NAVIGATION AID

Abstract: A navigation aid for use with printed maps, the aid comprising: (a) a receiver of transmitted signals from a geographic position fixing system such as, for example, GPS, which receiver is operative to determine from the transmitted signals the current geographic coordinates of the navigation aid; (b) an electronic database means storing a plurality of sets of data, each set of data comprising definitive parameters of a respective map or series of maps for definition of the correspondence between the coordinates of the map grid associated with the map and the coordinates of the geographic position fixing system; (c) a map identity input means for the user to enter into the aid the identity of the map to be used therewith and data selection means responsive to the input identity to select from the database the set of data corresponding to the map identified by the user; (d) processing means for converting the currently determined geographic coordinates into the corresponding map grid coordinates of the identified map using the selected data; and (e) a display for displaying the thus-established corresponding map grip coordinates to the user.

Description: NAVIGATION AID Technical field The present invention relates to a Navigation aid Background Since the 1930s various signal transmitting techniques have been developed for the purpose of enabling the precise location of ships, planes, vehicles and other objects to be determined Initially, these were land based systems such as GEE, OBOE, DECCA, LORAN, PULSE-8 and OMEGA which provided the means for the location of a ship or aircraft on the Earth's surface to be determined to various degrees of precision and position update rates The years since the early 1980's have witnessed the arrival of satellite-based position fixing systems Initially there was the TRANSIT system, subsequently the American GPS (Global Positioning System) and Russian GLONAS systems have been introduced Now, the most widely used system is GPS, with the LORAN-C and CHAYKA (the Russian equivalent of LORAN-C system) increasingly becoming accepted as the backup systems. In view of its capability for precise measurement of position, applications for GPS vary widely At one end of the scale the level of accuracy of sophisticated receivers combined with accuracy-enhancement techniques permits GPS to measure the movement of the Earth s surface and movement within large structures such as suspension bridges At the other end of the scale low cost, hand-held GPS units enable the location of users to be determined to an accuracy of approximately 100 metres Many types of GPS receiver are available but the type of GPS receiver used in the greatest numbers is probably the hand-held receiver which is used extensively for marine navigation Essentially, a position fixing device contains two elements the position-determining sensor which determines location, and the processing and time measurement element which analyses information provided by the position-determining sensor and provides position and time-derived information such as speed, direction of travel, bearing, time and distance to destination, estimated time of arrival and off-track error One of the areas where GPS and LORAN-C are most highly valued is marine navigation where the means to accurately determine a vessel's location has contributed significantly to safe navigation. For land applications, navigation systems tend to be less widely used, not least because of the difficulties associated with presenting position-related information A mariner presented with a position in geographic co-ordinates normally has the means (in the form of parallel rulers, dividers, a latitude and longitude annotated chart and a chart table) and skill to convert the geographic co-ordinates to a point on a chart Assuming he has the skill, a land user such as a motorist when presented with the same geographic co-ordinates is unlikely to have the means to identify the location on a road map or city street plan, resulting in a situation where the user is presented with position in Latitude and Longitude to an accuracy of better than 100 metres, but - without the means to identify location relative to the user's environment through the use of a map - the information has little value There are other potential users of GPS such as tourists who are unlikely to find a small hand-held GPS useful and for the same reason as a motorist. The use of digital map displays does, to a limited extent, overcome the problem of displaying information but there are several drawbacks including cost, power requirements, the availability of digital map data and, most importantly, the size of the aid. If a user of a digital map is navigating between two points several miles apart in a large city he can identify both points on the aid by zooming out, resulting in the map being displayed at a smaller scale. However, the process of zooming out will involve either displaying a map with a reduced amount of detail - and in practise this could mean that the road network the navigator wishes to study in order to plan a route may disappear - or, if the detaii of the map does not drop out a the user zooms out, the map will become cluttered with detail to the extent that it becomes unreadable. The requirements of a navigator to observe the relationship between points such as the start and end of a journey, and the need to identify detail between the points, are the primary reasons for maps being traditionally much larger in size than the conventionally sized pages of a book, and very much larger than a convenient, useable electronic aid. The invention that is the subject of this application overcomes digital map-related problems by avoiding the use of digital map aids altogether, and presenting information to a user in such a way that without any equipment and with minimal skill a user may rapidly and easily identify a location on a conventional paper map. In addition, all information that is expected of a conventional navigation receiver such as geographic co-ordinates, speed, bearing and distance to waypoint, off-track error and estimated time of arrival may be displayed Maps are generally marked with a regular grid enabling points on their surface to be located with the assistance of an indexing system. Grid lines run vertically and horizontally to form a matrix of squares or rectangles which may be referred to as cells Every cell has a unique map grid co-ordinate expressed by the letter or number across the top of the map identifying the cell's position to the left or right , and another letter or number identifying the cell's position between the top and bottom of the map In a book of maps every cell has a unique identifier expressed commonly as letter, number plus a page number The present invention provides an important link between the information provided by a GPS receiver and the use of a grid-marked map Summary of the Invention According to a first aspect of the present invention there is provided a navigation aid for use with printed maps, the aid comprising (a) a receiver of transmitted signals from a geographic position fixing system such as, for example, GPS,, which receiver is operative to determine from the transmitted signals the current geographic co-ordinates of the Navigation aid, (b) an electronic database means storing a plurality of sets of data, each set of data comprising definitive parameters of a respective map or series of maps for definition of the correspondence between the coordinates of the map grid associated with the map and the coordinates of the geographic position fixing system, (c) a map identity input means for the user to enter into the aid the identity of the map to be used therewith and data selection means responsive to the input identity to select from the database the set of data corresponding to the map identified by the user; (d) processing means for converting the currently determined geographic coordinates into the corresponding map grid co-ordinates of the identified map using the selected data; and (e) a display for displaying the thus-established corresponding map grid coordinates to the user. According to a second aspect of the present invention there is provided a navigation aid for use with printed maps, the aid comprising: (a) A transparent overlay for a map, the overlay being marked with a grid having cells of a predetermined cell size, the grid having grid co-ordinate-identifying letters, numbers or the like along the X and Y axes of the grid for identifying each cell; (b) a receiver of transmitted signals from a geographic position fixing system such as, for example, GPS;, which receiver is operative to determine from the transmitted signals the current geographic co-ordinates of the navigation aid (c) an electronic database means storing data comprising definitive parameters of one or more maps or series of maps for definition of the correspondence between the coordinates of the map grid associated with the or each map and the coordinates of the geographic position fixing system; (d) processing means for converting the currently determined geographic coordinates into the corresponding map grid co-ordinates of the identified map using the stored data; and (e) a display for displaying the thus-established corresponding map grid coordinates to the user, wherein in (c), (d) and (e) the mapgrid co-ordinates of the map grid associated with the or each map are the co-ordinates of the grid on the transparent overlay when it is operably positioned on the map. Preferably in the Navigation aid immediately above the overlay has securing means to secure the overlay in a specific position with respect to the map to ensure maintenance of the chosen registration between the map and the grid Suitably the overlay is the front face of a waterproof wallet for the map. Alternatively, where the map is a marine navigation chart, the overlay is suitably a sheet dimensioned to suit the navigation chart. According to a further aspect of the present invention there is provided a Navigation aid for use with printed maps, the aid comprising' (a) a receiver of transmitted signals from a geographic position fixing system such as, for example, GPS;, which receiver is operative to determine from the transmitted signals the current geographic co-ordinates of the navigation aid (b) an electronic database means storing data comprising definitive parameters of one or more maps or series of maps for definition of the correspondence between the coordinates of the map grid associated with the or each map and the coordinates of the geographic position fixing system, (c) processing means for converting the currently determined geographic coordinates into the corresponding map grid co-ordinates of the identified map using the stored data, (d) a display for displaying the thus-established