FN Archimer Export Format
PT J
TI VLF waves at satellite altitude to investigate Earth electrical conductivity
BT 
AF LEYE, P. O.
   TARITS, Pascal
AS 1:1;2:1;
FF 1:;2:;
C1 European Inst Marine Studies, Plouzane, France.
C2 UBO, FRANCE
UM LGO
IF 1.273
TC 2
UR https://archimer.ifremer.fr/doc/00639/75141/75492.pdf
LA English
DT Article
DE ;VLF;satellite;Earth
AB At and near the Earth surface, electromagnetic (EM) fields radiated from VLF transmitters are commonly used in geological exploration to determine the shallow Earth conductivity structure. Onboard satellites such as DEMETER, the electric and magnetic sensors detect the VLF signal in altitude. While we know for surface measurement that the VLF EM field recorded at some distance from the transmitter is a function of the ground conductivity, we do not know how this relationship changes when the field is measured at satellite altitude. Here we study the electromagnetic field radiated by a vertical electric dipole located on the Earth surface in the VLF range and measured at satellite altitude in a free space. We investigate the EM field as function of distance from the source, the height above the Earth surface, and the electrical conductivity of the Earth. The mathematical solution in altitude has more severe numerical complications than the well-known solutions at or near the Earth surface. We test most of the solutions developed for the latter case and found that direct summation was best at several hundred kilometers above the Earth. The numerical modeling of the EM field in altitude shows that the field remains a function of Earth conductivity. The dependence weakens with altitude and distance from the transmitter. It remains more important for the electric radial component. 
PY 2015
PD MAR
SO Radio Science
SN 0048-6604
PU Amer Geophysical Union
VL 50
IS 3
UT 000353686900008
BP 264
EP 281
DI 10.1002/2014RS005532
ID 75141
ER

EF