4D velocity of Strombolian eruptions and man-made explosions derived from multiple Doppler radar instruments

An overview of volcano infrasound: From hawaiian to plinian, local to global

“…Although this method is useful and attractive for estimating mass flux, it is not valid for multipole (anisotropic) sources. Gerst et al (2008) integrated radar, video, and infrasound data to study the directivity of eruptions at Erebus Volcano, Antarctica and found that significant directivity exists for the majority of the explosions, indicating a dominant non-monopole component. This method for estimating mass flux may thus be accurate only for the most simple and idealized volcano-acoustic sources and recording environments.…”

Comparing near-regional and local measurements of infrasound from Mount Erebus, Antarctica: Implications for monitoring

“…Additional monitoring at Erebus operated by MEVO includes video recording, infrared sensors, GPS and tiltmeters , supplemented by additional monitoring during temporary field campaigns, including COSPEC and DOAS (Sweeney et al, 2008), FTIR and thermal camera (Oppenheimer et al, 2009) and doppler radar (Gerst et al, 2008).…”

Volcanological Applications of Doppler Radars: A Review and Examples from a Transportable Pulse Radar in L-Band

“…A comparison of some characteristics of weather radars and transportable volcano Doppler radars is presented in Table 1 Hort et al (2003) found an increase in eruption duration, much higher velocities and indirect evidence of mean particle size decrease after a rain storm. Gerst et al (2008) reconstructed the 4D velocity (directivity) of Strombolian eruptions at Erebus and Stromboli from 3 FM-CW radars. FM-CW radars have a narrower field of view (around 1° or so at 3 dB) and can thus target a precise sector of the volcanic emission but, on the other hand, lack the integrated information of longer wavelength pulse radars with a wider beam aperture and deeper range gates.…”

“…The absolute inclination angle cannot be retrieved directly firstly because velocities and power distribution vary strongly between explosions and also only the inclination angular component in the beam's vertical plane can be retrieved. Gerst et al (2008) solved this problem by using simultaneously 3 FM-CW radars to calculate the directivity of Strombolian eruptions and reconstruct time series of the 3-D directivity vector every second. Another solution is to best match the power spectral distribution in the different range gates (e.g., Fig.…”