Assisted navigation systems and methods

1 . A method comprising:

receiving data by a logic device from a plurality of sensors associated with a mobile structure;

determining, by the logic device, a plurality of navigational hazards disposed within a monitored area associated with the mobile structure;

processing, by the logic device, the data and/or the navigational hazards to determine, for each point of a plurality of points in the monitored area:

a distance from the point to each of one or more navigational constraints for the mobile structure; and

the smallest distance of the distances from the point to the one or more constraints, the smallest distance being encoded into an operational context of the mobile structure;

generating, by the logic device, a context-dependent navigational chart for the mobile structure, wherein the navigational chart comprises greater or fewer of the navigational hazards in response to the determined smallest distances;

updating the navigational chart by the logic device in response to changes in the data; and

steering the mobile structure by a navigation control system in accordance with the updated navigational chart.

2 . The method of claim 1 , wherein:

the plurality of points comprises the plurality of the navigational hazards; and

the data comprises a speed, a heading, and/or a position of the mobile structure, wherein the mobile structure is a type of watercraft.

3 . The method of claim 1 , further comprising selectively generating an alarm associated with at least one of the navigational hazards in response to the operational context.

4 . The method of claim 1 , wherein the navigational hazards comprise tide heights associated with locations in the monitored area, wherein the processing comprises assigning weights to the tide heights and a distance between the mobile structure and the locations, wherein the generating comprises selectively providing the tide heights on the navigational chart in response to the weights.

5 . The method of claim 2 , wherein the navigational hazards comprise objects in the monitored area, wherein the processing comprises determining intercept times from the mobile structure to the objects and determining distances from each of the objects to one or more of the other objects, wherein the generating comprises selectively providing the objects on the navigational chart in response to the intercept times.

6 . The method of claim 1 , wherein the data comprises sounding data, wherein the processing comprises generating a Searoom map using the sounding data and adjusting the operational context using the Searoom map.

7 . The method of claim 5 , wherein the processing comprises assigning intercept time thresholds to types of navigational hazards, wherein the generating comprises selectively providing the navigational hazards on the navigational chart in response to their associated intercept time thresholds.

8 . The method of claim 1 , wherein the processing comprises determining clearance margins associated with the navigational hazards, wherein the generating comprises adjusting representations of the navigational hazards on the navigational chart in response to the clearance margins.

9 . The method of claim 7 , wherein the data comprises data associated with a target received from the plurality of sensors, wherein the processing comprises fusing the data to provide a single representation of the target used to determine the operational context;

wherein the method further comprises defining a plurality of urgency levels, and defining the intercept time thresholds separately for each of the plurality of urgency levels;

wherein the generating comprises selectively providing the navigational hazards on the navigational chart in response to their associated intercept time thresholds for a selected one of the urgency levels.

10 . The method of claim 1 , wherein the generating comprises representing the navigational hazards by a color-coded representation of at least a portion of the monitored area on the navigational chart.

11 . A system comprising:

a user interface device providing a display, wherein the user interface device is associated with a mobile structure; and

a logic device configured to communicate with the user interface device and a plurality of sensors associated with the mobile structure, wherein the logic device is configured to:

receive data from the sensors,

determine a plurality of navigational hazards disposed within a monitored area associated with the mobile structure,

process the data and/or the navigational hazards to determine, for each point of a plurality of points in the monitored area:

a distance from the point to each of one or more navigational constraints for the mobile structure; and

the smallest distance of the distances from the point to the one or more constraints, the smallest distance being encoded into an operational context of the mobile structure,

generate a context-dependent navigational chart for the mobile structure, wherein the navigational chart comprises greater or fewer of the navigational hazards in response to the determined smallest distances,

update the navigational chart in response to changes in the data, and

cause a navigation control system to steer the mobile structure in accordance with the updated navigational chart.

12 . The system of claim 11 , wherein:

the plurality of points comprises the plurality of the navigational hazards; and

the data comprises a speed, a heading, and/or a position of the mobile structure, wherein the mobile structure is a type of watercraft.

13 . The system of claim 11 , wherein the logic device is configured to selectively generate an alarm associated with at least one of the navigational hazards in response to the operational context.

14 . The system of claim 11 , wherein the navigational hazards comprise tide heights associated with locations in the monitored area, wherein the logic device is configured to assign weights to the tide heights and a distance between the mobile structure and the locations, wherein the logic device is configured to selectively provide the tide heights on the navigational chart in response to the weights.

15 . The system of claim 12 , wherein the navigational hazards comprise objects in the monitored area, wherein the logic device is configured to determine intercept times from the mobile structure to the objects and determine distances from each of the objects to one or more of the other objects, wherein the logic device is configured to selectively provide the objects on the navigational chart in response to the intercept times.

16 . The system of claim 11 , wherein the data comprises sounding data, wherein the logic device is configured to generate a Searoom map using the sounding data and adjust the operational context using the Searoom map.

17 . The system of claim 15 , wherein the logic device is configured to assign intercept time thresholds to types of navigational hazards, wherein the logic device is configured to selectively provide the navigational hazards on the navigational chart in response to their associated intercept time thresholds.

18 . The system of claim 11 , wherein the logic device is configured to determine clearance margins associated with the navigational hazards, wherein the logic device is configured to adjust representations of the navigational hazards on the navigational chart in response to the clearance margins.

19 . The system of claim 17 , wherein the data comprises data associated with a target received from the plurality of sensors, wherein the logic device is configured to fuse the data to provide a single representation of the target used to determine the operational context;

wherein the logic device is configured to define a plurality of urgency levels, and define the intercept time thresholds separately for each of the plurality of urgency levels;

wherein the generating comprises selectively providing the navigational hazards on the navigational chart in response to their associated intercept time thresholds for a selected one of the urgency levels.

20 . The system of claim 11 , wherein the logic device is configured to represent the navigational hazards by a color-coded representation of at least a portion of the monitored area on the navigational chart.