  • No. 7 Good health is merely the slowest possible rate at which one can die.
  • No. 8 Life is sexually transmitted.
  • No. 9 Death is the number 1 killer in the world.

Please share this wisdom with others while I go to the bathroom again..........

Monday, April 10, 2017

March IPCSG Talk - MRI for diagnosing Prostate Cancer



Under-detection of clinically significant prostate cancer resulting from TRUS-guided biopsies.

Imaging based detection and MRI guided in-bore biopsy and diagnosis
This report was written by Bill Lewis. A DVD of the talk and presentation slides for this talk will be available 4/15/17 for purchase at IPCSG
Dr. Cooper started with a review of the state of diagnosing prostate cancer, including its
epidemiology (frequency of occurrence and comparison with other cancers), noting particularly that most men diagnosed with prostate cancer do not die from it.  Survival rates have increased over the past 25 years: the 5-year survival rate has risen from 69% to almost 99%.  The 10-year survival rate is now 98%, and the 15-year survival rate is now 95%. 
Over-detection of insignificant prostate cancer
resulting from TRUS- guided biopsies
However, current widely-used methods of screening for prostate cancer are leading to "over diagnosis" (excessive attention given to tumors very unlikely to ever become life-threatening) and over treatment.  The current gold standard of diagnosis is a TRUS (trans-rectal ultrasound) biopsy, typically involving a dozen painful insertions of sampling needles, which sample only about 1% of the prostate overall, and entirely miss sampling a large portion of the prostate (due to the use of relatively short needles, and avoiding the area near the urethra due to fear of damaging it).  As a result, 30-35% of the time, the patient is falsely thought to be free of tumors, and 35-45% of the time, those tumors that are found are thought to be less dangerous than they really are (that is, they are assigned a falsely low Gleason score).  Typically, whole gland therapy (radical prostatectomy or irradiation of the entire prostate) is given, which leads to morbidity (that is, unpleasant side effects such as incontinence or impaired sexual function).  And although many patients are put on "Active Surveillance," 25% of them harbor undetected prostate tumors that should be actively treated.   
Dr. Cooper's goal is to find "Clinically Significant" prostate cancer.  This is defined as comprising a tumor that poses a significant risk to health.  A so-called "index tumor," has a tumor volume of more than 0.5 ml (about 1/10th of a teaspoon) and/or a Gleason pattern of 4 or 5 (i.e., very abnormal-looking cells found in the biopsy).  Any tumors outside the "capsule" of the prostate (i.e., in the seminal vesicles or lymph nodes, bones or other tissues) also signify that the cancer is clinically significant.  By correctly identifying if the cancer is clinically significant, then such cancers would be treated, but clinically insignificant ones would not be treated, thus avoiding morbidity (side effects) and expense. 
The failure in the current reliance on TRUS biopsies is not that we are identifying too few cancers, but that we are identifying "too many."  Many tumors are being unnecessarily treated. 
Predictors of prognosis include the clinical stage at the time of diagnosis, from T1 to T4. However, these stages are outdated by many decades. T1 refers to tumors detected only in tissue removed during a TURP procedure ("reaming out" of the urethra to improve urine flow) or other prostate surgery. T2 means confined to the prostate, but detectable by palpation through the rectum (How primitive is that??).  T3 means spread beyond the prostate "capsule." And T4 means it has invaded other nearby structures.    
The Gleason score, a classification of prostate cancer aggressiveness on the basis of morphological characteristics, has provided the best predictor so far of patient outcome, despite many efforts at analyzing molecular and genetic expression. Visual examination of biopsy specimens -- for how abnormal the cells appear, using a pictorial reference chart to assign pattern number 1 (normal) through 5 (extremely abnormal), and then adding the pattern numbers for both the "dominant" (most often seen) and the secondary pattern, gives the "Gleason Score."
In 2005, the scoring was modified to cease reporting any pattern 1 or 2, and to change the sum to be the addition of the primary pattern plus the highest number pattern present.  Thus, if 70% of the biopsy sample corresponded to pattern 3, 20% to pattern 4, and 10% to pattern 5, under the old system the Score would be 3+4=7, but now the score would be reported as 3+5=8.  If only one pattern is present, the Score would be twice the pattern number; i.e., 6, 8, or 10.  Also note that a 4+3 Score would be considered more serious than a 3+4 score, though in both cases the sum = 7. 
There are no documented cases of a Gleason Score = 6 "cancer" (and Dr. Cooper along with many others believes that this should not even be classified as cancer) turning into metastatic disease.  
The prostate gland is shaped like an upside down pyramid, starting in young adulthood at about the size of a walnut, and gradually enlarging.  It has two main zones: The peripheral zone on the outside, comprising 70-80% of the tissue, with most of the rest considered the central zone, with some transition zone.  The base is near the bladder, and the apex is the point at the bottom.  Toward the back on both lower sides is the neurovascular bundle; damage to which causes sexual dysfunction and incontinence. 
Most tumors occur in the peripheral zone (consistent with its comprising most of the prostate), but more of the remaining tumors are found in the transition zone than in the central zone.  Only the peripheral zone is reached in most TRUS biopsies. 
Digital rectal exams identify the presence of a tumor in only 14-28% of men with prostate cancer.  The PSA test is indicative, but very non-specific (with interference from other causes), and TRUS biopsies have huge problems with accurately detecting prostate tumors, discussed in the talk. 
In contrast, MRI can provide an accurate test to detect, localize (and 85% of the time, there is more than one tumor), stage (determine if the disease is confined to the prostate or not), and guide the biopsy of the disease.  A study published in 2011 showed 98-100% accuracy in detecting tumors using mpMRI, and sensitivity was highest with the most serious tumors (as is appropriate), as confirmed by subsequent removal and biopsy of the prostate. 
Multiparametric-MRI (mpMRI) consists of a number of computer-aided detection processes:  T2-weighted images, useful for finding transition zone tumors; DWI (diffusion-weighted image) & ADC (apparent diffusion coefficient) for peripheral zone tumors; Axial T1 (for overall anatomy and to see the neurovascular bundle); and DCE (dynamic contrast enhancement). 
In an MRI, a magnetic field 15-30,000 times as strong as the earth's magnetic field is used to cause the protons to line up in one direction.  Then a radiofrequency pulse (similar to FM radio waves) is uses to "knock" some protons out of alignment.  As they return to alignment, some energy is released and detected.  The T1 and T2 parameters are based on this detected energy.  If you like details, know that the T1 energy is the basic "return 90 degrees back into alignment," and the T2 energy is the slight wobbling, or “precessing,” of the spinning proton as it recovers from the pulse.  It's the opposite of a spinning top falling over.  If it fell straight down, that would be pure T1.  But it wobbles and gradually falls closer and closer to the ground.  The wobbling is T2, but the overall falling is T1.  Got it?  It turns out that one signal is better for some purposes (e.g., T2 to see tumors in the transition zone), and the other is better for other visualization (i.e., overall anatomy, including the neurovascular bundle). 
The DWI & ADC show and measure the rate of diffusion of water within the tissue.  The tissue in peripheral zone tumors is more dense than healthy prostate tissue, so the movement of water molecules is restricted enough to be detected (DWI) and even quantified (ADC).  If the diffusion coefficient is below 900 mm2/sec, it is strong evidence of a tumor, and the value correlates very well with the Gleason Score!  Dynamic contrast enhancement (DCE) refers to images obtained as a tracer chemical injected into the patient is rapidly taken up preferentially by tumor cells, and then also quickly released back into the bloodstream.  The tumor is highlighted in a bright red color, in the images generated by the software. 
Regarding the hardware, Dr. Cooper explained that the differences between 1.5T and 3T (strength of the magnetic field) images, and studies with or without the endorectal coil (somewhat better images, but uncomfortable to the patient and more expensive), all are washed out by the issue of how well the machine is "tuned." 
A number of Prostate Cancer cases detected by mpMRI were shown, with their various images.  The procedure for MRI-guided biopsy was described, including how it can be used to precisely guide the needle into the suspicious areas identified in the diagnostic mpMRI.  Patients (including this writer) report that it is practically non-painful, in great contrast to reports of traditional TRUS biopsy pain.  (Trivia note:  An 18-gauge needle is used, and gauge means "how many needle barrels fit side-by-side in an inch). 