corresponding map grid co- ordinates to the user, and (e) the aid being adapted to display, at the users option, by operating a switch provided on the aid the geographic co-ordinates determined by the receiver or the corresponding map grid co-ordinates Description of the Preferred Embodiments The aid suitably has an LCD or similar display screen which displays not only the coordinates of the cell of a map within which the geographic co-ordinates of the navigation aid currently lie but also displays an image of the cell with a marker of the point within the cell that corresponds to the user's geographic co-ordinates Three segments of information - a graphic display of the cell, the identity of the cell and the point within the cell that corresponds to the user's location - are suitably displayed by the display giving the user the ability to refer to the map and identify on the map the cell that is displayed by the Navigation Aid and identify the point within that cell that corresponds to the user's precise location The cell displayed by the Navigation Aid will preferably be the same size as the cell on the map but if the size of the cell on the map is too large to be displayed at 1 1 scale on the Navigation aid then the cell will be displayed at reduced size but with the same height to width ratio. The size and height to width ratio of the cell displayed on the Navigation aid may be configured by the user so that the Navigation Aid system can be used in conjunction with any map that is geographically accurate. The Navigation aid cannot be used with a map which is a diagrammatic or schematic map. As an option, the Navigation aid may show the numerical value expressed in a user- defined measurement unit with the absolute distance of the position point on the map in terms of units from the upper or lower and left or right edge of the map cell being displayed. When the Navigation aid is to be used in conjunction with a book of maps it may be that the book of maps contains more than one map encompassing the same area. For example, a map of a country may include the capital of the country in a very small-scale map covering the whole country, another map may include the capital at a large scale, and another yet larger scale map may include various sectors of the capital. In this case the Navigation aid will suitably advise the user by means of additional information on the display that the location of the user falls within three different map cells, and the identity of each cell will be displayed to the user who will be given the option of selecting any cell. Furthermore, if the geographic location of the user is covered by more than one map, the identity of the other maps may also be displayed. When initially programming the database of the Navigation aid the relationship between the map cell structure and geographic co-ordinates must be established for each map. The geographic extent of the area covered by each map cell must be entered into the Navigation aid's database indirectly or by a general formula from which the extent of each map may be determined. A simple approach to achieve this would be to define the geographic co-ordinates of the corners of each cell on the map but this would require the Navigation Aid to store an unduly large amount of data. A better approach is to identify the characteristics of the matrix of cells covering the map, identify the geographic co-ordinates of the corners of the map, and provide the Navigation aid with a conversion program enabling the geographic area covered by each cell to be determined. If the map to be used is a book of maps the area covered by each map must be determined or detemninable from the data entered into the aid's database. Parameters are preferably stored as formulae in order to reduce the amount of data held within the aid's database. Once the relationship between geographic co-ordinates and the cell matrix of a map has been established and stored in the database a unique reference number is assigned to that data to enable it to be retrieved for use When a user wishes to use the Navigation aid the user may input the reference number of the map. Alternatively, a sensor such as a bar code reader may be built into the Navigation aid enabling it to detect the identity of the map that is being used with the Navigation aid. (Note: when a user begins to use the Navigation aid, a menu of maps will appear and the user simply selects whichever map is appropriate to his requirements. The conversion parameters necessary for converting wide area co-ordinates to map coordinates for a London A-Z can in principle be stored as 304 characters or bytes, provided that the data is held within a tightly defined structure, or format. Typically, conversion data for a map can be held within 340 bytes meaning that 3 publications can be stored by 1020 bytes of information or 1 kilobyte (1 kilobyte has 1,024 bytes) Thus it is realistic for a database with a 3 megabyte storage capacity to store 9,000 sets of conversion parameters By way of example of use, if the user is in Pans, he might choose to select a logged Pans street atlas The act of selecting the appropriate map via the map identity input facility will result in the stored conversion parameters for that map, being invoked, so that the wide area co-ordinates (lat-long) can be presented as map co-ordinates which are appropriate to the atlas (eg 49 degrees 32'48" N.001 degree 