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What feature does the SINCGARS use to reduce the threat of jamming and minimize the use of direction-finding equipment to establish your location?
SINCGARS radio's frequency hopping covering the 30 to 87.975 MHz band in 2,320 channels. Older direction-finding equipment that use a conventional receiver channel will have trouble direction-finding a frequency hopping radio, but direction-finders sets that use what amounts to a spectrum analyzer can DF a frequency hopping radio, and probably can de-interleave a number of them, so the anti direction-finding part of the reason for frequency hopping is not too strong. Note that SINCGARS uses about 100 hops per second, which is considered a slow hop. It is not a direct sequence spread spectrum system like is used by GPS. Once a frequency hopping radio has been located by direction-finding equipment then it's possible to jam it. Not by knowing the hop sequence, but by listening for each new transmission (like using a very fast spectrum analyzer) and then jamming that transmission, then the next, and so on. So the advantage of Frequency Hopping against a sophisticated enemy has a short life.
What tools do astronauts use in space?
There are quite a few tools that the Astronauts use, though for construction and maintenance in space, the Pistol Grip Tool (PGT) is the primary tool of choice. Its predecessor was the Power Ratchet Tool (PRT), originally developed and created for servicing the Hubble Space Telescope. Problems with a battery tether, battery time, bulkiness, and a lack of torque limiter/controls, led the Goddard Space Flight Center to design the PGT as the follow-up replacement for the PRT. The design was so successful (in other words, the Astronauts liked it) that it beat out a competing design for a tool for constructing the International Space Station by the Johnson Space Center. The PGT is essentially designed like a cordless drill, except that it has 3/8" socket on the end. In fact, NASA originally approached the Black and Decker corporation to see if they were interested in designing it, but they declined due to the costs involved (PR would've been great though). There are drum selections for torque, speed, and the information is available as a digital LED readout on the electronics package on top. Though some sources today say the PGT uses a NiMH battery, it was originally designed and flown with Lithium Ion battery packs; NASA spent over a half-million dollars on Lithium Ion technology for the program, leading eventually to its widespread use today. In addition to the PGT, retainers, tethers, a trace gas analyzer (to ensure there's no leakage of gases present while they're working), sun shield (incorporated as part of their helmet) are the other standard tools for working in space. There are a couple of PGT pictures on my Supervisor bio page; I was the Quality Rep responsible for the PGT program for NASA when it was being constructed and tested prior to HST's Second Servicing Mission in 1997.
What spacecraft landed on Venus?
On March 1, 1966 the Venera 3 Soviet space probe crash-landed on Venus,becoming the first spacecraft to reach the surface of another planet. Thedescent capsule of Venera 4 entered the atmosphere of Venus on October 18, 1967,making it the first probe to return direct measurements from another planet's atmosphere.None of these missions reached the surface while still transmitting.The first successful landing on Venus was by Venera 7 on December 15, 1970.It remained in contact with Earth for 23 minutes, relaying surface temperatures.Venera 8 landed on July 22, 1972. In addition to pressure and temperatureprofiles, a photometer showed that the clouds of Venus formed a layer, endingover 22 miles above the surface.The Soviet probe Venera 9 entered orbit on October 22, 1975, becoming the firstartificial satellite of Venus. The 1,455 lb descent vehicle separated from Venera 9and landed, taking the first pictures of the surface and analyzing the crust.On October 25, 1975 Venera 10 arrived and carried out a similar program of study.In 1978, NASA sent two Pioneer spacecraft to Venus. Four probes entered theVenusian atmosphere on December 9, followed by the delivery vehicle. Althoughnot expected to survive the descent through the atmosphere, one probe didcontinue to operate for 45 minutes after reaching the surface.Also in 1978, Venera 11 and Venera 12 flew past Venus, dropping descentvehicles on December 21 and December 25 respectively. Each lander mademeasurements with a nephelometer, mass spectrometer, gas chromatograph,and a cloud-droplet chemical analyzer. Strong lightning activity was alsodetected.In 1981, the Soviet Venera 13 sent the first colour image of Venus's surface andanalysed the X-ray fluorescence of an excavated soil sample. The probeoperated for a record 127 minutes on the planet's hostile surface.Also in 1981, the Venera 14 lander detected possible seismic activity in theplanet's crust.In December 1984, during the apparition of Halley's Comet, the Soviet Unionlaunched the two Vega probes to Venus. Vega 1 and Vega 2 encountered Venusin June 1985, each deploying a lander and an instrumented helium balloon.The landing vehicles carried experiments focusing on cloud aerosol compositionand structure. They were the last probes to land on Venus for decades.
Is there life on Mars?