Tumors of Gleason Score 9-10 were easily and straightforwardly found in MRI-guided biopsies, where no tumor had been found in 2-5 prior TRUS biopsies, in four examples shown.  A published study in Urology in 2010 showed that in 71 consecutive patients with PSA higher than 4 ng/ml, and at least two prior negative TRUS biopsies, that an mpMRI diagnosis and MRI-guided biopsy found cancer in 60% of these men.  More importantly, 93% of the tumors were "clinically significant."  Also, more than half of the tumors were in the apex or anterior side of the prostate, where TRUS biopsies don't reach.  
Here's the contrast:  TRUS biopsies miss 30-35% of prostate cancers.  mpMRI misses only 3% of Gleason Score 4+3 tumors, and only 10% of 3+4 tumors.  TRUS biopsies under-grade the Gleason Score 35-45% of the time.  mpMRI with MRI-guided biopsy under-grades only 5% of the tumors (based on subsequent biopsy after prostate removal).     
Current and proposed diagnostic pathways
A new technique is promising:  The UroNav system uses an mpMRI diagnostic image superimposed on a trans-rectal ultrasound image, to localize the suspected tumors for biopsy.  The ultrasound image can show where the prostate is, and can give real-time images of where the biopsy needle is.  The superimposed image shows where the tumor is.  This may give even more accuracy than the current MRI-guided biopsy procedure, which requires sliding the patient in and out of the machine, to first take an image, then operate the needle insertion equipment, then put the patient back into the machine for the next view of the process.  Dr. Cooper likes the new system, and would like to use it in his practice.  A study published in 2015 showed that the UroNav system gave 30% more detection/diagnosis of high-risk cancers, and desirably less detection of low-risk cancers, than standard biopsies.  Still, the tumor detection yield to date is best with MRI-guided biopsy.     
Cash costs for mpMRI at Imaging Healthcare Specialists are $400 without contrast (if the patient is allergic to the contrast agent), or $575 with contrast agent injection.  For an MRI-guided biopsy, the cash cost is $1600, but may be covered by Medicare at 100%.   (Cost questions?  Call Tami Colbert at 858-658-6416.)
Questions:  What if you can't have an MRI?  Reasons would be an old-type pacemaker, or a surgical clip in the brain, but most clips in other parts of the body would be OK.  Axumin PET/CT (very recently FDA approved, and used a dozen times so far by Dr. Cooper) and PSMA scan technologies were explained as possible alternatives. 
The expense of medicine going up is partly due to doctors purchasing expensive imaging equipment, then "overusing" it to increase their billings.  The Deficit Reduction Act tried to counter this by reducing payouts for scans. 
MRI after radiation?  The radiation is terribly damaging, so the images are not as distinct as otherwise.  And usually in those cases, a whole-body scan is appropriate. 
PIRAD is an acronym, "prostate imaging reporting and data" system, developed from BIRAD reporting of breast cancer, to standardize reports.  The system can be learned about online, or from additional slides from Dr. Cooper that are included with the video that will be available for purchase online or at our next meeting.  The BIRAD system is used at Imaging Healthcare Specialists, and at several other organizations in our area.
The extra slides also cover "problems" with Gleason Scores, and  the new 2016 WHO Gleason grading system, which has Grade Groups from 1 to 5, corresponding to Gleason Scores "6 or less," 3+4, 4+3, 8 and "9-10." 
The role of MRI in detection, localization and staging is summarized in the extra slides.   An intriguing slide listed four options for treating prostate cancer:  Active Surveillance (for Gleason Score 6 when PSA <10 and="" beam="" biopsy="" brachytherapy="" by="" cryotherapy.="" ditto="" external="" localized="" low="" mpmri="" mri-guided="" on="" or="" prostate="" prostatectomy="" radical="" span="" style="mso-spacerun: yes;" the="" to="" undetectable="" volume="">  That last warrants extra explanation.  And what about other local therapies that might be guided by MRI or UroNav, such as NanoKnife?
The American Urologic Association guideline statements (five in all) were summarized.  The updated statements from 2013 were also summarized.
Final slides:  TRUS: Who gets biopsied?  PSA explained, with both positive and negative issues.  PSA velocity and density explained.  Again, all the extra slides are included with the video that can be purchased for $10.