CA1194999A - Data base for aircraft navigation system - Google Patents
Data base for aircraft navigation systemInfo
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- CA1194999A CA1194999A CA000411254A CA411254A CA1194999A CA 1194999 A CA1194999 A CA 1194999A CA 000411254 A CA000411254 A CA 000411254A CA 411254 A CA411254 A CA 411254A CA 1194999 A CA1194999 A CA 1194999A
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Abstract
DATA BASE FOR AIRCRAFT NAVIGATION SYSTEM
Abstract To enhance the usefulness of computerized airborne navigation systems, such as VLF/Omega systems, a data base using magnetic bubble memories is provided to store data relating to navigation points and aids.
Accessibility of the navigation data is improved by storing the records containing data for each naviga-tion point or aid in the alpha-numerical sequence of the navigation point or aid identifier in the magnetic bubble memory. Updating of the data base is facilitated by a removable memory module containing the magnetic bubble memories that is readily removable from an interface unit installed in the aircraft and adapted to be plugged into an update unit located at a central point outside of the aircraft.
Abstract To enhance the usefulness of computerized airborne navigation systems, such as VLF/Omega systems, a data base using magnetic bubble memories is provided to store data relating to navigation points and aids.
Accessibility of the navigation data is improved by storing the records containing data for each naviga-tion point or aid in the alpha-numerical sequence of the navigation point or aid identifier in the magnetic bubble memory. Updating of the data base is facilitated by a removable memory module containing the magnetic bubble memories that is readily removable from an interface unit installed in the aircraft and adapted to be plugged into an update unit located at a central point outside of the aircraft.
Description
DATA BA5E FOR AIRCRAFT NAVIG~TION SYSTEM
T~chnical Field The invention relates to the field of onboard aircraft navigation systems and, in particular, to data bases associated with such navigation systems contalning data relating to navigation aids and points.
Background of the Invention In order to obtain relevant information about navigation aids such as position and frequencies along with information about airport runways and outer markers, the pilot has typically had to consult a large number of charts or other paper publications. Because these charts and publications are usually bulky and hard to handle, problems are quite often created in the limited space of a cockpit. In addition it can taXe valuable time to find the appropriate navigational aid and its associated data on a chart or in a printed publication.
There have been a number of attempts to integrate data bases holding a large amount of information about navigation aids in aircraft navigation sys~emsO However, the amount of data that can be storecl has been limited due to the relatively small amount of data storage available in semiconductor memories. Alternatively mass storage devices such as disc memories have been proposed for st~ring the navigation information. One such sy~tem is disclosed in Hendrickson U.S. Patent 4t220,~4. ~owever~
mechanically based memories as shown in Hendrickson are no~
always the most appropriate for use in aircraft, especially corporate type aircraft d~e to space limitations and the requirement for reliabili~y.
In addition to being readily available, it i5 extremely important that the data base used in an aircrat navigations system be easily updated since information published by official government sources relating to navigation aids is typically updated at periodic intervals, usually every 28 days.
Summary of the Invention It is therefore an object of the invention to provide a data base for aircraft navigation systems that includes an electronic memory having at lea~t 2000 data records where each of the data records contains data relating to navigation points including the individual navigation point identifier and location coordinates, the capability for accessing one of the records having data relating to a particular navigation point utilizing the identifier for that point; a way of periodically updating the navigation point data in the electronic memory; and an interface for connecting the electronic memory to an airborne navigation computer.
It is an additional object of the invention to provide a data base for aircraft navigation systems that includes at least one magnetic bubble memory having a memory area divided into a predetermined number of data pages and where a group of the data pages are divided into data records that includes navigation data and the identifier for a navigation point and a controller circuit for operatively controlling the magn~tic bubble memory.
It is a further object of the invention ~o provide a removable memory module for use with a data interface unit of an aircraft navigation syst~m having a housing adapted to be received within the data int~rface unit;
at least one circuit board including a hulk electronic memory secuxed within the housing; an electrical connector connected to the printed circuit board and adapted to connect with the connector in the interfac-unit; and a latch for releasably securing the housing to the in~erface unit.
Brief Description of the Drawings Fig. 1 is a block diagram of an aircraft airborne navigation system utilizing a data base containing navigational point information;
Fig. 2 is a block diagram of an aircraft airborne navigation data base circuit;
Fig. 3 is a block diagram of a data update unit circuit;
Fig. 4 is a graphical representation of data page formats for use within an aircraft navigation data base;
Fig. 5 is a graphical representation of record formats for use with the data record pages of Fig. 4;
Fig. 6 is a perspective view of a data interface unit incluaing a removable memory module;
Fig. 7 is an interior view of the memory module taken along lines 7-7 of Fig. 6; and Fig. 8 is a view of a circuit board including a magnetic bubble memory for use in the memory module of Figs. 6 and 7.
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Detailed Description of the Invention -In Fig. 1 illustrated in block diagram fcrm is an aircraft navigation system util:izing a data base containing information relating to various navigational aids and navigational points. As shown in Fig. 1, a magnetic tape is received from a source such as the Jeppsen Company or other sources such as the ~nited States or other governments containing navigation information for various navigation aids or navigation points such as VOR-DME, nondirectional ~eacons, waypoints and airport information including the position of the airport along with the positions of the airport's outer markers and runways. Typically, the data on the magnetic tape 10 is formatted in accordance with ARINC Specifica-tion 424 as published by Aeronautical Radio, Inc., ofAnnapolis, Maryland.
As indicated by the dashed line 12, the magnetic tape 10 is received and used as an input to ~ data converter 14, which can be any conventional type of data processing equipment such as a Digital Equipment Corporation PDP-ll, and converts the data contained on the tape 10 into a format acceptable for input into an airborne navigation data base. This data format is discussed in detail in connection with Figs. 4 and 5.
The reformatted data is then output by the data converter 14 to a magnetic tape cartridge 16 as indicated by the dashed line 18 which in turn is utilized as an input, as indicated by the dashed line 20 to an update unit 22.
