Paul Rodriguez | Independent Researcher (original) (raw)
Papers by Paul Rodriguez
We review experiments in ionospheric modification and long distance propagation performed at the ... more We review experiments in ionospheric modification and long distance propagation performed at the HAARP facility. Most experiments were in bistatic configuration with the WAVES receiver on the NASA/WIND satellite. Initial experiments showed scintillation-like variations in low frequency propagation through the earth's ionosphere. A HAARP-HIPAS transmission experiment set up a spatial interference pattern measured at WIND. The Kodiak SuperDARN radar scanned the modified region above HAARP and observed the growth of ionospheric irregularities. Recently, lunar echoes at 8 MHz were detected by WIND. The experiments at HAARP will extend to nonlinear regimes as power levels increase. DISCUSSION Over a period of several years, as the HF Active Auroral Research Program (HAARP) facility near Gakona, Alaska, has increased total power from 300 kW to 960 kW, we have conducted experiments in ionospheric modification and long distance propagation. Most of these experiments have been done in collaboration with the WAVES high frequency
Proceedings of the 2003 IEEE Radar Conference (Cat. No. 03CH37474)
At high frequency, radio waves will interact with space plasmas and surfaces of local astronomica... more At high frequency, radio waves will interact with space plasmas and surfaces of local astronomical objects, producing an echo that can provide new diagnostic data. The availability of high power radars operating at high frequencies opens a window for the remote investigation of our surrounding space environment. We discuss and illustrate this technique with some specific examples.
Journal of Geophysical Research, 1970
See p a g e f o l l o w i n g .
Journal of Geophysical Research, 1979
on a numbar of occasions during the 3.8-yr, operating lifetime of RAE-2, we observed strong terre... more on a numbar of occasions during the 3.8-yr, operating lifetime of RAE-2, we observed strong terrestrial kilometric radiation when the spacecraft was over the far side of the moon and when the low altitude terrestrial magnetosphere was completely obscured from view. If these deep lunar occultation events are used to infer radio source locations, then we find that the apparent source must sometimes be situated at geocentric distances of 10 to 40 RE or more. From an analysis of these events, we show that they are probably due to propagation effects rather than the actual generation of the emission at such large distances. The kilometric radiation can be generated near the Earth at auroral latitudes and subsequently 'strongly scattered in the magnetosheath and nearby solar wind to produce the large apparent distances. The most likely scatterers are density inhomogenieties in the magnetosheath plasma and ion plasma waves in the magnetosheath and the upstream solar wind.
Geophysical Research Letters, 2000
High frequency (HF) radiation from the HAARP and SURA ionospheric heaters transmitted through the... more High frequency (HF) radiation from the HAARP and SURA ionospheric heaters transmitted through the underdense ionosphere and received by the WIND satellite show the presence of strong spatial structure in the radiation pattern. A simple model based on the combination of ionospheric irregularities and interference effects has been developed to account for the observations. The analysis demonstrates the utility of satellite receptions as probes of ionospheric irregularities created or enhanced by powerful HF radio waves.
Planetary and Space Science, 2004
Initial studies of the Sun's corona using a solar radar were done in the 1960s and provided measu... more Initial studies of the Sun's corona using a solar radar were done in the 1960s and provided measurements of the Sun's radar crosssection at about 38 MHz. These initial measurements were done at a time when the large-scale phenomenon known as a coronal mass ejection was unknown; however, these data suggest that coronal mass ejections (CMEs) may have been detected but were unrecognized. That solar radar facility, which was located at El Campo, TX, no longer exists. New solar radar investigations are motivated by our modern understanding of CMEs and their effects on the Earth. A radar echo from an Earthward-directed coronal mass ejection may be expected to have a frequency shift proportional to velocity; thus providing a good estimate of arrival time at Earth and the possible occurrence of geomagnetic storms. Solar radar measurements may also provide new information on electron densities in the corona. The frequencies of interest for solar radars fall in the range of about 10-100 MHz, corresponding to the lower range planned for the low-frequency array. In combination with existing or new high-power transmitters, it is possible to use the low-frequency array to re-initiate radar studies of the Sun's corona. In this report, we review the basic requirements of solar radars, as developed in past studies and as proposed for future investigations.
Journal of Geophysical Research, 1981
This issue contains results presented at the Upstream Wave and Particle Workshop held at the Jet ... more This issue contains results presented at the Upstream Wave and Particle Workshop held at the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California on April 15-16, 1980. This overview article summarizes the results of the collective ISEE work. ...
and on behalf of the LWA Consortium. The Long Wavelength Array (LWA), currently under constructio... more and on behalf of the LWA Consortium. The Long Wavelength Array (LWA), currently under construction in New Mexico, will be an imaging HF/VHF interferometer providing a new approach for studying the Sun-Earth environment from the surface of the sun to the Earth’s ionosphere. The LWA will be a powerful tool for solar physics and space weather investigations, through its ability to characterize a diverse range of low-frequency, solar-related emissions, thereby increasing our understanding of particle acceleration and shocks in the solar atmosphere along with their impact on the Sun-Earth environment. As a passive receiver the LWA will directly detect Coronal Mass Ejections (CMEs) in emission, and indirectly through the scattering of cosmic background sources as they propagate towards Earth. If coupled with a suitable transmitter, the LWA would be an excellent receiver for solar radar, potentially demonstrating accurate geomagnetic storm prediction from the Earth’s surface. Both radar an...
Review of Scientific Instruments, 1996
ABSTRACT
Geophysical Monograph Series, 1998
We present results from the NRL Floating Probe (FP) which made high time resolution measurements ... more We present results from the NRL Floating Probe (FP) which made high time resolution measurements of spacecraft charging and discharging on the Space Power Experiments Aboard Rockets (SPEAR III) payload. SPEAR III was specifically designed to study the physics of spacecraft charging phenomena. We know that spacecraft in the ionosphere can charge to high levels (up to a few kilovolts). Charging occurs naturally in the auroral region due to high-energy streaming electrons or during the operation of active experiments (ion/electron beams or electromagnetic tethers). Charging and discharging events are often impulsive in nature and a method fast enough to track these potential changes will be extremely important. The FP consists of a metallic sphere containing a high-impedance amplifier and a capacitive divider network for scaling large voltages to the range that solid state circuits can handle. The probe can be used for either positive or negative polarity measurements. The 'worst case' time-response is associated with negative charging since the probe must collect ions to stay in contact with the local plasma. Modeling of the FP indicates that it has a time response faster than 1 ms for the entire range of negative charging normally associated with spacecraft (0 to -2 kV). We will discuss the FP design, construction, and theory of operation. SPEAR III also carried an ElectroStatic particle Analyzer (ESA) for monitoring the incoming ion distribution and a comparison of these two measurements is presented.
Geophysical Monograph Series, 2013
Measurements of ionospheric electron temperatures with Langmuir probes are usually done with a te... more Measurements of ionospheric electron temperatures with Langmuir probes are usually done with a technique that sweeps a bias voltage to determine the current-voltage (IV) characteristic for the local plasma. We report on results in the use of a technique which is ...
Geophysical Surveys, 1981
This report sponsored by the Earth Physics Program of the Office of Naval Research, is an attempt... more This report sponsored by the Earth Physics Program of the Office of Naval Research, is an attempt to bring together in a coherent manner, for those involved in magnetic surveys, the relevant aspects of the external geomagnetic field. Although there are several excellent introductory texts ...
Review of Scientific Instruments, 1995
Abstract We present a method for measuring large changes in the electrical potential of a spacecr... more Abstract We present a method for measuring large changes in the electrical potential of a spacecraft. It is known that a spacecraft in the ionosphere can obtain voltages as large as a few kilovolts. Spacecraft charging can occur naturally in the auroral regions due to high‐ ...
Review of Scientific Instruments, 1994
In laboratory experiments related to space plasma physics it is often desirable to produce plasma... more In laboratory experiments related to space plasma physics it is often desirable to produce plasmas with characteristics as close as possible to various naturally occurring plasma regimes. In the near-earth region space plasma densities typically vary from 103-lo7 cmW3 and ...
Journal of Spacecraft and Rockets, 1992
Fig. 3 Spectrograms of the signals from the magnetic (top) and electric (bottom) antennas during ... more Fig. 3 Spectrograms of the signals from the magnetic (top) and electric (bottom) antennas during the barium chemical release from the CRRES spacecraft at 08:37:07 UT on July 19, 1991. magnetic antenna. The total signal in-band is also averaged and recorded each second. In a separate mode, the signal from the electric antenna is passed from the E-field electronics package to the B-field electronics package as well as to the E-field electronics package as shown in Fig. 1. The combined output then doubles the sampling rate of the signal from the electric antenna to 500 samples/s for a Nyquist frequency of 250 Hz.
Journal of Geophysical Research, 1976
Journal of Geophysical Research, 1985
Journal of Geophysical Research, 1995
The Ionospheric Focused Heating rocket was launched on May 30, 1992. The sounding rocket carried ... more The Ionospheric Focused Heating rocket was launched on May 30, 1992. The sounding rocket carried an instrument and chemical payload along a trajectory that crossed the intersection of the beams from the 430-MHz incoherent scatter radar and the 5.1-MHz high-power radio wave facility near Arecibo. The release of 30 kg of CF3Br into the F region at 285 km altitude produced an ionospheric hole that acted like a convergent lens to focus the HF transmissions. The power density inside the radio beam was raised by 12 dB immediately after the release. A wide range of new processes were recorded by in situ and ground-based instruments. Measurements by instruments flying through the modified ionosphere show small-scale microcavities (< 1 m) and downshifted electron plasma (Langmuir) waves inside the artificial cavity, electron density spikes at the edge of the cavity, and Langmuir waves coincident with ion gyroradius (4 m) cavities near the radio wave reflection altitude. The Arecibo incoherent scatter radar showed 20 dB or greater enhancements in ion acoustic and Langmuir wave turbulence after the 5.1-MHz radio beam was focused by the artificial lens. Enhancements in airglow from chemical reactions and, possibly, electron acceleration were recorded with optical instruments. The Ionospheric Focused Heating experiment verified some of the preflight predictions and demonstrated the value of active experiments that combine high-power radio waves with chemical releases. 1.
We review experiments in ionospheric modification and long distance propagation performed at the ... more We review experiments in ionospheric modification and long distance propagation performed at the HAARP facility. Most experiments were in bistatic configuration with the WAVES receiver on the NASA/WIND satellite. Initial experiments showed scintillation-like variations in low frequency propagation through the earth's ionosphere. A HAARP-HIPAS transmission experiment set up a spatial interference pattern measured at WIND. The Kodiak SuperDARN radar scanned the modified region above HAARP and observed the growth of ionospheric irregularities. Recently, lunar echoes at 8 MHz were detected by WIND. The experiments at HAARP will extend to nonlinear regimes as power levels increase. DISCUSSION Over a period of several years, as the HF Active Auroral Research Program (HAARP) facility near Gakona, Alaska, has increased total power from 300 kW to 960 kW, we have conducted experiments in ionospheric modification and long distance propagation. Most of these experiments have been done in collaboration with the WAVES high frequency
Proceedings of the 2003 IEEE Radar Conference (Cat. No. 03CH37474)
At high frequency, radio waves will interact with space plasmas and surfaces of local astronomica... more At high frequency, radio waves will interact with space plasmas and surfaces of local astronomical objects, producing an echo that can provide new diagnostic data. The availability of high power radars operating at high frequencies opens a window for the remote investigation of our surrounding space environment. We discuss and illustrate this technique with some specific examples.
Journal of Geophysical Research, 1970
See p a g e f o l l o w i n g .
Journal of Geophysical Research, 1979
on a numbar of occasions during the 3.8-yr, operating lifetime of RAE-2, we observed strong terre... more on a numbar of occasions during the 3.8-yr, operating lifetime of RAE-2, we observed strong terrestrial kilometric radiation when the spacecraft was over the far side of the moon and when the low altitude terrestrial magnetosphere was completely obscured from view. If these deep lunar occultation events are used to infer radio source locations, then we find that the apparent source must sometimes be situated at geocentric distances of 10 to 40 RE or more. From an analysis of these events, we show that they are probably due to propagation effects rather than the actual generation of the emission at such large distances. The kilometric radiation can be generated near the Earth at auroral latitudes and subsequently 'strongly scattered in the magnetosheath and nearby solar wind to produce the large apparent distances. The most likely scatterers are density inhomogenieties in the magnetosheath plasma and ion plasma waves in the magnetosheath and the upstream solar wind.
