Diehl Bgt Defence Gmbh Co., Kg

Diehl Munitionssysteme Gmbh & Co. Kg

Diehl Defence Gmbh & Co. Kg

Diehl Munitionssysteme Gmbh & Co.

Helmut Hofmann

Geoffrey Staines

Josef Dommer

Robert Stark

Jürgen Urban

Frank Sonnemann

In a method for generating a transillumination signal of a section of the subsurface, an HPEM radiation source radiates an electromagnetic pulse into the section for the purpose of exciting electromagnetically reactive structures to emit an electromagnetic response signal. For the pulse, a pulse duration of at most 500 ns, a center frequency in the range between 10 MHz and 10 GHz, and a bandwidth in the range from 10% to 150% of the center frequency is set. The transillumination signal is formed as the sum of response signals received at a measuring location. In a method for detecting a cavity in the subsurface, the above method is carried out, and the structures are detected from the transillumination signal with the aid of a detection method, and the cavity is detected if the structures satisfy a detection criterion.

Transillumination of the subsurface, method of cavity detection and detection configuration

The functionally critical series connection of high-voltage-resistant resistors (Rn, R'n) in a Marx generator () is replaced according to the invention by a molding (&#x2032;) composed of conductive plastic, which, depending on the configuration grouping of the capacitor bank (Cn), runs over the geometric series of capacitor connections (An, A&#x2032;n) resulting from this and is connected to them, for example by riveting or screwing (), in which case it is also possible to use more than one continuous molding, instead of a single molding.

Marx generator

The superimposition of the microwave fields of an array () of microwave generators (), with self-firing spark gaps () for the discharge of storage devices (), which are charged up to a high voltage, results in an increase in field strength and a capacity for influencing the frequency spectrum of the emitted high-energy high-frequency field and the emission direction thereof.

Microwave generator

Intensive microwave radiation in particular of great band width and energy over a relatively long period of time in the form of long pulse packets with a high pulse repetition frequency and a very high frequency spectrum can be achieved if microwave irradiation is effected during the discharge of a capacitive high-voltage generator () by way of the antenna () into a series of successive capacitors () to be connected in parallel. They are preferably constructed in the form of a concentric stack, connected to the antenna (), of which the outer electrodes () which are at a reference potential are in the form of a continuous tube within which annular electrodes () are disposed on a carrier () in axially spaced relationship with each other in such a way that at the same time they act as the electrodes of arc switches () for successively switching on subsequent capacitors (). The switch response characteristics and the charging time constants of the capacitor () which is respectively switched on therewith and the number thereof determine the length of the packet of high-frequency individual pulses () and thus the radiated microwave energy which can be still further increased by an increase in the capacitance of the capacitors ().

Growing community of inventors

Gräfenberg, Germany

Helmut Hofmann