4648080 Method for determining the far field signature of a marine seismic source from near-field measurements

1987 ◽  
Vol 14 (5) ◽  
pp. iv
Keyword(s):  
Near Field ◽  
Field Measurements ◽  
Seismic Source ◽  
Far Field ◽  
Marine Seismic

Single water gun far‐field pressure signatures estimated from near‐field measurements

Geophysics ◽  
1985 ◽  
Vol 50 (2) ◽  
pp. 257-261 ◽  
Author(s):  
M. H. Safar
Keyword(s):  
High Resolution ◽  
Data Acquisition ◽  
Seismic Data ◽  
Near Field ◽  
Field Measurements ◽  
Reference Source ◽  
Far Field ◽  
Air Gun ◽  
Seismic Data Acquisition ◽  
Marine Seismic

An important recent development in marine seismic data acquisition is the introduction of the Gemini technique (Newman, 1983, Haskey et al., 1983). The technique involves the use of a single Sodera water gun as a reference source together with the conventional air gun or water gun array which is fired a second or two after firing the reference source. The near‐field pressure signature radiated by the reference source is monitored continuously. The main advantage of the Gemini technique is that a shallow high;resolution section is recorded simultaneously with that obtained from the main array.

Antenna Far Field Reconstruction by a Minimum Near Field Measurements

1984 ◽  
Author(s):  
G. D'Elia ◽  
G. Leone ◽  
R. Pierri ◽  
G. Schirinzi
Keyword(s):  
Near Field ◽  
Field Measurements ◽  
Far Field ◽  
Field Reconstruction

scholarly journals Scattering centers modeling of non-anechoic measurement environments

2012 ◽  
Vol 10 ◽  
pp. 69-73 ◽  
Author(s):  
K. A. Yinusa ◽  
C. H. Schmidt ◽  
T. F. Eibert
Keyword(s):  
Near Field ◽  
Field Measurements ◽  
Field Pattern ◽  
Far Field ◽  
Scattering Centers ◽  
Field Transformation ◽  
Field Radiation ◽  
Echo Suppression ◽  
Multipath Signals ◽  
Far Field Pattern

Abstract. Near-field measurements are established techniques to obtain the far-field radiation pattern of an Antenna Under Test via near-field measurements and subsequent near-field far-field transformation. For measurements acquired in echoic environments, additional post-processing is required to eliminate the effects of multipath signals in the resulting far-field pattern. One of such methods models the measurement environment as a multiple source scenario whereby the collected near-field data is attributed to the AUT and some scattering centers in the vicinity of the AUT. In this way, the contributions of the AUT at the probe can be separated from those of the disturbers during the near-field far-field transformation if the disturber locations are known. In this paper, we present ways of modeling the scattering centers on equivalent surfaces such that echo suppression is possible with only partial or no information about the geometry of the scatterers.

Far-field tsunami data assimilation for the 2015 Illapel earthquake

2019 ◽  
Vol 219 (1) ◽  
pp. 514-521 ◽  
Author(s):  
Y Wang ◽  
K Satake ◽  
R Cienfuegos ◽  
M Quiroz ◽  
P Navarrete
Keyword(s):  
Data Assimilation ◽  
Near Field ◽  
Source Parameters ◽  
Deep Ocean ◽  
Seismic Source ◽  
Far Field ◽  
Complementary Method ◽  
East Pacific ◽  
2015 Illapel Earthquake ◽  
Illapel Earthquake

SUMMARY The 2015 Illapel earthquake (Mw 8.3) occurred off central Chile on September 16, and generated a tsunami that propagated across the Pacific Ocean. The tsunami was recorded on tide gauges and Deep-ocean Assessment and Reporting of Tsunami (DART) tsunameters in east Pacific. Near-field and far-field tsunami forecasts were issued based on the estimation of seismic source parameters. In this study, we retroactively evaluate the potentiality of forecasting this tsunami in the far field based solely on tsunami data assimilation from DART tsunameters. Since there are limited number of DART buoys, virtual stations are assumed by interpolation to construct a more complete tsunami wavefront for data assimilation. The comparison between forecasted and observed tsunami waveforms suggests that our method accurately forecasts the tsunami amplitudes and arrival time in the east Pacific. This approach could be a complementary method of current tsunami warning systems based on seismic observations.

Sign in / Sign up

Export Citation Format

Share Document