Geophysical Research Letters, 2000
High frequency (HF) radiation from the HAARP and SURA ionospheric heaters transmitted through the... more High frequency (HF) radiation from the HAARP and SURA ionospheric heaters transmitted through the underdense ionosphere and received by the WIND satellite show the presence of strong spatial structure in the radiation pattern. A simple model based on the combination of ionospheric irregularities and interference effects has been developed to account for the observations. The analysis demonstrates the utility of satellite receptions as probes of ionospheric irregularities created or enhanced by powerful HF radio waves.
Planetary and Space Science, 2004
Initial studies of the Sun's corona using a solar radar were done in the 1960s and provided measu... more Initial studies of the Sun's corona using a solar radar were done in the 1960s and provided measurements of the Sun's radar crosssection at about 38 MHz. These initial measurements were done at a time when the large-scale phenomenon known as a coronal mass ejection was unknown; however, these data suggest that coronal mass ejections (CMEs) may have been detected but were unrecognized. That solar radar facility, which was located at El Campo, TX, no longer exists. New solar radar investigations are motivated by our modern understanding of CMEs and their effects on the Earth. A radar echo from an Earthward-directed coronal mass ejection may be expected to have a frequency shift proportional to velocity; thus providing a good estimate of arrival time at Earth and the possible occurrence of geomagnetic storms. Solar radar measurements may also provide new information on electron densities in the corona. The frequencies of interest for solar radars fall in the range of about 10-100 MHz, corresponding to the lower range planned for the low-frequency array. In combination with existing or new high-power transmitters, it is possible to use the low-frequency array to re-initiate radar studies of the Sun's corona. In this report, we review the basic requirements of solar radars, as developed in past studies and as proposed for future investigations.
Journal of Geophysical Research, 1981
This issue contains results presented at the Upstream Wave and Particle Workshop held at the Jet ... more This issue contains results presented at the Upstream Wave and Particle Workshop held at the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California on April 15-16, 1980. This overview article summarizes the results of the collective ISEE work. ...
and on behalf of the LWA Consortium. The Long Wavelength Array (LWA), currently under constructio... more and on behalf of the LWA Consortium. The Long Wavelength Array (LWA), currently under construction in New Mexico, will be an imaging HF/VHF interferometer providing a new approach for studying the Sun-Earth environment from the surface of the sun to the Earth’s ionosphere. The LWA will be a powerful tool for solar physics and space weather investigations, through its ability to characterize a diverse range of low-frequency, solar-related emissions, thereby increasing our understanding of particle acceleration and shocks in the solar atmosphere along with their impact on the Sun-Earth environment. As a passive receiver the LWA will directly detect Coronal Mass Ejections (CMEs) in emission, and indirectly through the scattering of cosmic background sources as they propagate towards Earth. If coupled with a suitable transmitter, the LWA would be an excellent receiver for solar radar, potentially demonstrating accurate geomagnetic storm prediction from the Earth’s surface. Both radar an...
Review of Scientific Instruments, 1996
ABSTRACT
Geophysical Monograph Series, 1998
We present results from the NRL Floating Probe (FP) which made high time resolution measurements ... more We present results from the NRL Floating Probe (FP) which made high time resolution measurements of spacecraft charging and discharging on the Space Power Experiments Aboard Rockets (SPEAR III) payload. SPEAR III was specifically designed to study the physics of spacecraft charging phenomena. We know that spacecraft in the ionosphere can charge to high levels (up to a few kilovolts). Charging occurs naturally in the auroral region due to high-energy streaming electrons or during the operation of active experiments (ion/electron beams or electromagnetic tethers). Charging and discharging events are often impulsive in nature and a method fast enough to track these potential changes will be extremely important. The FP consists of a metallic sphere containing a high-impedance amplifier and a capacitive divider network for scaling large voltages to the range that solid state circuits can handle. The probe can be used for either positive or negative polarity measurements. The 'worst case' time-response is associated with negative charging since the probe must collect ions to stay in contact with the local plasma. Modeling of the FP indicates that it has a time response faster than 1 ms for the entire range of negative charging normally associated with spacecraft (0 to -2 kV). We will discuss the FP design, construction, and theory of operation. SPEAR III also carried an ElectroStatic particle Analyzer (ESA) for monitoring the incoming ion distribution and a comparison of these two measurements is presented.
