Texas Instruments Corporation

Jerry L Setliff

Eugene A Robinson

Michael D Smith

John P Volpi

Richard D Hoffman

Gerald Burnham

An electronic chart system in which charts of the earth are stored in digital representation and communicated to the operator by a visual display. Through the use of a Loran-C receiver or the like, the system additionally plots the carrier's position on the visual representation of the chart. The visual display is a cathode ray tube on which the visual representation is compressed or expanded to meet the demands of the operator so that the appropriate resolution is thereby obtained. To minimize memory size an encoding format is used which provides a data word for indicating the first physical element of the run line, a data word for the number of runs per line and data words for the lengths of N-1 runs of up to two variables for each line of the chart.

Electronic chart system

A navigational aid and autopilot in which informational data pertaining to the physical operating conditions of the craft, the external characteristics relevant to the operation of the craft, and a chart mapping a selected portion of the surface of the earth in which the craft is operating are combined into a single communication correlating such data in a manner assisting an operator of the craft in the performance of his duties. The navigational aid measures external physical conditions such as radio transmissions, radar soundings, sonar soundings, and the like, as well as the physical state of the craft such as fuel flow, list of the craft, and speed of the motor. By monitoring these characteristics in association with an electronic chart, the system correlates and combines the total informational content in a comprehensive form so as to relieve the operator pilot of the necessity of integrating and correlating data from a plurality of different sources. The autopilot operation accepts two types of data command, the first being a destination, the second being a bearing and time duration. Through the use of a position determining means, such as a Loran-C receiver, the system controls the craft and its movement to the destination. With the help of the external physical condition monitors, the system provides course direction so that the craft will not collide with another boat nor run aground. The autopilot additionally plots the course for the craft.

Navigational aid autopilot

A Loran C receiver is disclosed which has a scanned type keyboard including data entry, primary function and special function keys. The primary function keys include an automatic key for selecting automatic operation. A microprocessor is controlled by the keyboard, a timing means, a real time interrupt, a counter, a groundwave phase and envelope sample strobe generator, a delayed phase channel sample strobe generator and a latches and multiplexer. The timing means orients the microprocessor as to time and triggers the counter. The counter provides the proper count to the groundwave phase and envelope strobe generator and delayed phase channel sample strobe generator for producing a plurality of sampling signals for the latches and multiplexer. The real time interrupt produces a data ready or cycle done signal for the microprocessor. The latches of the latches and multiplexer sample at selected time intervals digitized phase indicating outputs representative of the RF signals received by the receiver from master and secondary stations of a GRI. The multiplexer multiplexes the digitized phase information into the microprocessor in response to a command from the microprocessor. The command is given after receipt of the data ready (cycle done) signal. The microprocessor then processes the digitized phase information for GRI searching, coarse envelope and cycle identification of the master and secondary stations of the GRI and determining sequentially for display at regular intervals the time differences between the master station and each slave station.

Growing community of inventors

Dallas, TX, United States of America

Jerry L Setliff