The tape cartridge 16 is inserted into a slot 24 in the data update unit 22.
Also inserted into another receptical 26 is a memory module 32 as indicated by the dashed line 30 Navigation data from the tape cartridge 16 is then .
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transferred by the update unit 22 to the memory module 32 which is plugged into the slot 26 of the up~ate unit as indicated by dashed line 30.
When the navigation data has been completely transferred to the memory module 32, the memory module 32 is removed from the receptical 26 in the update unit 22 and inserted in~o an interface unit 28 in the aircraft.
Equipment that is installed in the aircraft is indicated in Fig. l by means of the dashed line 34. In the aircraft, the update unit is electrically connected by means of a cable 36 to an airborne navigation system 38. In the preferred embodiment of the invention, the airborne navigation system is a GNS 500A Series 3 VLF/Omega aircraft navigation system sold by Global Navigation, Inc. As shown in Fig~ l, the control display unit (CDU) is connected directly to the interface unit 28 by the cable 36. Included in the navigation system CDU 38 is a cathode ray tube display 40 for displaying various types of navigation information of the type stored in the memory module 32 and an alpha-numeric keyboard 42 for entering data, requesting types of data, and control-ing the navigation system.
In Fig. 2 of the drawings is a block diagram of the electronic circuits contained within the interface unit 28 which are generally indicated as being within the dashed lines 44 and a block diagram of the electronic circuits contained in the memory module 32 as indicated by the dashed lines 46.
Included in the interface unit circuitry 44 is a microprocessor 48 connected by means of a line 50 to a read only memory 52 that contains a program for control-ling the operation of the microprocessor 48. Also connected to the microprocessor 48 by means of line 54 is a random access memory 56 for the temporary storage of data that is either being input or out:put through the interface unit 44. A power supply 58 is al50 included in the interface unit circuit 44 and is connec~ed ~y means of a line 60 to a power source in the aircraft. Vata is received from the navigation system 38 over lines 36 by means of a buffer circuit 52 that is in turn connected to the microprocessor 48 by lines 64 and 660 When the memory module 32 is inserted in the interface unit 28, the microprocessor 48 is connected to the circuit board 48 of the memory unit 46 by means of a connector ~8.
In the preferred embodiment of the invention, the memory module 36 contains two magnetic bubble memories 70 and 72. The preferred magnetic bubble memory is an Intel 7110 one megabit bubble memory sold by Intel Corpora~ion of Santa Clara, California. Each of the magnetic bubble memories 70 and 72 are organized into 2048 pages with 512 bits per pageO Operation of the magnetic bubble memories 70 and 72 and associated circuits is described in detail in the Intel Corporation publication entitled BUBBLE MEMORY DESIGN ~ANDBOOK. Connected to each of the magnetic bubble memory units 70 and 72, by means of data lines 74 and 76, is a bubble memory controller circuit 78.
As with the magnetic bubble memory units 70 and 72, the preferred controller circuit is an Intel 7220 which is also described in detail in the above referenced Intel publication. The memory module circuit 47 a].so includes a five volt voLtage regulator 80 connected to the controller 78 by means of line 82. An oscillator 84 is connected to the magnetic bubble memory 70 and 72 by means of a line 88.
When the memory module 32 containing the circuit 44 i5 secured within the interface unit 28, the controller 78 is connected to the microprocessor 48 by means of connector 68.
Incl~ded in the connector 68 between the controller 78 and the microprocessor 48 are at least eight data lines indicated at 90 along with an interrupt line 92 a~d a data transfer request line 94, a read line 96 and a write line 98. Utilizing the control lines 92, 94, 96 and 98, the microprocessor 48 can control the navigation data flow from and to the controller 78 over data lines 90.
Power is supplied to the controller 78 from the voltage regulator 80 by means of line ~9. Power line 99 also goes to the oscillator 84 and bubble memories 70 and 72. One of the significant features of the invention is ~hat power is only applied to the bubble m~mories 70 and 72 when a request for data has been init:iated thereby substantially reducing the heat produced by the memories 70 and 72. When a request for data is received by the microprocessor 48, a signal is transmitted over line 97 to the power supply 58 which in turn applies power to the controller 78 over line 99 thru voltage regulat~r 80O In order to accommodate successive req~ests for data the microprocessor will cause the power supply 58 to maintain power to the memory module circuit 46 for a predetermined amount of time such as four seconds.
In Fig. 3 is provided a block diagr~m of the circuit used in the update unit 22. Included in the update unit circuitry is a microprocessor 100 which in the preferred embodiment of the invention is of the ame type as the microprocessor 48 in the interface unit circuit 44. The memory module 32 when inserted in the update unit 22 ls connected electrically by means of a connector 102. The lines connecting the memory module 32 to the micro-processor 100 are substantially the same as the lines connecting the microprocessor 48 to the controller 78 as shown in Fig. 1 including the parallel data lines 90. In addition, the update unit includes a power supply 104 that is connected to the microprocessor 100 by a line 106 and to the memory module 3~ by means of a line 108 through the connector 102. The update unit 22 also inc~-u~es a tape transport 110 whlch receives the magnetic tape cassette 16 when it is inserted into the slot 26 of the update unit 22 as shown in Fig. 1. A controller circuit 112 controls the tape transport 110 and the navigation data is transmitted over line 114 through the controller to the microprocessor 100 over ~ine 116.. The power supply 104 provides power to both the tape transport 110 and the controller 112 over a line 118. In operation when the tape cassette 16 is inserted into the update unit 22, the tape transport will read the magnetic tape cassette and transfer the navigation data to the microprocessor 100 which in turn will transmit the navigation data over data lines 90 to the memory module where it is loaded into the magnetic bubble memories 70 and 72.
The update unit in addition includes an interface board 120 that serves to control a display unit 122 by means of a line 124 and a set of input switches 126 by means of a line 128. The input switches 12~ can be used by an operator to set an address of a particular page in the memory module 32 and the interface board will cause the microprocessor by means of line 130 to access that particular page having that address and return a predetermined portion of the contents of that page through the interface board to the display 122. As a result, predetermined portions of contents of various pages with the memory module 32 can be checked~ In one type of operation each tape cassette 16 with new navigation data base information to be loaded into the memory module 32 is accompanied by a sticker with several addresses and the contents of a portion of the pages with those addresses printed thereon in order to provide an operator with an opportunity to test that the correct da~a is being loaded into the memory module 3~.
3~
g Since one of the ~.ost important objects of the invention is to provide for efficient storage and retrieval of the maximum amount of navigational data possible, the organization of the da~a within the magnetic ~ubble memories 70 and 72 is important. rn order to illustrate the preferred manner in which the data is stored within the magnetic bubble memories 70 and 72, Figs.
4 and 5 are provided to illustrate the manner in which the pages are organized along with the organization of the records within the pages. In a memory module 32 having two magnetic bubble memory units 70 and 72, there are 4096 pages of data available where each page contains 64 bytes or 512 bits of information. The pages are numbered zero to ~095 and are identiEied by a 12-bit address and are ordered sequentially. The data stored in the memory module 32 is compressed into binary form and the records are organized into a:Lpha-numeric order with all the record types and geographical areas inter-mixed. The alpha-numerical ordering is based on the identifier for each navigation aid or navigation point.
In order to minimize the space required for each record, each type of record has a slightly modified format so that varying types of information such as~latitude and longitude, frequency and station declination can be stored efficiently. As described more completely in connection with FigO 5, the records are yrouped into 64-byte pages with labels and check sums added.
As illustrated in Fig. 4, the first type of page 132 is located at page number zero and contains basic information with respect to the organization of ~he data in magnetic bubble memories 70 and 72. The first byte 134 consists of a label identifying t:he type of page along with miscellaneous flags. Information with respect to the effective date of the navigational data stored within the memory is contained within the second record area 136 and the effective date of any change inform~ivn is contained within the third record area 1380 In the four~h record area 140, the start addresses of sub-records are 5 stored and in the fifth record 14~, the start addresses of req.~elev. records are stored. Start addresses o the country name list are stored in ~he sixth record area l44 and the start address of the Airway ID list are stored in the seventh record area 146. The stop address of the Airway ID list is stored in record area 148. The rest of the record areas and the page 132 are not used in the preferred embodiment except for the two last bytes 150 which are ~sed to store a check sum.
The structure of the basic record page 152 is illustrated in Fig. 4. As with each of the other pages, the first byte 154 is used to store label information and the second byte 156 is not used at present. The remainder of the page 152 is divided into six 10-byte records 160 through 168 along with two bytes of check s~ data 170 and 1720 The third basic type of page ut:ilized in the magnetic bubble memory 70 and 72 is the sub-record page 174 which includes a label byte 176~ twenty sub-records R1 through R20 each of which is three bytes in length and two bytes of check sum 178 and 180.
In Fig. 5 are illustrated the various record formats that appear in the basic record page 152 of Fig.
4. There are four basic record formats: the VHF navi-gation aid 182 such as VOR-D~E; a nondirectional beacon 184; a waypoint 186; and an airport 188. Each record format is used to store data for a particular type of navigation point or aid. In each one of these records, ~3~
17 bits in a first field 190 is used to store the latitude of the navigation point and an 18-bit field 192 is ~sed to store the longitude of the navigation pointO Each of the basic records 182, 184, 186 and 188 also includes a label field 194, 196, 198 and 20Q to identify the type of record since each type of record has a somewhat different forma~
and the rec~rds are intermixed. Additionall~, the label fields 194, 19~, 198 and 200 indicate if there are any adjacent ambiguous identifiers. An ambiguous identiEier results when more than one navigation point has the same identifier. For example, there are a number of VOR stations located in different countries that have the same identifier. Each of the record types also has a field for storing the identifier for that particular navigation point. For the VHF navigations aid 182, a field 202 21 bits long is used to store an identifier of up to four alpha-numeric characters and the nondirectional beacon record 184 utilized a 27-bit field 204 to store an identifier of up to five alpha-numer:ic characters.
Similarly the waypoint record 186 utilizes a 27~bit field 206 to store a five letter identifier and the airport record 188 utilizes a 21-bit field to store an identifier of up to four alpha-numeric characters. In cc~nvertiny the alpha-numeric identifier into binary representation for storage in the identification fields 202, 204, 206 and 208, each identifier character is converted into a number from zero to 37 which in turn is stored in a binary representation in the appropriate label field 194, 196, 198 or 200.
Each of the basic records 182, 184, 186 and 188 also includes one bit 210 that indicates whether or not the change list for that particular navigation point is 3~
in effect. The VHF navigation aid record 182 also includes a bit that indicates whether or not ~he DME is located greater than a predetermined dista~ce from the VOR antenna. In some instances, the DME ante~na can be located as far as one-half mile from the ~GR ~ntenna and therefore will have a significantly different position as defined in latitude and longitude. ~ field 214 is also included in the record 182 t:o provide an indication of the magnetic variation of the navigation aid.
The nondirectional beacon record 184 includes a nine-bit field which provides the radio frequency of the beacon.
The airport record 188 inc:Ludes a field 218 that is used to store the starting address of the sub-records as sho~n in the sub-record page of Fig. 4. ~s shown in Fig. 5, a sub-record 220 includes an identification field 222 and a delta latitude field 224 and a delta longitude field 226. The starting address for the airport sub-record 220 will define both the page and the number of the record in that page so the beginning sub-record for that airport can be located directly. The identification field 222 of the sub-record indicates the nature of the point belng specified such as an outer marker or the number of a runway. The delta latitude and delta longitude fields 224 and 226, respectively, are combined with the value of latitude and longitude stored in the airport record 188 to get the exact position in latitude and longitude of the specific position contained in the sub-record 210.
The last signific~nt type of record utili~ed in the memory module 32 is a continuation record 228 that is used to store the same kind of information as in the other four major records 182, 184, 186 and 188 when there is an ambiguous identifier such that t~o or more naviga-tion points have the same identifier. Stored in an identifier field 230 is an international identiEier specified by ICAO that unambiguously identifies the navigation point. In addition to the identifier field 230, the continuation record includes a label Jield 232 to identify the type of record and a record field 234 that matches the appropriate record fields in one of the basic four records 1~2, lg4, 1~6 and 188.
With reference to the sub-record 220 in Fig~ 5, it should be noted that in order to provide complete information with respect to the identifier stored in the first field 222 which is only one-byte or eight-bits long, it is necessary to compress the data representing the ID. To utilize, for example, the first bit to indicate whether the record is representing an outer marker or a runT~ay and the second bit to indicate whether the outer marker is right or left with the other six bits remaining to indicate the outer marker or runway number does not provide for all the possible types o~ outer markers or runways. For example, in addition to right and left outer markers and runways~
there are in some cases center runways with center outer markers and in the cases where there is only a single runway there will be only a single outer marker. There-fore, there are six different combinations of outer markers and runways that need to be stored in the record 220.
In the preferred embodiment of the invention this is compensated for by assigning a number from one to six to the type of runway or outer marker and multiplying that designator by 35 and adding ~he runway number. This combination can then be stored in the ID field 222 in the existing eight bits. To decode the label, the identifier field 222 is divided by 36 to get an integer that represents the type of navigation point and the remainder will be the runway or outer marker number.
In a typical operation of a navigation system in conjunction with the navigation data base a pilot will select a navigation point for display nn the CRT 40 of the control and display unit of the navigation system 38 by entering the identifier by means of the alpha~numeric keyboard 42. Thls identifier is then transmitted by means of lines 36 through the buffer S2 of the interface module under control of the microprocessor to the controller 78 of the memory module 46 as shown in Fig. 2. Since the records 156 through 168 and the record pages 152 are stored in alpha-numerical order, one method of quickly accessing the relevant record is to perform a binary search on the record pages. The first step of the search is to fetch, under control of the microprocessor 48, the record page 152 that is approximately one-half way through the number of record pages. As indicated previously, the beginning and ending addresses of the record pages 152 are stored in the ~ero pase 132 so that the number of the pa~e halfway through the record page group is easily determined. The identifier of the navigation point to be selected is then tested against one of the identifiers of the selected record and if there is a match the pertinent information is transmitted back to the navigation system 38~ In a typical navigation system, such as the one described in connection with the preferred embodiment of the invention, there will be a number of storage locations where up to 127 navigation points can be stored in the navigation system 38 itself for immediate use by the navigation system. For example, many navigation systems set up flight plans with a series of waypoints and it is convenient to store the p*rtinent facts such as the position and frequencies of various waypoints and navigation aids directly in the navigation syste~ itself.
In the event a match is not found in the first comparison and the identifier being so~ght is higher than the one tested against, the microprocessor 48 will cause the controller 78 to fetch a record page that is approximately three-quarters of the way through the whole groJp of record pages. If the desired identifier i6 greater than the identifier of the record selected, then the microprocessor 48 will cause the controller to select a record page 152 which is approximately one-quarter of the way from the first record page. A comparison is then made and, if the desired record page is not found at this poin~, the same process is repeated until the desired record page is found. Since the binary search is usually successful in locating the appropriate page within eleven fetches, the record containing the desired navigation data can be located quickly enough to appear almost instantaneous to the operator. In this manner, a desired navigation point having a predetermined identifier can be rapidly selected from among the over 4000 record pages in the magnetic bubble memory 70 and 720 It should be also noted that the continuation records 228 that have the same identifiers as other records are located adjacent to the records with the same identifier. When a match is found with the desired identifierl the microprocessor 48 will cause the controller to produce adjacent records for examination~ In the preferred embodiment of the invention, one technique to identify the pertinent navigation points when more than one identifier is found is to compaee the present position of the aircraft as transmitted by the naviga-tion system 38 to the microprocessor 48 with each of the positions of the navigation aids found. Under the assumption that navigation aids with th~ sa~e iderltifier are usually located on different continents~ it is assumed that the person or system requesting the navigation poin~ is interested in the closest one.
As indicated before, navigation data is typically updated periodically, usually every 28 days, by the various authorities that publish the navigation data.
In the preferred embodiment of the invention as described above, the data storage system has the capability for storing both data that is being currently used and for data that is due to become effective at a predetermined time. By examining both the effective date fields 136 and 138 of the page zero record 132 and the change fields 210 in the records 182, 184, 186 and 188 of Fig.
5, the system can determine whether the data being retrieved is effective or not. This is accomplished by comparing the actual date as provided by the navigation system 38 with the effective dates 136 and 138. If the change bit 210 indicates that there is a change in the data, the present date must be compared to the data change 138 to determine which record should be used to provide the data for the identified navigation point. In this manner it is possible to store data for two different periods simultaneously and have the system automatically select the effective navigation data without operator assistance.
Due to the fact that navigation data is updated every 28 days, it is extremely important for the via-bility of a data base system that is being used with an alrborne navigation system to provide a convenient way for updating the data base. This is accomplished in the preferred embodiment of the invention by pro~iding a removable memory module 3~ as illustrated in detail in Fig. 6 in conjunction with a data interface unit 28.
The interface unit 28 is typically installed in a semi-permanent installation in the electronics bay of an aircraft and connected by means of line 36 to a navigation system such as the navigation system 38 shown in Fig. 1 along with a source of power over line 60. In order to promote the convenient removal of the memory module 32 from the interface unit 28 a latching mechanism is provided that includes a T-handle 236 connected to a shaft 238. In Fig. 6 the memory module is shown as having been removed from the interface unit 28. As may be appreciated from Fig. 6 the memory module 32 normally slides into a receptical portion 240 of the interface unit 28. The memory module 32 is guided into the rec~ptical 42 and by guide pins 242 and 244. An opening 246 in the housing 248 of the inter-face unit 28 is provided so that the coxrect seating of the memory module in the interface unit can be observed.
