|
Radio Astronomy
"The first observations of cosmic radio emission were made by the American
engineer Karl G. Jansky in 1932, while studying thunderstorm radio disturbances at a frequency of 20.5 MHz (14.6 m). He discovered radio emission of unknown origin, which varied within a 24-hour period. Later he identified the source of this radiation to be in the direction of the centre of our Galaxy. From: http://encyclozine.com/science/astronomy/radio I understand that the frequency "varied within a 24-hour period". It is the "diurnal effect". And what about the 365 days period (annual effect)? S* |
Radio Astronomy
On Mon, 07 Nov 2011 10:14:14 +0100, Szczepan Bialek rearranged some
electrons to say: "The first observations of cosmic radio emission were made by the American engineer Karl G. Jansky in 1932, while studying thunderstorm radio disturbances at a frequency of 20.5 MHz (14.6 m). He discovered radio emission of unknown origin, which varied within a 24-hour period. Later he identified the source of this radiation to be in the direction of the centre of our Galaxy. From: http://encyclozine.com/science/astronomy/radio I understand that the frequency "varied within a 24-hour period". It is the "diurnal effect". And what about the 365 days period (annual effect)? S* It is not the frequency that changed, but the intensity. And not a 24 hour period, but 23 hours, 56 minutes, thus proving that the noise was not generated or varied by the earth's rotation. http://www.enotes.com/karl-jansky-reference/karl-jansky |
Quote:
So if the distant transmitter is an FM broadcast station you will hear a brief burst of audio from that station. If you are listening on an amateur radio band you will hear a brief exchange between two stations either in audio (SSB probably) or in Morse code (maybe high speed) or in a data transmission format. No sounds of the universe, just ordinary radio sounds but over an unusually long distance and a little spooky cos of the doppler and ionization distortion. depending upon the frequency in use and the 'strength' of the ionization caused by the meteor the duration of the reflection path can be long enough for a complete real time over-over QSO to take place where callsigns and signal strength reports can be exchanged between the two amateur radio stations. The 50MHz and 144MHz allocations are good places to listen for this. |
Radio Astronomy
" napisał w wiadomości ... On Mon, 07 Nov 2011 10:14:14 +0100, Szczepan Bialek rearranged some electrons to say: "The first observations of cosmic radio emission were made by the American engineer Karl G. Jansky in 1932, while studying thunderstorm radio disturbances at a frequency of 20.5 MHz (14.6 m). He discovered radio emission of unknown origin, which varied within a 24-hour period. Later he identified the source of this radiation to be in the direction of the centre of our Galaxy. From: http://encyclozine.com/science/astronomy/radio I understand that the frequency "varied within a 24-hour period". It is the "diurnal effect". And what about the 365 days period (annual effect)? S* It is not the frequency that changed, but the intensity. And not a 24 hour period, but 23 hours, 56 minutes, thus proving that the noise was not generated or varied by the earth's rotation. http://www.enotes.com/karl-jansky-reference/karl-jansky Yes. "His" transmitter "produced" many frequencies. But Karl G. Jansky was the pioneer in Radio Astronomy. Now are the spacecrafts. They use the two frequencies. I have found the link: http://chaos.swarthmore.edu/courses/...er_Anomaly.pdf ""It is also possible to infer the position in the sky of a spacecraft from the Doppler data. This is accomplished by examining the diurnal variation imparted to the Doppler shift by the Earth's rotation. As the ground station rotates underneath a spacecraft, the Doppler shift is modulated by a sinusoid." Probably in this paper is also the answer for my question: "And what about the 365 days period (annual effect)? Unfortunately I am not an expert in radio. Do you know the answer? S* |
Radio Astronomy
Szczepan Bialek wrote:
Probably in this paper is also the answer for my question: "And what about the 365 days period (annual effect)? Unfortunately I am not an expert in radio. Do you know the answer? S* Why are you so obsessed by this question? |
Radio Astronomy
On 11/7/2011 12:50 PM, Rob wrote:
Szczepan wrote: Probably in this paper is also the answer for my question: "And what about the 365 days period (annual effect)? Unfortunately I am not an expert in radio. Do you know the answer? S* Why are you so obsessed by this question? He's not. He's just obsessed. He loves to ask questio0ns, get answers, and then tell all of us that any science newer than 100 or 150 years old is incorrect. Even when the scientist in question changed his original theory due to newer and better evidence. It will happen. Just wait a bit. tom K0TAR |
Radio Astronomy
Uzytkownik "Rob" napisal w wiadomosci ... Szczepan Bialek wrote: Probably in this paper is also the answer for my question: "And what about the 365 days period (annual effect)? Unfortunately I am not an expert in radio. Do you know the answer? S* Why are you so obsessed by this question? Once mo ""In 1818 Arago found that the refraction of a prism for star light was the same for light incident in the direction of the earth's orbital velocity v as for that coming in the opposite direction. This unexpected null result was explained that same year by Fresnel's ether-dray theory, which assumed partial ether entrainment in transparent media by an amount depending upon the first power of v." From: http://www.3rd1000.com/chronoatoms.htm Today's spectrograph astronomers assume that the effect is not null. It seems to me that today's astronomers are wrong because in physics are still null result. So I am looking for the result from communication with the spacecraft. S* |
Radio Astronomy
Uzytkownik "tom" napisal w wiadomosci . net... On 11/7/2011 12:50 PM, Rob wrote: Szczepan wrote: Probably in this paper is also the answer for my question: "And what about the 365 days period (annual effect)? Unfortunately I am not an expert in radio. Do you know the answer? S* Why are you so obsessed by this question? He's not. He's just obsessed. He loves to ask questio0ns, get answers, and then tell all of us that any science newer than 100 or 150 years old is incorrect. Even when the scientist in question changed his original theory due to newer and better evidence. In each textbook is wrote that we can detect the angular motion of the Earth but the orbital not. It will happen. Just wait a bit. To you know the best evidence (the frequency variation from the spacecraft in the annual period)? S* |
Radio Astronomy
On 11/8/2011 2:10 AM, Szczepan Bialek wrote:
