The earth's ozone layer occurs in the stratosphere, primarily between 10 and 30 miles altitude. Upper atmospheric effects of the hf active auroral research program ionospheric research instrument ( HAARP IRI)ĭOE Office of Scientific and Technical Information (OSTI.GOV) The HAARP HF transmitter (or heater), which JOURNAL OF GEOPHYSICAL RESEARCH, VOL. The HF-ELF conversion efficiency at HAARP is thus estimated to be.Program ( HAARP ) research station in Gakona, Alaska. The.conductivity variation (created by modulated HF heating) and radiating 4–32 W. HAARP ) HF transmitter in Gakona, Alaska, and detected after propagating more than 4400 km in the Earth-ionosphere waveguide to Midway Atoll. With higher heater frequency, the loss.1304 local time) and on 13 April from 0812 to 0844 UTC (0012 to 0044 local time), using the HAARP transmitter facility at Gakona, AK, at full powerĮLF Waves Generated by Modulated HF Heating of the Auroral Electrojet and Observed at a Ground Distance of Approximately 4400 km Ionospheric Modification from Under-Dense Heating by High-Power HF TransmitterĪuroral Research Program ( HAARP ) is a HF transmitter, which delivers 0.36 to 3.6 GW effective isotropic radiated powers (F.IRP) for the nse heating, the EIRP of the HAARP heater can be increased significantly by increasing the heater frequency. We compare the minimum and maximum cross-modulation effect and the amplitude of the resulting cross-modulation waveform to the expected power-law dependence of ELF/VLF wave amplitude on HF power. The peak power of the modulating beam was incremented in 1-dB steps. HAARP was operated in a dual-beam transmission format: the first beam heated the ionosphere using sinusoidal amplitude modulation while the second beam broadcast a series of low-power probe pulses. The experiments were performed during the March 2013 campaign at the High Frequency Active Auroral Research Program ( HAARP) Observatory. The results are compared to previously published dependencies of ELF/VLF wave amplitude on HF peak power. HF cross-modulation measurements are used to evaluate the efficiency of ionospheric conductivity modulation during power-stepped modulated HF heating experiments. In this paper, we apply experimental observations of HF cross-modulation to the related problem of ELF/VLF wave generation. High frequency ( HF) cross modulation experiments are a well established means for probing the HF-modified characteristics of the D-region ionosphere. Power-Stepped HF Cross Modulation Experiments at HAARP Tyrnov, HF radar observations of decaying artificial field aligned irregularities, J. This presentation will summarize the database and the estimated diffusion rates, and will discuss the potential for targeted experiments for aeronomy measurements. The database has been examined to extract decay time estimates and diffusion rates over a range of ionospheric conditions. Experiments often cycled the heater power on and off in a way that allowed estimates of the FAI decay rate. A large database of radar backscatter from HAARP generated FAI has been collected over the years. demonstrated using the decay of radar scatter above the Sura heating facility to estimate irregularity diffusion. The decay of the irregularities, however, has not been so widely studied yet it has the potential for providing estimates of the parameters of natural irregularity diffusion, which are difficult measure by other means. Creation of FAI in HF ionospheric modification experiments has been studied by a number of authors who have developed a rich theoretical background. Suitable experiments at the High-frequency Active Auroral Research Program ( HAARP) facilities in Gakona, Alaska, create a region of ionospheric Field-Aligned Irregularities (FAI) that produces strong radar backscatter observed by the SuperDARN radar on Kodiak Island, Alaska. Observations of HF backscatter decay rates from HAARP generated FAI For several cycles, small bright airglow spots were observed whenever HAARP was on. HAARP was modulated at intervals of several seconds. In the presence of aurora and a strong blanketing E layer. HAARP to optically measure fine structure in the ionosphere and to study airglow sources. CONTRACT NUMBER Telescopic Imaging of Heater-Induced Airglow at HAARP N0. Simultaneous observations of all six components of the ELF.signals generated by the HAARP heater are also simultaneously observed at a nearby ground-based site, allowing a comparison of the ELF power in the Kenned圓.Frequency Active Auroral Research Program ( HAARP ) facility in Gakona, Alaska, (located at L 4.9). DEMETER Observations of ELF Waves Injected With the HAARP HF TransmitterĭEMETER observations of ELF waves injected with the HAARP HF transmitter M.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |