Timing & Key Generation
Key Pulse Generator
The Hydrographic Survey Products KDD 2 is a Key Pulse generator that can be used in conjunction with Seismic and Hydrographic surveying equipment.
The KDD 2 can generate a stable key pulse stream with output key rates from 1mS to 9.999 seconds in 1mS increments. It can further generate a second key pulse delayed from the first by any time between 1mS to 65 seconds again in 1mS increments.
The KDD 2 can be used in Master or Slave Modes.
In Master Mode the KDD 2 uses a high accuracy 100KHz clock signal derived from its internal GPS receiver. This high accuracy clock is used to generate the key pulses as required by the operator. The second key pulse is delayed from the first and is also available as an output.
In Slave Mode an external key pulse is received by the KDD 2 and can be divided and/or delayed as required by the operator.
The KDD 2 may be configured from its front panel or via a USB interface. Parameters are displayed on a 4-line X 20 LCD display. All settings are retained when power is cycled for rapid starts.
Applications:
Enables several types of marine echo sounders, sonar and sub-bottom survey equipment to be operated at differing triggering rates without interference between them. Two or more KDD 2’s may be used together to eliminate any cross talk between systems.
Water column removal for deep water sub-bottom profiler systems. By triggering the recording system, a fixed time after the source has been triggered, the water column may be removed from the record.
Generation of non-standard trigger rates and delays.
Source synchronization.
Testing and evaluation of seismic source generators and transmitters
The HSP Key Pulse Conditioner / Buffer
The HSP Key Pulse Conditioner / Buffer provides a simple method to pre-condition Key Pulses used to trigger seismic sources. Software generated key pulses, often have slow rise times causing inaccurate trigger timing. Input Keys may be shortened or stretched to provide constant output pulse width with fast rise time.