Uzytkownik napisal w wiadomosci ... Szczepan wrote: Probably in this paper is also the answer for my question: "And what about the 365 days period (annual effect)? Unfortunately I am not an expert in radio. Do you know the answer? S* Why are you so obsessed by this question? Once mo ""In 1818 Arago found that the refraction of a prism for star light was the same for light incident in the direction of the earth's orbital velocity v as for that coming in the opposite direction. This unexpected null result was explained that same year by Fresnel's ether-dray theory, which assumed partial ether entrainment in transparent media by an amount depending upon the first power of v." From: http://www.3rd1000.com/chronoatoms.htm Today's spectrograph astronomers assume that the effect is not null. It seems to me that today's astronomers are wrong because in physics are still null result. So I am looking for the result from communication with the spacecraft. S* Like I said. He doesn't like new results. Ever. And if you provide evidence that he doesn't like, such as spacecraft comm results that will likely not be what he likes, he will dispute it and point back to the deprecated experiments. It never ends. He is the ultimate troll. Ok, the ultimate troll isn't him, it's another that hasn't shown up here lately, but he's very close. tom K0TAR |
Radio Astronomy
"tom" napisal w wiadomosci . net... On 11/8/2011 2:10 AM, Szczepan Bialek wrote: Uzytkownik napisal w wiadomosci ... Szczepan wrote: Probably in this paper is also the answer for my question: "And what about the 365 days period (annual effect)? Unfortunately I am not an expert in radio. Do you know the answer? S* Why are you so obsessed by this question? Once mo ""In 1818 Arago found that the refraction of a prism for star light was the same for light incident in the direction of the earth's orbital velocity v as for that coming in the opposite direction. This unexpected null result was explained that same year by Fresnel's ether-dray theory, which assumed partial ether entrainment in transparent media by an amount depending upon the first power of v." From: http://www.3rd1000.com/chronoatoms.htm Today's spectrograph astronomers assume that the effect is not null. It seems to me that today's astronomers are wrong because in physics are still null result. So I am looking for the result from communication with the spacecraft. S* Like I said. He doesn't like new results. Ever. I am looking for the new result. Astronomers ASSUME. I do not know why. And if you provide evidence that he doesn't like, such as spacecraft comm results that will likely not be what he likes, he will dispute it and point back to the deprecated experiments. In today's physics is opinion that we can detect the angular motion (Sagnac effect) but it is impossible to detect the linear motion. Who and when deprecated the famous null result? S* |
Radio Astronomy
Once mo ""In 1818 Arago found that the refraction of a prism for star light was the same for light incident in the direction of the earth's orbital velocity v as for that coming in the opposite direction. This unexpected null result was explained that same year by Fresnel's ether-dray theory, which assumed partial ether entrainment in transparent media by an amount depending upon the first power of v." From: http://www.3rd1000.com/chronoatoms.htm Today's spectrograph astronomers assume that the effect is not null. It seems to me that today's astronomers are wrong because in physics are still null result. So I am looking for the result from communication with the spacecraft. S* Earth's rotation is about 465.1 m/s Say the average frequency of visible light is 500THz doppler shift is (Vr/C)*F = (465/ 3 * 10^8)*500 * 10^12 = 7.75 10^8Hz So to see the shift you will need to be able to observe your light frequency to an accuracy of about 0.00015%. Which would have been impossible for Arago. Of course the above figures are only true for light coming directly at the observer ie on the horizon, so for other angles there is a Cos Theta term to reduce the effect even more (to zero directly overhead). Jeff |
Radio Astronomy
"Jeff" napisal w wiadomosci ... Once mo ""In 1818 Arago found that the refraction of a prism for star light was the same for light incident in the direction of the earth's orbital velocity v as for that coming in the opposite direction. This unexpected null result was explained that same year by Fresnel's ether-dray theory, which assumed partial ether entrainment in transparent media by an amount depending upon the first power of v." From: http://www.3rd1000.com/chronoatoms.htm Today's spectrograph astronomers assume that the effect is not null. It seems to me that today's astronomers are wrong because in physics are still null result. So I am looking for the result from communication with the spacecraft. S* Earth's rotation is about 465.1 m/s Say the average frequency of visible light is 500THz doppler shift is (Vr/C)*F = (465/ 3 * 10^8)*500 * 10^12 = 7.75 10^8Hz So to see the shift you will need to be able to observe your light frequency to an accuracy of about 0.00015%. Which would have been impossible for Arago. "In 1818 Arago found that the refraction of a prism for star light was the same for light incident in the direction of the earth's orbital velocity v as for that coming in the opposite direction". The orbital speed is about 30 km/s. Todays radio methods are adequate for 0.5 and for 30. Of course the above figures are only true for light coming directly at the observer ie on the horizon, so for other angles there is a Cos Theta term to reduce the effect even more (to zero directly overhead). The rotational speed was too small for everybody till 1925. In this year the Michelson and Gale detected the Earth's rotation.. But nobody detect the orbital speed. The same is with the spacecrafts. The diurnal effect is confirmed. I am looking for the annual effect. S* S* |
Radio Astronomy
On 11/7/2011 1:14 AM, Szczepan Bialek wrote:
"The first observations of cosmic radio emission were made by the American engineer Karl G. Jansky in 1932, while studying thunderstorm radio disturbances at a frequency of 20.5 MHz (14.6 m). He discovered radio emission of unknown origin, which varied within a 24-hour period. Later he identified the source of this radiation to be in the direction of the centre of our Galaxy. From: http://encyclozine.com/science/astronomy/radio I understand that the frequency "varied within a 24-hour period". It is the "diurnal effect". And what about the 365 days period (annual effect)? S* You mean when earth is generally heading "towards" the galactic center vs when earth is heading "away" from the galactic center? People doing deep space navigation deal with this all the time, since navigation is done by measuring the frequency of the received signal from the spacecraft. There's nothing special about it. spacecraft on some heliocentric trajectory, Earth on a different heliocentric trajectory. Measure frequency shift, they use to determine spacecraft trajectory by applying (mostly) Newtonian physics (you do have to use relativistic corrections to get the last gnat's eyelash of precision). Since you only get to measure in one direction, you have to make assumptions about what's going on in the other directions, (e.g. cross range), which can lead to disasters (Mars Climate Orbiter, most recently). You can do various forms of VLBI and DeltaDOR to get some cross range information, but nothing as good as what you're getting for range (where velocity and range are measured to mm/s and cm sorts of accuracy) |
Radio Astronomy
"Jim Lux" napisal w wiadomosci ... On 11/7/2011 1:14 AM, Szczepan Bialek wrote: "The first observations of cosmic radio emission were made by the American engineer Karl G. Jansky in 1932, while studying thunderstorm radio disturbances at a frequency of 20.5 MHz (14.6 m). He discovered radio emission of unknown origin, which varied within a 24-hour period. Later he identified the source of this radiation to be in the direction of the centre of our Galaxy. From: http://encyclozine.com/science/astronomy/radio I understand that the frequency "varied within a 24-hour period". It is the "diurnal effect". And what about the 365 days period (annual effect)? S* You mean when earth is generally heading "towards" the galactic center vs when earth is heading "away" from the galactic center? Yes. But on the Earth orbit are places when this speed is 0.5 km/s (only rotation) or 30 km/s. (orbital speed). People doing deep space navigation deal with this all the time, since navigation is done by measuring the frequency of the received signal from the spacecraft. There's nothing special about it. spacecraft on some heliocentric trajectory, Earth on a different heliocentric trajectory. Like the Earth and Mars. Measure frequency shift, they use to determine spacecraft trajectory by applying (mostly) Newtonian physics (you do have to use relativistic corrections to get the last gnat's eyelash of precision). They confirm the diurnal changings in the frequency. But what with the annual? Since you only get to measure in one direction, you have to make assumptions about what's going on in the other directions, (e.g. cross range), which can lead to disasters (Mars Climate Orbiter, most recently). You can do various forms of VLBI and DeltaDOR to get some cross range information, but nothing as good as what you're getting for range (where velocity and range are measured to mm/s and cm sorts of accuracy) Naw are the spacecraft at distances almost like stars. They are not on heliocentric trajectory. So I repeat my question: " I have found the link: http://chaos.swarthmore.edu/courses/...er_Anomaly.pdf ""It is also possible to infer the position in the sky of a spacecraft from the Doppler data. This is accomplished by examining the diurnal variation imparted to the Doppler shift by the Earth's rotation. As the ground station rotates underneath a spacecraft, the Doppler shift is modulated by a sinusoid." Here they confirm the diurnal variation in the frequency. Probably in this paper is also the answer for my question: "And what about the 365 days period (annual variation in the frequency)? Unfortunately I am not an expert in radio. Do you know the answer? S* |
Radio Astronomy
On 11/15/2011 12:56 AM, Szczepan Bialek wrote:
"Jim napisal w wiadomosci n You mean when earth is generally heading "towards" the galactic center vs when earth is heading "away" from the galactic center? Yes. But on the Earth orbit are places when this speed is 0.5 km/s (only rotation) or 30 km/s. (orbital speed). People doing deep space navigation deal with this all the time, since navigation is done by measuring the frequency of the received signal from the spacecraft. There's nothing special about it. spacecraft on some heliocentric trajectory, Earth on a different heliocentric trajectory. Like the Earth and Mars. Yes, and, for instance, they measure the Doppler shift in the signals radiated from spacecraft/rovers in orbit/on the surface of Mars as they arrive at earth. As expected, the Doppler has several components: one from the rotation of Earth, one from the rotation of Mars (for a surface asset), and one from the relative motion of Mars and Earth (which is periodic with about a 2 year, 2 month period) No surprises, nothing unusual. In fact, *tiny* variations in the Doppler are used to compute the orbit around planets, and from that, infer the internal structure of the planet. Juno is going to Jupiter right now to do this, and the Doppler will be measured with a precision of about 1 part in 1E15 (measured over 100-1000 seconds). Measure frequency shift, they use to determine spacecraft trajectory by applying (mostly) Newtonian physics (you do have to use relativistic corrections to get the last gnat's eyelash of precision). They confirm the diurnal changings in the frequency. But what with the annual? All changes in frequency, of course. Load up the SPICE kernels, run the numerical integration, and the expected frequency pops out. Since you only get to measure in one direction, you have to make assumptions about what's going on in the other directions, (e.g. cross range), which can lead to disasters (Mars Climate Orbiter, most recently). You can do various forms of VLBI and DeltaDOR to get some cross range information, but nothing as good as what you're getting for range (where velocity and range are measured to mm/s and cm sorts of accuracy) Naw are the spacecraft at distances almost like stars. They are not on heliocentric trajectory. All spacecraft that humans have launched are on some form of either planetary centric or heliocentric trajectory or a combination of both. In any case, they are computable (viz. Gauss) and measureable. So I repeat my question: " I have found the link: http://chaos.swarthmore.edu/courses/...er_Anomaly.pdf ""It is also possible to infer the position in the sky of a spacecraft from the Doppler data. This is accomplished by examining the diurnal variation imparted to the Doppler shift by the Earth's rotation. As the ground station rotates underneath a spacecraft, the Doppler shift is modulated by a sinusoid." That's somewhat of an over simplification, but it's essentially true. The paper describes the technique used to measure the frequency.. A signal is generated on the ground at 2.11 GHz, locked to a hydrogen maser. that signal is radiated to the spacecraft, which uses a phase locked loop to track it. The spacecraft sends back a signal with a frequency/phase ratio of exactly 240/221 (i.e. about 2.29 GHz) which is received on earth and compared with the same hydrogen maser. Here they confirm the diurnal variation in the frequency. Probably in this paper is also the answer for my question: "And what about the 365 days period (annual variation in the frequency)? Unfortunately I am not an expert in radio. Do you know the answer? Do you want to know the magnitude of the shift? Earth's orbital velocity is about 30km/s, so the fractional frequency change is 1 part in 1E4 (100ppm). That's huge compared to, for example, the change due to the oscillator frequency aging. Considering that for deep space navigation, frequencies are regularly measured these days to parts in 1E12, this is something they deal with on a day to day basis at the Deep Space Network. if you want more details, take a look at equations (3) through (6) on page 11-12 of the 50 page paper you cited, which gives a nice detailed explanation of all the factors they are taking into account. And, they nicely note how you can use the models to implement theories of gravity other than general relativity. equation 4 describes the light time (which ties to doppler measurement) and includes the relativistic corrections as well. they take into account things you haven't mentioned such as changes in the earth orientation (precession, for instance), changes in earth rotation rate. "In summary, this dynamical model accounts for a number of post-Newtonian perturbations in the motions of the planets, the Moon, and spacecraft. Light propagation is correct to order c^-2. The equations of motion of extended celestial bodies are valid to order c^-4. Indeed, this dynamical model has been good enough to perform tests of general relativity @28,51,52#." I'd comment that if you read and understand the entire paper, you're well on your way to really knowing how we do deep space navigation and the myriad things that have an effect and must be taken into account. They also have a VERY complete discussion of numerical computation effects. They also do mention an annual sinusoid (not accounted for by simple orbital motion) of 1.6E-8 cm/s^2... (about 0.012 Hz at 2.29GHz) (page 37) which they attribute to small problems in their modeling of the solar system that are normally masked by other noise sources, but because Pioneer makes such a good detector, you can find it. I'll note that the anomaly identified in the paper has since been analyzed extensively, and as I recall, once you take into account the thermal radiation pressure with sufficient accuracy, you can account for it. (there has been a substantial improvement in computational and modeling capability in the last 10 years, since that paper was published) After all, the paper says "Further experiment and analysis is obviously needed to resolve this problem." |
Radio Astronomy
"Jim Lux" napisal w wiadomosci ... On 11/15/2011 12:56 AM, Szczepan Bialek wrote: "Jim napisal w wiadomosci n You mean when earth is generally heading "towards" the galactic center vs when earth is heading "away" from the galactic center? Yes. But on the Earth orbit are places when this speed is 0.5 km/s (only rotation) or 30 km/s. (orbital speed). People doing deep space navigation deal with this all the time, since navigation is done by measuring the frequency of the received signal from the spacecraft. There's nothing special about it. spacecraft on some heliocentric trajectory, Earth on a different heliocentric trajectory. Like the Earth and Mars. Yes, and, for instance, they measure the Doppler shift in the signals radiated from spacecraft/rovers in orbit/on the surface of Mars as they arrive at earth. Do they published the results? As expected, the Doppler has several components: one from the rotation of Earth, one from the rotation of Mars (for a surface asset), and one from the relative motion of Mars and Earth (which is periodic with about a 2 year, 2 month period) I am asking about "one from the relative motion of Mars and Earth " No surprises, nothing unusual. In fact, *tiny* variations in the Doppler are used to compute the orbit around planets, and from that, infer the internal structure of the planet. Juno is going to Jupiter right now to do this, and the Doppler will be measured with a precision of about 1 part in 1E15 (measured over 100-1000 seconds). Measure frequency shift, they use to determine spacecraft trajectory by applying (mostly) Newtonian physics (you do have to use relativistic corrections to get the last gnat's eyelash of precision). They confirm the diurnal changings in the frequency. But what with the annual? All changes in frequency, of course. Load up the SPICE kernels, run the numerical integration, and the expected frequency pops out. I am interested only in the measured results. Since you only get to measure in one direction, you have to make assumptions about what's going on in the other directions, (e.g. cross range), which can lead to disasters (Mars Climate Orbiter, most recently). You can do various forms of VLBI and DeltaDOR to get some cross range information, but nothing as good as what you're getting for range (where velocity and range are measured to mm/s and cm sorts of accuracy) Naw are the spacecraft at distances almost like stars. They are not on heliocentric trajectory. All spacecraft that humans have launched are on some form of either planetary centric or heliocentric trajectory or a combination of both. In any case, they are computable (viz. Gauss) and measureable. So I repeat my question: " I have found the link: http://chaos.swarthmore.edu/courses/...er_Anomaly.pdf ""It is also possible to infer the position in the sky of a spacecraft from the Doppler data. This is accomplished by examining the diurnal variation imparted to the Doppler shift by the Earth's rotation. As the ground station rotates underneath a spacecraft, the Doppler shift is modulated by a sinusoid." That's somewhat of an over simplification, but it's essentially true. The paper describes the technique used to measure the frequency.. A signal is generated on the ground at 2.11 GHz, locked to a hydrogen maser. that signal is radiated to the spacecraft, which uses a phase locked loop to track it. The spacecraft sends back a signal with a frequency/phase ratio of exactly 240/221 (i.e. about 2.29 GHz) which is received on earth and compared with the same hydrogen maser. Here they confirm the diurnal variation in the frequency. Probably in this paper is also the answer for my question: "And what about the 365 days period (annual variation in the frequency)? Unfortunately I am not an expert in radio. Do you know the answer? Do you want to know the magnitude of the shift? The measured