Device for cartographically representing minimum vertical speeds
This device furnishes a map for assisting navigation at low-level altitude while representing the zone flown over with points shown in false colors and/or textures or symbols corresponding to the vertical speeds needed to fly over them.
1. A device for cartographically representing minimum vertical speeds for aircraft generating a navigation map from information in an elevation database of the terrain belonging to a particular maneuver region, comprising:
Curvilinear distance map generation means for generating, in the maneuver region, multiple curvilinear distance maps listing the lengths of the shortest paths leading from the current position of the aircraft to the various points of the maneuver region while observing vertical flight profiles associated with different vertical speeds for the aircraft,
means for combining, on one and the same final map, all the curvilinear distance maps obtained, selecting, for each point of the final map, the point geographically corresponding to it in the different curvilinear distance maps assigned the lowest curvilinear distance estimation, and
means of displaying the selected points, showing, for each selected point, the vertical speed associated with the vertical flight profile observed by its original curvilinear distance map.
2. The device as claimed in claim 1 , wherein the curvilinear distance map generation means apply, for the generation of each curvilinear distance map, a propagation distance transform constrained to observe a determined vertical flight profile associated with a determined vertical speed value for the aircraft.
3. The device as claimed in claim 2 , wherein the constrained propagation distance transform is a chamfer mask propagation distance transform.
4. The device as claimed in claim 1 , wherein the curvilinear distance map generation means generates a curvilinear distance map observing a vertical flight profile in two parts: a first flight part from the current position of the aircraft with a fixed duration and a determined vertical speed value followed by a second horizontal flight part.
5. The device as claimed in claim 4 , wherein the curvilinear distance map generation means generates a curvilinear distance map observing a vertical flight profile, the first part of which corresponds to a determined absolute vertical speed value independent of the current vertical speed of the aircraft.
6. The device as claimed in claim 4 , wherein the curvilinear distance map generation means generates a curvilinear distance map observing a vertical flight profile, the first part of which corresponds to a determined vertical speed value linked to the current vertical speed of the aircraft.
7. The device as claimed in claim 1 , wherein the curvilinear distance map generation means generate curvilinear distance maps observing vertical flight profiles associated with vertical flight speeds separated by an increment of 500 ft/min.
8. The device as claimed in claim 1 , wherein the curvilinear distance map generation means generate curvilinear distance maps observing vertical flight profiles associated with vertical flight speeds separated by an increment of 500 ft/min with an upper limit linked to the climb performance characteristics of the aircraft.