Navigation aids
First Claim
1. A navigational aid comprising:
- a charting surface (10);
a cursor device (16) movable over the surface;
means (10, 64,
66) to provide a signal indicative of the current position of the cursor device on the surface; and
means (54-58) to convert the current cursor position signal from being in terms of a coordinate system (x, y) of the charting surface to a chart-based signal indicative of the current position of the cursor device in terms of a coordinate system (Θ
, φ
) of the chart;
wherein the improvement comprisesmeans (58) to store a chart-based signal indicative of a previous current position of the cursor device and a current chart-based signal indicative of the current position of the cursor device so as to perform a desired navigational computation, and means (30-40, 46-52,
60) for providing an indication to the user of the computational result of said processing, whereinthe processing means is operable to calculate from a stored chart position from the previous current position, andthe indicating means comprises means (50,
60) to display the distance and bearing.
2 Assignments
0 Petitions
Accused Products
Abstract
An electronic cursor (12) is movable over a digitising table (10) on which a chart (16) has been spread. The cursor can give an indication of which way it should be moved to reach a defined position on the chart. The cursor can also convert positions in terms of x, y coordinates of the table into positions in terms of latitude and longitude co-ordinates of the chart, and can display the chart positions. The cursor can also determine bearings and distances between its own position and a defined position. Several other facilities are also available. Thus, the cursor can be used to facilitate the plotting of positions and courses on the chart and in reading off positions and bearings from the chart.
23 Citations
27 Claims
-
1. A navigational aid comprising:
-
a charting surface (10); a cursor device (16) movable over the surface; means (10, 64,
66) to provide a signal indicative of the current position of the cursor device on the surface; andmeans (54-58) to convert the current cursor position signal from being in terms of a coordinate system (x, y) of the charting surface to a chart-based signal indicative of the current position of the cursor device in terms of a coordinate system (Θ
, φ
) of the chart;wherein the improvement comprises means (58) to store a chart-based signal indicative of a previous current position of the cursor device and a current chart-based signal indicative of the current position of the cursor device so as to perform a desired navigational computation, and means (30-40, 46-52,
60) for providing an indication to the user of the computational result of said processing, whereinthe processing means is operable to calculate from a stored chart position from the previous current position, and the indicating means comprises means (50,
60) to display the distance and bearing. - View Dependent Claims (7, 8, 23)
-
-
2. A navigational aid comprising:
-
a charting surface (10); a cursor device (16) movable over the surface; means (10,64,66) to provide a signal indicative of the current position of the cursor device on the surface; means (54-58) to convert the current cursor position signal from being in terms of a coordinate system (x,y) of the charting surface to a chart-based signal indicative of the current position of the cursor device in terms of a coordinate system (θ
,φ
) of the chart;means (58) to store the chart-based signal, means (54-58) for processing a stored chart-based signal indicative of a previous current position of the cursor device and a current chart-based signal indicative of the current position of the cursor device so as to perform a desired navigational computation; and means (30-40,46-52,60) for providing an indication to the user of the computational result of said processing. - View Dependent Claims (3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
-
-
24. A navigational aid comprising:
-
a charting surface (10) for use with a chart (16) having a coordinate system (θ
,φ
);a cursor device (12) movable over the surface; means (10,64,66) to provide a surface-based signal indicative of the current position of the cursor device on the surface in terms of a coordinate system (x,y) of the charting surface; means (54,56,58) to convert the surface-based signal to provide a chart-based signal indicative of the current position of the cursor device in terms of the chart coordinate system; and means (54, 56, 58, 44 REF) to reference the chart coordinate system with respect to the surface coordinate system in dependence upon the positions (xn,xn) of at least two points on the surface and the coordinates (θ
n,φ
n) of those positions in terms of the chart coordinate system, the converting means being responsive to the referencing means to provide the conversion. - View Dependent Claims (25, 26, 27)
-
Specification