value. Earth's orbital velocity is about 30km/s, so the fractional frequency change is 1 part in 1E4 (100ppm). That's huge compared to, for example, the change due to the oscillator frequency aging. Considering that for deep space navigation, frequencies are regularly measured these days to parts in 1E12, this is something they deal with on a day to day basis at the Deep Space Network. if you want more details, take a look at equations (3) through (6) on page 11-12 of the 50 page paper you cited, which gives a nice detailed explanation of all the factors they are taking into account. And, they nicely note how you can use the models to implement theories of gravity other than general relativity. equation 4 describes the light time (which ties to doppler measurement) and includes the relativistic corrections as well. they take into account things you haven't mentioned such as changes in the earth orientation (precession, for instance), changes in earth rotation rate. "In summary, this dynamical model accounts for a number of post-Newtonian perturbations in the motions of the planets, the Moon, and spacecraft. Light propagation is correct to order c^-2. The equations of motion of extended celestial bodies are valid to order c^-4. Indeed, this dynamical model has been good enough to perform tests of general relativity @28,51,52#." I'd comment that if you read and understand the entire paper, you're well on your way to really knowing how we do deep space navigation and the myriad things that have an effect and must be taken into account. They also have a VERY complete discussion of numerical computation effects. They also do mention an annual sinusoid (not accounted for by simple orbital motion) of 1.6E-8 cm/s^2... (about 0.012 Hz at 2.29GHz) (page 37) which they attribute to small problems in their modeling of the solar system that are normally masked by other noise sources, but because Pioneer makes such a good detector, you can find it. They wrote (page 37): " Fig. 17, which shows the aP residuals from a value for aP of (7.7760.16)31028 cm/s2. The data was processed using ODP-SIGMA with a batch-sequential filter and smoothing algorithm. The solution for aP was obtained using 1-day batch sizes. Also shown are the maneuver times. At early times the annual term is largest. During Interval II, the interval of the large spin-rate change anomaly, coherent oscillation is lost. During Interval III the oscillation is smaller and begins to die" I "read the entire paper" but I do not and understand if the above "During Interval III the oscillation is smaller and begins to die" means that the annual variation in frequency die when the spacecraft was very far. I'll note that the anomaly identified in the paper has since been analyzed extensively, and as I recall, once you take into account the thermal radiation pressure with sufficient accuracy, you can account for it. (there has been a substantial improvement in computational and modeling capability in the last 10 years, since that paper was published) After all, the paper says "Further experiment and analysis is obviously needed to resolve this problem." I was ony trying to pick up if the annual variation in frequency take place or not. The reason is simply. The diurnal variation are in agreement with the Michelson-Gale experiment. The annuall should be null like the famous MM. S* |
Radio Astronomy
On 11/16/2011 10:57 AM, Szczepan Bialek wrote:
"Jim napisal w wiadomosci ... On 11/15/2011 12:56 AM, Szczepan Bialek wrote: "Jim napisal w wiadomosci n You mean when earth is generally heading "towards" the galactic center vs when earth is heading "away" from the galactic center? Yes. But on the Earth orbit are places when this speed is 0.5 km/s (only rotation) or 30 km/s. (orbital speed). People doing deep space navigation deal with this all the time, since navigation is done by measuring the frequency of the received signal from the spacecraft. There's nothing special about it. spacecraft on some heliocentric trajectory, Earth on a different heliocentric trajectory. Like the Earth and Mars. Yes, and, for instance, they measure the Doppler shift in the signals radiated from spacecraft/rovers in orbit/on the surface of Mars as they arrive at earth. Do they published the results? Sure.. Some are in that paper you cited. As expected, the Doppler has several components: one from the rotation of Earth, one from the rotation of Mars (for a surface asset), and one from the relative motion of Mars and Earth (which is periodic with about a 2 year, 2 month period) I am asking about "one from the relative motion of Mars and Earth " I imagine so, although I don't know where one get the data off hand. But they archive and publish pretty much everything that comes down along with all the radiometric data (doppler, phase, signal strength) in various and sundry mission data repositories. getting it in a convenient translated form might take some work. No surprises, nothing unusual. In fact, *tiny* variations in the Doppler are used to compute the orbit around planets, and from that, infer the internal structure of the planet. Juno is going to Jupiter right now to do this, and the Doppler will be measured with a precision of about 1 part in 1E15 (measured over 100-1000 seconds). Measure frequency shift, they use to determine spacecraft trajectory by applying (mostly) Newtonian physics (you do have to use relativistic corrections to get the last gnat's eyelash of precision). They confirm the diurnal changings in the frequency. But what with the annual? All changes in frequency, of course. Load up the SPICE kernels, run the numerical integration, and the expected frequency pops out. I am interested only in the measured results. Look for what's called Level 0 telemetry data from your missions of choice. Here they confirm the diurnal variation in the frequency. Probably in this paper is also the answer for my question: "And what about the 365 days period (annual variation in the frequency)? Unfortunately I am not an expert in radio. Do you know the answer? Do you want to know the magnitude of the shift? The measured value. They wrote (page 37): " Fig. 17, which shows the aP residuals from a value for aP of (7.7760.16)31028 cm/s2. The data was processed using ODP-SIGMA with a batch-sequential filter and smoothing algorithm. The solution for aP was obtained using 1-day batch sizes. Also shown are the maneuver times. At early times the annual term is largest. During Interval II, the interval of the large spin-rate change anomaly, coherent oscillation is lost. During Interval III the oscillation is smaller and begins to die" I "read the entire paper" but I do not and understand if the above "During Interval III the oscillation is smaller and begins