The Model 1100ES displays range and direction to the release. This feature offers quicker recovery times since lengthy triangulations are eliminated.

The Model 1100ES Command Unit is a portable, DC operated Acoustic Command Transmitter, Transponder Interrogator and Receiver. Combined with the Model 1120B Segmented, Ultra Short Baseline (USBL) Transducer and microprocessor control, the Model 1100ES provides bearing readouts of +/- 2 deg. nominal.

The 1100ES has an RS-232-C output that can be used directly for printing range and bearing information, or with optional InterOcean supplied PC-compatible software tabular data on several underwater units can be displayed or saved for future reference. The optional software may also provide visual displays of transponder and ships information. Plan, elevation and 3-D views of location information can be available.

A hardware option is available that adds a flux-gate compass to the 1120B Transducer. This, with the corresponding processing within the 1100ES , provides all bearing references relative to magnetic North from a free hanging transducer, independent of the ships reference. This eliminates the concern of fix mounting the transducer to the vessel. Digital readouts and visual display of bearing data is then North referenced.

The transmitter is designed to send a full set of unique coded underwater acoustic commands. It contains a programmable code generator, high powered acoustic transmitter, automatic gain receiver, digital signal processing and digital readout and display.

The transponder interrogator provides a codes signal to interrogate the acoustic transponder instrument used with the 1100ES. The standard interrogate frequency is 12 Khz with other frequencies programmable from the front panel keyboard. The interrogator also provides the start signal for the digital range indicator and bearing calculation system. This feature allow the user to determine the slant range and relative bearing form the command unit to the underwater transponder. The transpond pulse width is keyboard selectable by the user to provide optimum pulse width depending on acoustic conditions.

The receiver is used to detect and indicate receipt of the transponder reply signals and the confirmation of pinger signals. Its high gain receiver is equipped with automatic gain control, keyboard adjusted volume control, range and bearing display. The standard receive frequency is 8 KHz. Other reply frequencies are available and the acoustic receiver can be provided with multiple frequency selection.

The 1100ES Acoustic Command System uses a sequential tone coding technique which is a highly secure coding scheme making accidental or false triggering of the command receiver virtually impossible. The individual codes are made up of four out of a possible eight frequencies which are selected by front panel keypad input.

The Model 1120B Segmented USBL Command Transducer contains an omni-directional element for transmitting and receiving and four transducer elements for determining bearing. The standard transducer is supplied with 30 meters of cable. An optional 'tow fish' housing is available for use with the 1120B, which allows underway measurements to be made.