The housing 248 of the interface unit is preferably a standard size such as a one-quarter ATR short box.
A memory module includes a housing having two substantially symetrical parts 250 and 252. In Fig. 7 which is taken along lines 7-7 of Fig. 6 the bottom portion 250 of the memory module 32 housing is shown.
Enclosed within the lower part of the housing 250 is a circuit board 254 secured to the bottom half of the housing 250. On the under half of the circuit board and therefore not shown in Fig. 7 are located the magnetic bubble memory unit 70 and its associated electronic components. A connector 256 is located on 'he circui-t board 254. In addition to shaft 238 and T-handle 236, the latching mechanism for retaining the memory module 32 within the housing 248 of the update unit 28 includes a d~us fas-tener 258 on the end of the shaft 238. By rotating the T-handle 236 into a position as shown in Fig. 6, the dzus fastener is detached from a receptical in the housing 248 and the memory module 32 is easily extracted. Thus by just a twist of the wrist it is possible to remove the memory module from the interface unit which is very convenient for pilots wishing to update their data base.
In Fig. 8 is shown a front view of the circuit board 254 showing the various electronic components.
Included on the circuit board is a magnetic memory module 70 and a memory controller circuit 78. Also connected to the circuit board 254 is a connector 260 which mates with a corresponding connector (not shown) in the housing 248 of the interface unit 28. When the memory unit 32 is assembled and both halves 250 and 252 of the housings are secured together as shown in Fig. 6, the connector 256 will mate with a similar connector on a very similar memory board secured within the other half 252 of the memory module housing 32.
One very significant advantage of using magnetic bubble memories is that they are non--volatile and do not require power to maintain the data in the memory as do most semiconductor memories.
T~chnical Field The invention relates to the field of onboard aircraft navigation systems and, in particular, to data bases associated with such navigation systems contalning data relating to navigation aids and points.
Background of the Invention In order to obtain relevant information about navigation aids such as position and frequencies along with information about airport runways and outer markers, the pilot has typically had to consult a large number of charts or other paper publications. Because these charts and publications are usually bulky and hard to handle, problems are quite often created in the limited space of a cockpit. In addition it can taXe valuable time to find the appropriate navigational aid and its associated data on a chart or in a printed publication.
There have been a number of attempts to integrate data bases holding a large amount of information about navigation aids in aircraft navigation sys~emsO However, the amount of data that can be storecl has been limited due to the relatively small amount of data storage available in semiconductor memories. Alternatively mass storage devices such as disc memories have been proposed for st~ring the navigation information. One such sy~tem is disclosed in Hendrickson U.S. Patent 4t220,~4. ~owever~
mechanically based memories as shown in Hendrickson are no~
always the most appropriate for use in aircraft, especially corporate type aircraft d~e to space limitations and the requirement for reliabili~y.
In addition to being readily available, it i5 extremely important that the data base used in an aircrat navigations system be easily updated since information published by official government sources relating to navigation aids is typically updated at periodic intervals, usually every 28 days.
Summary of the Invention It is therefore an object of the invention to provide a data base for aircraft navigation systems that includes an electronic memory having at lea~t 2000 data records where each of the data records contains data relating to navigation points including the individual navigation point identifier and location coordinates, the capability for accessing one of the records having data relating to a particular navigation point utilizing the identifier for that point; a way of periodically updating the navigation point data in the electronic memory; and an interface for connecting the electronic memory to an airborne navigation computer.
It is an additional object of the invention to provide a data base for aircraft navigation systems that includes at least one magnetic bubble memory having a memory area divided into a predetermined number of data pages and where a group of the data pages are divided into data records that includes navigation data and the identifier for a navigation point and a controller circuit for operatively controlling the magn~tic bubble memory.
It is a further object of the invention ~o provide a removable memory module for use with a data interface unit of an aircraft navigation syst~m having a housing adapted to be received within the data int~rface unit;
at least one circuit board including a hulk electronic memory secuxed within the housing; an electrical connector connected to the printed circuit board and adapted to connect with the connector in the interfac-unit; and a latch for releasably securing the housing to the in~erface unit.
Brief Description of the Drawings Fig. 1 is a block diagram of an aircraft airborne navigation system utilizing a data base containing navigational point information;
Fig. 2 is a block diagram of an aircraft airborne navigation data base circuit;
Fig. 3 is a block diagram of a data update unit circuit;
Fig. 4 is a graphical representation of data page formats for use within an aircraft navigation data base;
Fig. 5 is a graphical representation of record formats for use with the data record pages of Fig. 4;
Fig. 6 is a perspective view of a data interface unit incluaing a removable memory module;
Fig. 7 is an interior view of the memory module taken along lines 7-7 of Fig. 6; and Fig. 8 is a view of a circuit board including a magnetic bubble memory for use in the memory module of Figs. 6 and 7.
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Detailed Description of the Invention -In Fig. 1 illustrated in block diagram fcrm is an aircraft navigation system util:izing a data base containing information relating to various navigational aids and navigational points. As shown in Fig. 1, a magnetic tape is received from a source such as the Jeppsen Company or other sources such as the ~nited States or other governments containing navigation information for various navigation aids or navigation points such as VOR-DME, nondirectional ~eacons, waypoints and airport information including the position of the airport along with the positions of the airport's outer markers and runways. Typically, the data on the magnetic tape 10 is formatted in accordance with ARINC Specifica-tion 424 as published by Aeronautical Radio, Inc., ofAnnapolis, Maryland.
As indicated by the dashed line 12, the magnetic tape 10 is received and used as an input to ~ data converter 14, which can be any conventional type of data processing equipment such as a Digital Equipment Corporation PDP-ll, and converts the data contained on the tape 10 into a format acceptable for input into an airborne navigation data base. This data format is discussed in detail in connection with Figs. 4 and 5.