to die" means that the annual variation in frequency die when the spacecraft was very far. Dunno.. I was ony trying to pick up if the annual variation in frequency take place or not. The "anomaly" variation or the "variation due to earth in its orbit"? I suppose the answer to both is "yes" The reason is simply. The diurnal variation are in agreement with the Michelson-Gale experiment. The annuall should be null like the famous MM. If you need raw data, you'll need to look for it. I'd suggest starting with the Planetary Data System http://pds.jpl.nasa.gov/ Maybe the stuff at NAIF (Navigation and Ancillary Information Facility) might help. There's a lot of stuff out there, but, for instance, I ran across the raw Radio Occultation Original Data Records from Ulysses. It has a description including: "These data are obtained from the Radio Science Support group at JPL. They consist of time-ordered, high-time resolution Doppler data from special radio science receivers (so-called 'open loop' data)." There's a lot more description online and that's probably not a data set you're looking for, but the data is out there, if you're willing to go digging through it. I doubt anyone is going to give you exactly what you're looking for, though. You'll have to do some conversion, and you'll need to know a fair amount about how all the tracking systems work, but that's all published. You might start with the DSN 810-005 online document (google for it).. That will tell you how they record the data and the format. A more recent data set is from MRO "This data set contains archival raw, partially processed, and ancillary/supporting radio science data acquired during the Mars Reconnaissance Orbiter (MRO) mission. The radio observations were carried out using the MRO spacecraft and Earth-based receiving stations of the NASA Deep Space Network (DSN). The data set was designed primarily to support generation of high-resolution gravity field models for Mars and secondarily for estimating density and structure of the Mars atmosphere. Of most interest are likely to be the Orbit Data Files and Radio Science Receiver files in the ODF and RSR directories, respectively, which provided the raw input to gravity and atmospheric investigations, as well as the ionospheric and tropospheric media calibration files in the ION and TRO directories, respectively." http://starbrite.jpl.nasa.gov/pds/vi...SS-1-MAGR-V1.0 Among the stuff in that particular data set is: " The ODF is a compressed version of the TNF. It contains the most important information (range, Doppler and frequency ramps) needed by spacecraft investigators, and investigators interested in determining gravity fields. Each ODF is accompanied by a full PDS label which describes both the content and format of the associated file. ODF data fields include: Narrowband spacecraft VLBI, Doppler mode (cycles) Narrowband spacecraft VLBI, phase mode (cycles) Narrowband quasar VLBI, Doppler mode (cycles) Narrowband quasar VLBI, phase mode (cycles) Wideband spacecraft VLBI (nanoseconds) Wideband quasar VLBI (nanoseconds) One-way Doppler (Hertz) Two-way Doppler (Hertz) Three-way Doppler (Hertz) One-way total count phase (cycles) Two-way total count phase (cycles) Three-way total count phase (cycles) PRA planetary operational discrete spectrum range (range units) SRA planetary operational discrete spectrum range (range units) RE(GSTDN) range (nanoseconds) Azimuth angle (degrees) Elevation angle (degrees) Hour angle (degrees) Declination angle (degrees) " So there you have all the VLBI and doppler info you're looking for. The actual data files are at http://pds-geosciences.wustl.edu/mro...v1/mrors_0xxx/ (There's a link at the PDS catalog entry) There's documentation on the format of the ODF files, and I see that they actually give you Doppler and range observables, rather than raw counts, which is nice. Knock yourself out... |
Radio Astronomy
"Jim Lux" napisal w wiadomosci ... On 11/16/2011 10:57 AM, Szczepan Bialek wrote: "Jim napisal w wiadomosci ... On 11/15/2011 12:56 AM, Szczepan Bialek wrote: "Jim napisal w wiadomosci n You mean when earth is generally heading "towards" the galactic center vs when earth is heading "away" from the galactic center? Yes. But on the Earth orbit are places when this speed is 0.5 km/s (only rotation) or 30 km/s. (orbital speed). People doing deep space navigation deal with this all the time, since navigation is done by measuring the frequency of the received signal from the spacecraft. There's nothing special about it. spacecraft on some heliocentric trajectory, Earth on a different heliocentric trajectory. Like the Earth and Mars. Yes, and, for instance, they measure the Doppler shift in the signals radiated from spacecraft/rovers in orbit/on the surface of Mars as they arrive at earth. Do they published the results? Sure.. Some are in that paper you cited. As expected, the Doppler has several components: one from the rotation of Earth, one from the rotation of Mars (for a surface asset), and one from the relative motion of Mars and Earth (which is periodic with about a 2 year, 2 month period) I am asking about "one from the relative motion of Mars and Earth " I imagine so, although I don't know where one get the data off hand. But they archive and publish pretty much everything that comes down along with all the radiometric data (doppler, phase, signal strength) in various and sundry mission data repositories. getting it in a convenient translated form might take some work. I am not able to do any work in the data. I will be waiting as somebody do it. No surprises, nothing unusual. In fact, *tiny* variations in the Doppler are used to compute the orbit around planets, and from that, infer the internal structure of the planet. Juno is going to Jupiter right now to do this, and the Doppler will be measured with a precision of about 1 part in 1E15 (measured over 100-1000 seconds). Measure frequency shift, they use to determine spacecraft trajectory by applying (mostly) Newtonian physics (you do have to use relativistic corrections to get the last gnat's eyelash of precision). They confirm the diurnal changings in the frequency. But what with the annual? All changes in frequency, of course. Load up the SPICE kernels, run the numerical integration, and the expected frequency pops out. I am interested only in the measured results. Look for what's called Level 0 telemetry data from your missions of choice. Here they confirm the diurnal variation in the frequency. Probably in this paper is also the answer for my question: "And what about the 365 days period (annual variation in the frequency)? Unfortunately I am not an expert in radio. Do you know the answer? Do you want to know the magnitude of the shift? The measured