22'34" might be appropriately presented as Page 6, co-ordinates C5, plus a graphic display which will show a graphic image of square C5 and the location of the user in the appropriate point of C5) If the user is using the Navigation aid on a moving boat or vehicle, the location of the user can be displayed together with a line which indicates the past track of the user, and as the user moves across the Earth's surface so the Navigation aid will show the position-indicating point moving across the appropriate cell When the user s position changes to the extent that it moves out of the area covered by the cell or off the display, the Navigation aid will cause the appropriate adjacent cell to be displayed with the user's position on that cell The Navigation aid's display may be configured so that the user's position is always shown at the centre of the display, and as the user s position moves so the cell and adjoining cells will move so that the user s position remains at the centre of the aid If the user is moving North the displayed cell matrix will move down the aid, if the user is moving East the displayed cell matrix will move to the left of the aid Always, all of the cell that accommodates the user's position will be displayed and preferably all or parts of adjacent cells will be displayed The display is suitably provided with the ability to zoom in or out so that as desired the cell can be seen as one of the whole range of cells on a complete page The X representing the location of the user on the displayed cell image will still be shown in the correct position (subject to the resolution of the display screen), but the user will see his location moving across a page or part page of a map rather than simply moving across a specific cell of the map, giving the user a more intuitive feel for his progress In instances where no grid exists on a map a user may be provided with the ability to superimpose a grid on the map in the form of a stable non-stretch template Provided that the grid is defined by a regular pattern, preferably with parallel lines vertically and horizontally across the surface of the map at regular spacings, any arbitrary grid will suffice With the relationship between the cells of the map and geographic co-ordinates already established within the database of the display, the display is suitably adapted to enable points from a map to be entered The Navigation aid software will suitably permit a user, having identified a point on a map, to input the point into the Navigation aid by entering the identity of the page that accommodates the cell and the identity of the cell that accommodates the point, and entering the position-indicating point within the cell For example, having studied a map a user may see that his destination lies within cell G4 on Page 48 of map reference number 1234, and that the position on the map of the point to be entered into the Navigation aid is 3mm from the right hand margin of the cell and 8mm from the top of the cell The Navigation aid operating software will permit the user to enter the information, e g that the destination lies within Cell G4 on Page 48 of map reference 1234, and that the relevant point lies 3mm from the right hand edge of the celi and 8mm from the bottom of the cell In instances where precision is not required the user will also be able to enter the approximate position point within a cell In this respect the user can enter geographic co-ordinates into the Navigation aid without being aware of latitude and longitude or any geographic co-ordinate system A Navigation aid user can thus define a journey from start to destination as a series of waypoints and the user can enter the position of each waypoint into the Navigation aid To facilitate accurate entry of, point co-ordinates for the marker within the displayed grid cell the display may be provided with a tracker ball or mouse integral or linked thereto Before the start of the journey - during the journey planning stage - the Navigation aid wili enable the user to select the directions which should be presented to the user as each waypoint is approached Directions may be graphic or expressed as letters and numbers During the journey the Navigation aid sensing that it is approaching a waypoint, will present the previously entered directions to the user Visibly displayed directions may be accompanied by an audible sound indicating to the user that a waypoint will shortly be reached Directions can be displayed to the user in advance of the user reaching the point where directions are required, taking into account the user s speed In heavy traffic with the user's average speed being below 20 kph information may be displayed 200m before the point where directions are required On a motorway where the user may be travelling at 100 kph, directions may be displayed 1 km in advance An additional feature of the Navigation aid may include a heading sensor so that the bearing of the destination relative to the user may be displayed graphically Alternatively, an external heading sensor linked by a data cable to the Navigation aid may be used The Navigation aid may be provided with the ability to receive information from other external databases For example, if the aid were adapted to access a database of campsites in Scotland, the user, while driving along a road, could ask the Personal Navigator what is the distance to the nearest campsιte(s) from my present location 9 The Personal Navigator could list campsites, starting with the nearest This information could, for example be entered by Smart Card, or by being interfaced to a computer In its primary mode the Navigation aid shows the user his location in terms of page number (if for an atlas), grid square and the location of the user within the map, on the grid square This is fine for a tourist using either product with a London A-Z, or a motorist using the product with a motoring atlas, but may not be as useful for a traditional user (a mariner navigating offshore) who wants to see his location presented in lat/long Accordingly a facility enabling a user to "toggle" or switch between "map interactive' operating mode (as referred to immediately above) and "conventional" operating mode displaying the conventional output of the GPS, or similar receiver where location is given in lat/long format A further additional feature of the Navigation aid may include a destination-by-postcode facility enabling a user to define his destination by entering the postcode The storage media for holding the database may be held within the Navigation aid or in an external device which may be linked by a data cable to the Navigation aid. Furthermore, the Navigation aid may include a bar code reader or other sensor as the map identity input means to enter the identity of the map with which the Navigation aid is being used. The display may also be provided with a facility for receiving broadcast accuracy- enhancement signals, enabling the Navigation aid to present more accurate position information. When hill walking many walkers have their maps held in a transport waterproof wallet In a further aspect of the present invention there is provided an display for use with a modified wallet where the front of the wallet (the clear plastic part of the wallet that protects the part of the map that the walker wishes to study) has a grid in it (eg, 1-20 across the top and A to T down the side)) Often, in practice the map is folded in the wallet so that it is impossible for the user to see any edge of the map, or in other words, he cannot see any part of the map co-ordinate system However, if the user were able to establish a relationship between the map co-ordinate system and the co-ordinate system on the front of the wallet, it would be possible for the aid to convert the geographic co-ordinate system (lat/long) or the map co-ordinate system to the co- ordinate system of the wallet. For this to happen, the user would suitably select three wallet intersection points (preferably spaced as far apart as possible) and enter the latitude and longitude or the underlying map co-ordinates for each of the three points For each such point the user would, for example enter the latitude and longitude co-ordinate (or map co-ordinate) of the point on the map that was directly below the point on the wallet. Once three points have been entered the Personal Navigator can present location in terms of the wallet co-ordinate system which would be very easy to read. The wallet should be adapted to ensure that the map within the wallet is firmly fixed and dos not move relative to the wallet. A further additional feature may include the facility for a user to update the internal database to identify the relationship between a map and the geographic co-ordinates of the map, when this information has not been provided by the map publisher or any other provider of information. The process will involve a Navigation aid user going to a point within the area covered by the map and manually identify the location of the point in terms of the cell structure (the identity of the cell and the location of the point within the cell) and identify the geographic co-ordinates of the same point This process may be repeated one or more times to enable the Navigation aid to establish the relationship between the geographic co-ordinates and the map's cell or pattern structure. As a variant of the adaptation for use by hill walkers the display may be further provided with a facility whereby a user at sea may cover his chart with a clear overlay preferably of plastic which is marked with an arbitrary grid. For example, across the top it would have ABC... and down the side it would have 123... The squares of the grid would suitably be, for example, about 1 cm square. The navigator could reference the grid to the chart by entering the lat/long co-ordinates of, for example, three plastic grid co-ordinates into the aid database. The advantage of this is that, provided the plastic overlay was firmly fixed to the chart, it would be very easy for the user to identify his position on the chart in terms of plastic overlay grid parameters and it would be possible for the navigator to mark his position with a chinagraph pencil (the pencil mark could be wiped clean after use) so that he had a record of positions. With the grid squares being only 1 cm square it would be very easy for the navigator to identify his location on the chart without the use of parallel rulers also, the chart could be folded in such a way that the edges of the chart (the part of the chart showing lat long co-ordinates) need not be visible. A further additional feature may enable the Navigation aid to alternate the graphic display of cells with position and time derived information