The reformatted data is then output by the data converter 14 to a magnetic tape cartridge 16 as indicated by the dashed line 18 which in turn is utilized as an input, as indicated by the dashed line 20 to an update unit 22.
The tape cartridge 16 is inserted into a slot 24 in the data update unit 22.
Also inserted into another receptical 26 is a memory module 32 as indicated by the dashed line 30 Navigation data from the tape cartridge 16 is then .
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transferred by the update unit 22 to the memory module 32 which is plugged into the slot 26 of the up~ate unit as indicated by dashed line 30.
When the navigation data has been completely transferred to the memory module 32, the memory module 32 is removed from the receptical 26 in the update unit 22 and inserted in~o an interface unit 28 in the aircraft.
Equipment that is installed in the aircraft is indicated in Fig. l by means of the dashed line 34. In the aircraft, the update unit is electrically connected by means of a cable 36 to an airborne navigation system 38. In the preferred embodiment of the invention, the airborne navigation system is a GNS 500A Series 3 VLF/Omega aircraft navigation system sold by Global Navigation, Inc. As shown in Fig~ l, the control display unit (CDU) is connected directly to the interface unit 28 by the cable 36. Included in the navigation system CDU 38 is a cathode ray tube display 40 for displaying various types of navigation information of the type stored in the memory module 32 and an alpha-numeric keyboard 42 for entering data, requesting types of data, and control-ing the navigation system.
In Fig. 2 of the drawings is a block diagram of the electronic circuits contained within the interface unit 28 which are generally indicated as being within the dashed lines 44 and a block diagram of the electronic circuits contained in the memory module 32 as indicated by the dashed lines 46.
Included in the interface unit circuitry 44 is a microprocessor 48 connected by means of a line 50 to a read only memory 52 that contains a program for control-ling the operation of the microprocessor 48. Also connected to the microprocessor 48 by means of line 54 is a random access memory 56 for the temporary storage of data that is either being input or out:put through the interface unit 44. A power supply 58 is al50 included in the interface unit circuit 44 and is connec~ed ~y means of a line 60 to a power source in the aircraft. Vata is received from the navigation system 38 over lines 36 by means of a buffer circuit 52 that is in turn connected to the microprocessor 48 by lines 64 and 660 When the memory module 32 is inserted in the interface unit 28, the microprocessor 48 is connected to the circuit board 48 of the memory unit 46 by means of a connector ~8.
In the preferred embodiment of the invention, the memory module 36 contains two magnetic bubble memories 70 and 72. The preferred magnetic bubble memory is an Intel 7110 one megabit bubble memory sold by Intel Corpora~ion of Santa Clara, California. Each of the magnetic bubble memories 70 and 72 are organized into 2048 pages with 512 bits per pageO Operation of the magnetic bubble memories 70 and 72 and associated circuits is described in detail in the Intel Corporation publication entitled BUBBLE MEMORY DESIGN ~ANDBOOK. Connected to each of the magnetic bubble memory units 70 and 72, by means of data lines 74 and 76, is a bubble memory controller circuit 78.
As with the magnetic bubble memory units 70 and 72, the preferred controller circuit is an Intel 7220 which is also described in detail in the above referenced Intel publication. The memory module circuit 47 a].so includes a five volt voLtage regulator 80 connected to the controller 78 by means of line 82. An oscillator 84 is connected to the magnetic bubble memory 70 and 72 by means of a line 88.
When the memory module 32 containing the circuit 44 i5 secured within the interface unit 28, the controller 78 is connected to the microprocessor 48 by means of connector 68.
Incl~ded in the connector 68 between the controller 78 and the microprocessor 48 are at least eight data lines indicated at 90 along with an interrupt line 92 a~d a data transfer request line 94, a read line 96 and a write line 98. Utilizing the control lines 92, 94, 96 and 98, the microprocessor 48 can control the navigation data flow from and to the controller 78 over data lines 90.
Power is supplied to the controller 78 from the voltage regulator 80 by means of line ~9. Power line 99 also goes to the oscillator 84 and bubble memories 70 and 72. One of the significant features of the invention is ~hat power is only applied to the bubble m~mories 70 and 72 when a request for data has been init:iated thereby substantially reducing the heat produced by the memories 70 and 72. When a request for data is received by the microprocessor 48, a signal is transmitted over line 97 to the power supply 58 which in turn applies power to the controller 78 over line 99 thru voltage regulat~r 80O In order to accommodate successive req~ests for data the microprocessor will cause the power supply 58 to maintain power to the memory module circuit 46 for a predetermined amount of time such as four seconds.
In Fig. 3 is provided a block diagr~m of the circuit used in the update unit 22. Included in the update unit circuitry is a microprocessor 100 which in the preferred embodiment of the invention is of the ame type as the microprocessor 48 in the interface unit circuit 44. The memory module 32 when inserted in the update unit 22 ls connected electrically by means of a connector 102. The lines connecting the memory module 32 to the micro-processor 100 are substantially the same as the lines connecting the microprocessor 48 to the controller 78 as shown in Fig. 1 including the parallel data lines 90. In addition, the update unit includes a power supply 104 that is connected to the microprocessor 100 by a line 106 and to the memory module 3~ by means of a line 108 through the connector 102. The update unit 22 also inc~-u~es a tape transport 110 whlch receives the magnetic tape cassette 16 when it is inserted into the slot 26 of the update unit 22 as shown in Fig. 1. A controller circuit 112 controls the tape transport 110 and the navigation data is transmitted over line 114 through the controller to the microprocessor 100 over ~ine 116.. The power supply 104 provides power to both the tape transport 110 and the controller 112 over a line 118. In operation when the tape cassette 16 is inserted into the update unit 22, the tape transport will read the magnetic tape cassette and transfer the navigation data to the microprocessor 100 which in turn will transmit the navigation data over data lines 90 to the memory module where it is loaded into the magnetic bubble memories 70 and 72.