value. They wrote (page 37): " Fig. 17, which shows the aP residuals from a value for aP of (7.7760.16)31028 cm/s2. The data was processed using ODP-SIGMA with a batch-sequential filter and smoothing algorithm. The solution for aP was obtained using 1-day batch sizes. Also shown are the maneuver times. At early times the annual term is largest. During Interval II, the interval of the large spin-rate change anomaly, coherent oscillation is lost. During Interval III the oscillation is smaller and begins to die" I "read the entire paper" but I do not and understand if the above "During Interval III the oscillation is smaller and begins to die" means that the annual variation in frequency die when the spacecraft was very far. Dunno.. I was ony trying to pick up if the annual variation in frequency take place or not. The "anomaly" variation or the "variation due to earth in its orbit"? I suppose the answer to both is "yes" But it is not clearly stated. The reason is simply. The diurnal variation are in agreement with the Michelson-Gale experiment. The annuall should be null like the famous MM. If you need raw data, you'll need to look for it. I'd suggest starting with the Planetary Data System http://pds.jpl.nasa.gov/ Maybe the stuff at NAIF (Navigation and Ancillary Information Facility) might help. There's a lot of stuff out there, but, for instance, I ran across the raw Radio Occultation Original Data Records from Ulysses. It has a description including: "These data are obtained from the Radio Science Support group at JPL. They consist of time-ordered, high-time resolution Doppler data from special radio science receivers (so-called 'open loop' data)." There's a lot more description online and that's probably not a data set you're looking for, but the data is out there, if you're willing to go digging through it. I doubt anyone is going to give you exactly what you're looking for, though. They confirm the diurnal oscilations. They do not mention the annual. So I assume that the annual are null. You'll have to do some conversion, and you'll need to know a fair amount about how all the tracking systems work, but that's all published. You might start with the DSN 810-005 online document (google for it).. That will tell you how they record the data and the format. A more recent data set is from MRO "This data set contains archival raw, partially processed, and ancillary/supporting radio science data acquired during the Mars Reconnaissance Orbiter (MRO) mission. The radio observations were carried out using the MRO spacecraft and Earth-based receiving stations of the NASA Deep Space Network (DSN). The data set was designed primarily to support generation of high-resolution gravity field models for Mars and secondarily for estimating density and structure of the Mars atmosphere. Of most interest are likely to be the Orbit Data Files and Radio Science Receiver files in the ODF and RSR directories, respectively, which provided the raw input to gravity and atmospheric investigations, as well as the ionospheric and tropospheric media calibration files in the ION and TRO directories, respectively." http://starbrite.jpl.nasa.gov/pds/vi...SS-1-MAGR-V1.0 Among the stuff in that particular data set is: " The ODF is a compressed version of the TNF. It contains the most important information (range, Doppler and frequency ramps) needed by spacecraft investigators, and investigators interested in determining gravity fields. Each ODF is accompanied by a full PDS label which describes both the content and format of the associated file. ODF data fields include: Narrowband spacecraft VLBI, Doppler mode (cycles) Narrowband spacecraft VLBI, phase mode (cycles) Narrowband quasar VLBI, Doppler mode (cycles) Narrowband quasar VLBI, phase mode (cycles) Wideband spacecraft VLBI (nanoseconds) Wideband quasar VLBI (nanoseconds) One-way Doppler (Hertz) Two-way Doppler (Hertz) Three-way Doppler (Hertz) One-way total count phase (cycles) Two-way total count phase (cycles) Three-way total count phase (cycles) PRA planetary operational discrete spectrum range (range units) SRA planetary operational discrete spectrum range (range units) RE(GSTDN) range (nanoseconds) Azimuth angle (degrees) Elevation angle (degrees) Hour angle (degrees) Declination angle (degrees) " So there you have all the VLBI and doppler info you're looking for. The actual data files are at http://pds-geosciences.wustl.edu/mro...v1/mrors_0xxx/ (There's a link at the PDS catalog entry) There's documentation on the format of the ODF files, and I see that they actually give you Doppler and range observables, rather than raw counts, which is nice. The answer I am loking for is not important for me. I have come accros an information that astronomers add the orbital speed of the Earth to the radial speed of stars measured with the spectrographic method. The radio method are the same like the spectrography. But it contradicts MMX. So I am trying to clear it. S* |
Radio Astronomy
On 11/17/2011 9:29 AM, Szczepan Bialek wrote:
"Jim napisal w wiadomosci I imagine so, although I don't know where one get the data off hand. But they archive and publish pretty much everything that comes down along with all the radiometric data (doppler, phase, signal strength) in various and sundry mission data repositories. getting it in a convenient translated form might take some work. I am not able to do any work in the data. I will be waiting as somebody do it. Giant snip of places where you can find the data you asked about The answer I am loking for is not important for me. I have come accros an information that astronomers add the orbital speed of the Earth to the radial speed of stars measured with the spectrographic method. The radio method are the same like the spectrography. But it contradicts MMX. So I am trying to clear it. Uh.. no.. you have a theory or question, but aren't willing or able to do the work (or find someone else to do the work) to actual resolve the issue. Tons of data Tons of analysis out there You've got a question, you need to answer it. (or, just wait until someone else happens to answer it for you...) |
Radio Astronomy
On 11/17/2011 2:15 PM, Jim Lux wrote:
snip nonsense from someone who has never produced anything but Uh.. no.. you have a theory or question, but aren't willing or able to do the work (or find someone else to do the work) to actual resolve the issue. Tons of data Tons of analysis out there You've got a question, you need to answer it. (or, just wait until someone else happens to answer it for you...) Nice. Succinct and to the point. Unfortunately wasted on him. tom K0TAR |
Radio Astronomy