As for the existence of intelligent life on Mars now or in the past, there has never been any evidence that could support that conclusion. The same goes for other bodies in our solar system other than our own planet. Advanced life forms as we know them require liquid water. Since the mid 1960's, we've known about the presence of frozen water at the Martian poles. The presence of liquid water on Mars, however, has never been proven. Until liquid water is found on the Red Planet (hint - the place to look would be at receding glacier melts in solar system bodies), the odds of any life forms or microbes abiding on Mars is extremely remote.In recent years, NASA Rover robots on Mars (Mars Pathfinder, the Spirit and Opportunity Rovers and the Phoenix Mars Lander) coupled with data from Mars orbiters proved the previous existence of liquid water on Mars billions of years ago, thus raising the spectre that life had once arisen on Mars during the early solar system and perhaps died out. Billions of years ago, Mars was a hot planet harboring shallow salty seas. The hematites (dubbed 'blueberries') discovered by the Spirit and Opportunity Rovers are a remnant of those early seas. A new study of a system of gullies on the surface of Mars recently published in the March 2009 issue of the journal Geology, appears to indicate that the most recent period of water flow on the Red Planet was only 1.25 million years ago. That gully system was located on the inside of a crater in Promethei Terra, observed in close-up images taken by the NASA Mars Reconnaissance Orbiter HiRISE camera. If that interpretation of those images is correct, it may mean that Mars goes through warming and cooling cycles and that some liquid water may flow during warmup.The Phoenix Lander, which studied Mars for some months after its landing on May 25, 2008, conducted various experiments testing the Martian soils at that site. Phoenix conducted wet chemical analysis through its Microscopy, Electrochemistry and Conductivity Analyzer or MECA, which mixes the soil sample with water and bakes the mud to 1832°F to test for chemical composition. The results show the martian soil had a pH between 8 and 9, meaning it is alkaline -- the kind of soil you could grow vegetables in if you brought it back to Earth, tossed in some cow manure and watered it regularly. MECA detected the presence of magnesium, sodium, potassium and chloride but no carbon, the crucial ingredient necessary for life on Earth. Interestingly, JPL tells us that the mineral content of the soil is not much different from the upper dry valleys in Antarctica. What Phoenix' wet chemical analysis strongly suggests, however, is that there was no life in the soil sample tested by MECA. The Phoenix Lander's follow-the-water strategy for searching for organic compounds is, to be sure, exactly the right strategy for NASA to pursue. The European ExoMars rover will drill down 2 meters into the surface for its tests. Missions to Enceladus or Titan (or elsewhere in the solar system where liquid water might be found), may similarly find no trace of lifeforms. Even on Earth, however, simple organisms have survived once removed from a source of water. The existence of Earth-like life should necessarily be restricted to planets where Earth conditions exist or have existed. No evidence of life on Mars, or on any other body in the solar system other than Earth, has been uncovered. The quest for other life, of course, does not stop at the edge of our solar system. Astronomers are eagerly searching for exoplanets outside of our sun's orb. The Hubble Team has recently discovered carbon dioxide in the atmosphere of HD 189733b, a Jupiter-like gas giant exoplanet. Previous observations of HD 189733b by Hubble and the Spitzer Space Telescope also detected water vapor and methane on that planet. But, by itself, these discoveries are not chemical proof of extraterrestrial life. Carbon dioxide in the atmosphere of an exoplanet is not unexpected. Earth's early atmosphere consisted largely of out-gassing of volcanoes: H2O, CO2, SO2, CO, S2, Cl2, N2, H2 and NH3 and CH4 -- not a particularly attractive brew for the emergence of life on our planet three billion years ago. But it seems to have been enough. The apparent fact that there is no life on Mars, however, does not entail that there is not life elsewhere in the cosmos. In early March 2009, NASA successfully launched the Kepler Mission into an orbit around the sun. This spacecraft will search for Earth-size rocky planets outside of our solar system in habitable zones orbiting stars at a distance where liquid water might potentially be found. Kepler will focus on the star-rich area of the sky in the constellations Cygnus and Lyra. Over the next six years it will measure variations in the brightness of more than 100,000 stars, searching for slight periodic dimming in a star's light output that may evidence an orbiting planet. ------- The suspicion of life on Mars was supported by the stream beds (water and lava), and frozen water ice at the poles. So there might be CO2 or hydrogen or nitrogen and other gases there as well.There's life there, but not native to Mars. NASA sent up a car to Mars to take some pictures. There's some bacteria that made it through the sterilization process. So that's the life. It survives on grease in the machine. The grease never gets quite cold enough to kill the bacteria riding in it; however, it's cold enough that their life processes are rather slowed down.
Digital fourier analyzer?
digital fourier analyzer analyses the signals in the form of fast fourier transform.
What are Joseph Fourier's works?
Fourier series and the Fourier transform
What are the uses of spectrum analyzer?
n analog spectrum analyzer \An analog spectrum analyzer uses either a variable band-pass filter whose mid-frequency is automatically tuned (shifted, swept) through the range of frequencies of which the spectrum is to be measured or a superheterodyne receiver where the local oscillator is swept through a range of frequencies. A digital spectrum analyzer computes the discrete Fourier transform (DFT), a mathematical process that transforms a waveform into the components of its frequency spectrum
Why was Joseph Fourier famous?
Joseph Fourier was the French mathematician and physicist after whom Fourier Series, Fourier's Law, and the Fourier Transform were named. He is commonly credited with discovering the greenhouse effect.
How do you find the inverse Fourier transform from Fourier series coefficients?
no
What is the difference between Dry chemistry analyzer and Chemistry analyzer?
The difference between dry chemistry analyzer and the chemistry analyzer is the reagents used.
What did Joseph fourier discover?
Joseph Fourier is a French mathematician and physicist. Fourier is generally credited with the discovery of the greenhouse effect.
What is the difference between fourier series and discrete fourier transform?
Fourier series is the sum of sinusoids representing the given function which has to be analysed whereas discrete fourier transform is a function which we get when summation is done.
What is the difference between discrete fourier transform and fast fourier transform?
discrete fourier transformer uses digital signals whereas the fast fourier transform uses both analog and digital.
How can a composite signal be decomposed into its individual frequencies?
Fourier analysis Frequency-domain graphs
Why you use fast fourier transform?
The fast fourier transform, which was invented by Tukey, significantly improves the speed of computation of discrete fourier transform.
How is spectrum analyzer operated?
How is spectrum analyzer operated?