The update unit in addition includes an interface board 120 that serves to control a display unit 122 by means of a line 124 and a set of input switches 126 by means of a line 128. The input switches 12~ can be used by an operator to set an address of a particular page in the memory module 32 and the interface board will cause the microprocessor by means of line 130 to access that particular page having that address and return a predetermined portion of the contents of that page through the interface board to the display 122. As a result, predetermined portions of contents of various pages with the memory module 32 can be checked~ In one type of operation each tape cassette 16 with new navigation data base information to be loaded into the memory module 32 is accompanied by a sticker with several addresses and the contents of a portion of the pages with those addresses printed thereon in order to provide an operator with an opportunity to test that the correct da~a is being loaded into the memory module 3~.
3~
g Since one of the ~.ost important objects of the invention is to provide for efficient storage and retrieval of the maximum amount of navigational data possible, the organization of the da~a within the magnetic ~ubble memories 70 and 72 is important. rn order to illustrate the preferred manner in which the data is stored within the magnetic bubble memories 70 and 72, Figs.
4 and 5 are provided to illustrate the manner in which the pages are organized along with the organization of the records within the pages. In a memory module 32 having two magnetic bubble memory units 70 and 72, there are 4096 pages of data available where each page contains 64 bytes or 512 bits of information. The pages are numbered zero to ~095 and are identiEied by a 12-bit address and are ordered sequentially. The data stored in the memory module 32 is compressed into binary form and the records are organized into a:Lpha-numeric order with all the record types and geographical areas inter-mixed. The alpha-numerical ordering is based on the identifier for each navigation aid or navigation point.
In order to minimize the space required for each record, each type of record has a slightly modified format so that varying types of information such as~latitude and longitude, frequency and station declination can be stored efficiently. As described more completely in connection with FigO 5, the records are yrouped into 64-byte pages with labels and check sums added.
As illustrated in Fig. 4, the first type of page 132 is located at page number zero and contains basic information with respect to the organization of ~he data in magnetic bubble memories 70 and 72. The first byte 134 consists of a label identifying t:he type of page along with miscellaneous flags. Information with respect to the effective date of the navigational data stored within the memory is contained within the second record area 136 and the effective date of any change inform~ivn is contained within the third record area 1380 In the four~h record area 140, the start addresses of sub-records are 5 stored and in the fifth record 14~, the start addresses of req.~elev. records are stored. Start addresses o the country name list are stored in ~he sixth record area l44 and the start address of the Airway ID list are stored in the seventh record area 146. The stop address of the Airway ID list is stored in record area 148. The rest of the record areas and the page 132 are not used in the preferred embodiment except for the two last bytes 150 which are ~sed to store a check sum.
The structure of the basic record page 152 is illustrated in Fig. 4. As with each of the other pages, the first byte 154 is used to store label information and the second byte 156 is not used at present. The remainder of the page 152 is divided into six 10-byte records 160 through 168 along with two bytes of check s~ data 170 and 1720 The third basic type of page ut:ilized in the magnetic bubble memory 70 and 72 is the sub-record page 174 which includes a label byte 176~ twenty sub-records R1 through R20 each of which is three bytes in length and two bytes of check sum 178 and 180.
In Fig. 5 are illustrated the various record formats that appear in the basic record page 152 of Fig.
4. There are four basic record formats: the VHF navi-gation aid 182 such as VOR-D~E; a nondirectional beacon 184; a waypoint 186; and an airport 188. Each record format is used to store data for a particular type of navigation point or aid. In each one of these records, ~3~
17 bits in a first field 190 is used to store the latitude of the navigation point and an 18-bit field 192 is ~sed to store the longitude of the navigation pointO Each of the basic records 182, 184, 186 and 188 also includes a label field 194, 196, 198 and 20Q to identify the type of record since each type of record has a somewhat different forma~
and the rec~rds are intermixed. Additionall~, the label fields 194, 19~, 198 and 200 indicate if there are any adjacent ambiguous identifiers. An ambiguous identiEier results when more than one navigation point has the same identifier. For example, there are a number of VOR stations located in different countries that have the same identifier. Each of the record types also has a field for storing the identifier for that particular navigation point. For the VHF navigations aid 182, a field 202 21 bits long is used to store an identifier of up to four alpha-numeric characters and the nondirectional beacon record 184 utilized a 27-bit field 204 to store an identifier of up to five alpha-numer:ic characters.
Similarly the waypoint record 186 utilizes a 27~bit field 206 to store a five letter identifier and the airport record 188 utilizes a 21-bit field to store an identifier of up to four alpha-numeric characters. In cc~nvertiny the alpha-numeric identifier into binary representation for storage in the identification fields 202, 204, 206 and 208, each identifier character is converted into a number from zero to 37 which in turn is stored in a binary representation in the appropriate label field 194, 196, 198 or 200.
Each of the basic records 182, 184, 186 and 188 also includes one bit 210 that indicates whether or not the change list for that particular navigation point is 3~
in effect. The VHF navigation aid record 182 also includes a bit that indicates whether or not ~he DME is located greater than a predetermined dista~ce from the VOR antenna. In some instances, the DME ante~na can be located as far as one-half mile from the ~GR ~ntenna and therefore will have a significantly different position as defined in latitude and longitude. ~ field 214 is also included in the record 182 t:o provide an indication of the magnetic variation of the navigation aid.
The nondirectional beacon record 184 includes a nine-bit field which provides the radio frequency of the beacon.
The airport record 188 inc:Ludes a field 218 that is used to store the starting address of the sub-records as sho~n in the sub-record page of Fig. 4. ~s shown in Fig. 5, a sub-record 220 includes an identification field 222 and a delta latitude field 224 and a delta longitude field 226. The starting address for the airport sub-record 220 will define both the page and the number of the record in that page so the beginning sub-record for that airport can be located directly. The identification field 222 of the sub-record indicates the nature of the point belng specified such as an outer marker or the number of a runway. The delta latitude and delta longitude fields 224 and 226, respectively, are combined with the value of latitude and longitude stored in the airport record 188 to get the exact position in latitude and longitude of the specific position contained in the sub-record 210.