Claims: CLAIMS 1. A navigation aid for use with printed maps, the aid comprising: (a) a receiver of transmitted signals from a geographic position fixing system such as, for example, GPS;, which receiver is operative to determine from the transmitted signals the current geographic co-ordinates of the navigation aid; (b) an electronic database means storing a plurality of sets of data, each set of data comprising definitive parameters of a respective map or series of maps for definition of the correspondence between the coordinates of the map grid associated with the map and the coordinates of the geographic position fixing system; (c) a map identity input means for the user to enter into the aid the identity of the map to be used therewith and data selection means responsive to the input identity to select from the database the set of data corresponding to the map identified by the user; (d) processing means for converting the currently determined geographic coordinates into the corresponding map grid co-ordinates of the identified map using the selected data; and (e) a display for displaying the thus-established corresponding map grid coordinates to the user. 2. A Navigation aid as claimed in claim 1 wherein there is further provided a transparent overlay for a map, the overlay being marked with a grid having cells of a predetermined cell size, the grid having grid co-ordinate-identifying letters, numbers or the like along the X and Y axes of the grid for identifying each cell; wherein in (c), (d) and (e) of claim 1 the mapgπd co-ordinates of the map grid associated with the or each map are the co-ordinates of the grid on the transparent overlay when it is operably positioned on the map 3 A navigation aid as claimed in claim 1 or claim 2, the aid being adapted to display, at the users option by operating a switch provided on the aid, the geographic co-ordinates determined by the receiver or the corresponding map grid co-ordinates 4 A Navigation aid as claimed in any preceding claim wherein the display is adapted to display not only the map grid co-ordinates but also to provide a graphic image of the relevant cell with a marker therein indicating the corresponding position within the cell and wherein the display is adapted to show part or all of one or more adjacent cells and is preferably further adapted to zoom in or out and/or, if the aid is used while moving, scroll from display of one cell to display of another 5 A navigation aid for use with printed maps, the aid comprising (a) A transparent overlay for a map the overlay being marked with a grid having cells of a predetermined cell size, the grid having grid co-ordinate-identifying letters, numbers of the like along the X and Y axes of the grid for identifying each cell, (b) a receiver of transmitted signals from a geographic position fixing system such as, for example, GPS,, which receiver is operative to determine from the transmitted signals the current geographic co-ordinates of the navigation aid (c) an electronic database means storing data comprising definitive parameters of one or more maps or series of maps for definition of the correspondence between the coordinates of the map grid associated with the or each map and the coordinates of the geographic position fixing system; (d) processing means for converting the currently determined geographic coordinates into the corresponding map grid co-ordinates of the identified map using the stored data; and (e) a display for displaying the thus-established corresponding map grid coordinates to the user, wherein in (c), (d) and (e) the mapgrid co-ordinates of the map grid associated with the or each map are the co-ordinates of the grid on the transparent overlay when it is operably positioned on the map. 6. A Navigation aid as claimed in claim 5 werem the overlay has securing means to secure the overlay in a specific position with respect to the map to ensure maintenance of the chosen registration between the map and the grid 7. A Navigation aid as claimed in claim 5 or 6 wherein the overlay is the front face of a waterproof wallet for the map. 8. A Navigation aid as claimed in claim 5 or 6 wherein the overlay is a sheet and the map is a marine navigation chart, the sheet being dimensioned to suit the navigation chart. 9. A navigation aid for use with printed maps, the aid comprising: (a) a receiver of transmitted signals from a geographic position fixing system such as, for example, GPS;, which receiver is operative to determine from the transmitted signals the current geographic co-ordinates of the navigation aid (b) an electronic database means storing data comprising definitive parameters of one or more maps or seπes of maps for definition of the correspondence between the coordinates of the map grid associated with the or each map and the coordinates of the geographic position fixing system; (c) processing means for converting the currently determined geographic coordinates into the corresponding map grid co-ordinates of the identified map using the stored data; (d) a display for displaying the thus-established corresponding map grid coordinates to the user; and (e) the aid being adapted to display, at the users option, by operating a switch provided on the aid the geographic co-ordinates determined by the receiver or the corresponding map grid co-ordinates

Inventors: TURNER JOHN RICHARD MILES, TURNER, JOHN, RICHARD, MILES
Applicants: TURNER JOHN RICHARD MILES, TURNER, JOHN, RICHARD, MILES
Application year: 1997
Main classification: G01C21
IPC codes: G01C21, G09B29