"tom" napisal w wiadomosci . net... On 11/17/2011 2:15 PM, Jim Lux wrote: snip nonsense from someone who has never produced anything but Uh.. no.. you have a theory or question, but aren't willing or able to do the work (or find someone else to do the work) to actual resolve the issue. Tons of data Tons of analysis out there You've got a question, you need to answer it. (or, just wait until someone else happens to answer it for you...) Nice. Succinct and to the point. Unfortunately wasted on him. " Some people know the Doppler effects components: "the Doppler has several components: one from the rotation of Earth, one from the rotation of Mars (for a surface asset), and one from the relative motion of Mars and Earth" I am looking for information about relative motion of "Mars and Earth" and "Earth and Pioneer". Have you such? S* |
Radio Astronomy
"Jim Lux" napisal w wiadomosci ... On 11/17/2011 9:29 AM, Szczepan Bialek wrote: "Jim napisal w wiadomosci I imagine so, although I don't know where one get the data off hand. But they archive and publish pretty much everything that comes down along with all the radiometric data (doppler, phase, signal strength) in various and sundry mission data repositories. getting it in a convenient translated form might take some work. I am not able to do any work in the data. I will be waiting as somebody do it. Giant snip of places where you can find the data you asked about The answer I am loking for is not important for me. I have come accros an information that astronomers add the orbital speed of the Earth to the radial speed of stars measured with the spectrographic method. The radio method are the same like the spectrography. But it contradicts MMX. So I am trying to clear it. Uh.. no.. you have a theory or question, but aren't willing or able to do the work (or find someone else to do the work) to actual resolve the issue. Yes. I am not able. But here is nothing to do. Some people know the Doppler effects components: "the Doppler has several components: one from the rotation of Earth, one from the rotation of Mars (for a surface asset), and one from the relative motion of Mars and Earth" I am looking for information about relative motion of "Mars and Earth" and "Earth and Pioneer". Tons of data Tons of analysis out there You've got a question, you need to answer it. (or, just wait until someone else happens to answer it for you...) "wait until someone else happens to answer it for you..." is the only possibility. Sooner or later it will be in textbooks. Now in textbooks no Michelson-Gale experiment. S* |
Radio Astronomy
Szczepan Bialek wrote:
Uh.. no.. you have a theory or question, but aren't willing or able to do the work (or find someone else to do the work) to actual resolve the issue. Yes. I am not able. But here is nothing to do. Some people know the Doppler effects components: "the Doppler has several components: one from the rotation of Earth, one from the rotation of Mars (for a surface asset), and one from the relative motion of Mars and Earth" I am looking for information about relative motion of "Mars and Earth" and "Earth and Pioneer". You sound like the man in the street who claims that "the theory of relativity is wrong". But in your case you don't even refer to something as complex as relativity but as simple as doppler shift. There are existing formulas that allow you to calculate the doppler shift when knowing the speed of the items, and the measured results confirm what you calculate. So why do you keep questioning it? When you have found an old article that does not agree with what is measured today, why do you keep insisting that the old article is correct and suggeest the theory is wrong, when you don't have the capability to back that up with proofs that you present yourself? Isn't it better to assume that the measurements in the old article were not correct? |
Radio Astronomy
"Rob" napisal w wiadomosci ... Szczepan Bialek wrote: Uh.. no.. you have a theory or question, but aren't willing or able to do the work (or find someone else to do the work) to actual resolve the issue. Yes. I am not able. But here is nothing to do. Some people know the Doppler effects components: "the Doppler has several components: one from the rotation of Earth, one from the rotation of Mars (for a surface asset), and one from the relative motion of Mars and Earth" I am looking for information about relative motion of "Mars and Earth" and "Earth and Pioneer". You sound like the man in the street who claims that "the theory of relativity is wrong". But in your case you don't even refer to something as complex as relativity but as simple as doppler shift. There are existing formulas that allow you to calculate the doppler shift when knowing the speed of the items, and the measured results confirm what you calculate. So why do you keep questioning it? It is true for the Earth rotating. For the orbital movement of the Earth the result is null according to "the theory of relativity". When you have found an old article that does not agree with what is measured today, why do you keep insisting that the old article is correct and suggeest the theory is wrong, when you don't have the capability to back that up with proofs that you present yourself? Isn't it better to assume that the measurements in the old article were not correct? In physics textbooks the old article is correct. Once mo "Today's spectrograph astronomers assume that the effect is not null. It seems to me that today's astronomers are wrong because in physics are still null result. So I am looking for the result from communication with the spacecraft." I should wrote: "Some astronomers ASSUME..." To be precise now are available the spectrograph with built-in the corrections for the all movements of the Earth and Sun. But user can switch off same of them. It seems to me that at measurements of the radial speeds of stars the correction for the orbital speed of the Earth should be switched-off. What is your opinion? S* |
Radio Astronomy
Szczepan Bialek wrote:
What is your opinion? S* You don't want to hear that. It would hurt your ego. |
Radio Astronomy
"Rob" napisal w wiadomosci ... Szczepan Bialek wrote: What is your opinion? S* You don't want to hear that. It would hurt your ego. Not the case. In 1905 Einstein wrote: "Examples of a similar kind, as well as the unsuccessful attempts to substantiate the motion of the earth relative to the "light-medium", ..." It is still valid. One of the attempts was famous MM. In 1925 Michelson-Gale "substantiate the motion of the earth ROTATION relative to the "light-medium". It is in agreement with SR. (Like Sagnac). But things are changing. May be that the attempts with using the radio waves supply the opposite results. But I do not come across on such. So I am asking the radio experts. S* |
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