Geophysical Monograph Series, 2013
Measurements of ionospheric electron temperatures with Langmuir probes are usually done with a te... more Measurements of ionospheric electron temperatures with Langmuir probes are usually done with a technique that sweeps a bias voltage to determine the current-voltage (IV) characteristic for the local plasma. We report on results in the use of a technique which is ...
Geophysical Surveys, 1981
This report sponsored by the Earth Physics Program of the Office of Naval Research, is an attempt... more This report sponsored by the Earth Physics Program of the Office of Naval Research, is an attempt to bring together in a coherent manner, for those involved in magnetic surveys, the relevant aspects of the external geomagnetic field. Although there are several excellent introductory texts ...
Review of Scientific Instruments, 1995
Abstract We present a method for measuring large changes in the electrical potential of a spacecr... more Abstract We present a method for measuring large changes in the electrical potential of a spacecraft. It is known that a spacecraft in the ionosphere can obtain voltages as large as a few kilovolts. Spacecraft charging can occur naturally in the auroral regions due to high‐ ...
Review of Scientific Instruments, 1994
In laboratory experiments related to space plasma physics it is often desirable to produce plasma... more In laboratory experiments related to space plasma physics it is often desirable to produce plasmas with characteristics as close as possible to various naturally occurring plasma regimes. In the near-earth region space plasma densities typically vary from 103-lo7 cmW3 and ...
Journal of Spacecraft and Rockets, 1992
Fig. 3 Spectrograms of the signals from the magnetic (top) and electric (bottom) antennas during ... more Fig. 3 Spectrograms of the signals from the magnetic (top) and electric (bottom) antennas during the barium chemical release from the CRRES spacecraft at 08:37:07 UT on July 19, 1991. magnetic antenna. The total signal in-band is also averaged and recorded each second. In a separate mode, the signal from the electric antenna is passed from the E-field electronics package to the B-field electronics package as well as to the E-field electronics package as shown in Fig. 1. The combined output then doubles the sampling rate of the signal from the electric antenna to 500 samples/s for a Nyquist frequency of 250 Hz.
Journal of Geophysical Research, 1976
Journal of Geophysical Research, 1985
Journal of Geophysical Research, 1995
The Ionospheric Focused Heating rocket was launched on May 30, 1992. The sounding rocket carried ... more The Ionospheric Focused Heating rocket was launched on May 30, 1992. The sounding rocket carried an instrument and chemical payload along a trajectory that crossed the intersection of the beams from the 430-MHz incoherent scatter radar and the 5.1-MHz high-power radio wave facility near Arecibo. The release of 30 kg of CF3Br into the F region at 285 km altitude produced an ionospheric hole that acted like a convergent lens to focus the HF transmissions. The power density inside the radio beam was raised by 12 dB immediately after the release. A wide range of new processes were recorded by in situ and ground-based instruments. Measurements by instruments flying through the modified ionosphere show small-scale microcavities (< 1 m) and downshifted electron plasma (Langmuir) waves inside the artificial cavity, electron density spikes at the edge of the cavity, and Langmuir waves coincident with ion gyroradius (4 m) cavities near the radio wave reflection altitude. The Arecibo incoherent scatter radar showed 20 dB or greater enhancements in ion acoustic and Langmuir wave turbulence after the 5.1-MHz radio beam was focused by the artificial lens. Enhancements in airglow from chemical reactions and, possibly, electron acceleration were recorded with optical instruments. The Ionospheric Focused Heating experiment verified some of the preflight predictions and demonstrated the value of active experiments that combine high-power radio waves with chemical releases. 1.