The last signific~nt type of record utili~ed in the memory module 32 is a continuation record 228 that is used to store the same kind of information as in the other four major records 182, 184, 186 and 188 when there is an ambiguous identifier such that t~o or more naviga-tion points have the same identifier. Stored in an identifier field 230 is an international identiEier specified by ICAO that unambiguously identifies the navigation point. In addition to the identifier field 230, the continuation record includes a label Jield 232 to identify the type of record and a record field 234 that matches the appropriate record fields in one of the basic four records 1~2, lg4, 1~6 and 188.
With reference to the sub-record 220 in Fig~ 5, it should be noted that in order to provide complete information with respect to the identifier stored in the first field 222 which is only one-byte or eight-bits long, it is necessary to compress the data representing the ID. To utilize, for example, the first bit to indicate whether the record is representing an outer marker or a runT~ay and the second bit to indicate whether the outer marker is right or left with the other six bits remaining to indicate the outer marker or runway number does not provide for all the possible types o~ outer markers or runways. For example, in addition to right and left outer markers and runways~
there are in some cases center runways with center outer markers and in the cases where there is only a single runway there will be only a single outer marker. There-fore, there are six different combinations of outer markers and runways that need to be stored in the record 220.
In the preferred embodiment of the invention this is compensated for by assigning a number from one to six to the type of runway or outer marker and multiplying that designator by 35 and adding ~he runway number. This combination can then be stored in the ID field 222 in the existing eight bits. To decode the label, the identifier field 222 is divided by 36 to get an integer that represents the type of navigation point and the remainder will be the runway or outer marker number.
In a typical operation of a navigation system in conjunction with the navigation data base a pilot will select a navigation point for display nn the CRT 40 of the control and display unit of the navigation system 38 by entering the identifier by means of the alpha~numeric keyboard 42. Thls identifier is then transmitted by means of lines 36 through the buffer S2 of the interface module under control of the microprocessor to the controller 78 of the memory module 46 as shown in Fig. 2. Since the records 156 through 168 and the record pages 152 are stored in alpha-numerical order, one method of quickly accessing the relevant record is to perform a binary search on the record pages. The first step of the search is to fetch, under control of the microprocessor 48, the record page 152 that is approximately one-half way through the number of record pages. As indicated previously, the beginning and ending addresses of the record pages 152 are stored in the ~ero pase 132 so that the number of the pa~e halfway through the record page group is easily determined. The identifier of the navigation point to be selected is then tested against one of the identifiers of the selected record and if there is a match the pertinent information is transmitted back to the navigation system 38~ In a typical navigation system, such as the one described in connection with the preferred embodiment of the invention, there will be a number of storage locations where up to 127 navigation points can be stored in the navigation system 38 itself for immediate use by the navigation system. For example, many navigation systems set up flight plans with a series of waypoints and it is convenient to store the p*rtinent facts such as the position and frequencies of various waypoints and navigation aids directly in the navigation syste~ itself.
In the event a match is not found in the first comparison and the identifier being so~ght is higher than the one tested against, the microprocessor 48 will cause the controller 78 to fetch a record page that is approximately three-quarters of the way through the whole groJp of record pages. If the desired identifier i6 greater than the identifier of the record selected, then the microprocessor 48 will cause the controller to select a record page 152 which is approximately one-quarter of the way from the first record page. A comparison is then made and, if the desired record page is not found at this poin~, the same process is repeated until the desired record page is found. Since the binary search is usually successful in locating the appropriate page within eleven fetches, the record containing the desired navigation data can be located quickly enough to appear almost instantaneous to the operator. In this manner, a desired navigation point having a predetermined identifier can be rapidly selected from among the over 4000 record pages in the magnetic bubble memory 70 and 720 It should be also noted that the continuation records 228 that have the same identifiers as other records are located adjacent to the records with the same identifier. When a match is found with the desired identifierl the microprocessor 48 will cause the controller to produce adjacent records for examination~ In the preferred embodiment of the invention, one technique to identify the pertinent navigation points when more than one identifier is found is to compaee the present position of the aircraft as transmitted by the naviga-tion system 38 to the microprocessor 48 with each of the positions of the navigation aids found. Under the assumption that navigation aids with th~ sa~e iderltifier are usually located on different continents~ it is assumed that the person or system requesting the navigation poin~ is interested in the closest one.
As indicated before, navigation data is typically updated periodically, usually every 28 days, by the various authorities that publish the navigation data.
In the preferred embodiment of the invention as described above, the data storage system has the capability for storing both data that is being currently used and for data that is due to become effective at a predetermined time. By examining both the effective date fields 136 and 138 of the page zero record 132 and the change fields 210 in the records 182, 184, 186 and 188 of Fig.
5, the system can determine whether the data being retrieved is effective or not. This is accomplished by comparing the actual date as provided by the navigation system 38 with the effective dates 136 and 138. If the change bit 210 indicates that there is a change in the data, the present date must be compared to the data change 138 to determine which record should be used to provide the data for the identified navigation point. In this manner it is possible to store data for two different periods simultaneously and have the system automatically select the effective navigation data without operator assistance.
Due to the fact that navigation data is updated every 28 days, it is extremely important for the via-bility of a data base system that is being used with an alrborne navigation system to provide a convenient way for updating the data base. This is accomplished in the preferred embodiment of the invention by pro~iding a removable memory module 3~ as illustrated in detail in Fig. 6 in conjunction with a data interface unit 28.
The interface unit 28 is typically installed in a semi-permanent installation in the electronics bay of an aircraft and connected by means of line 36 to a navigation system such as the navigation system 38 shown in Fig. 1 along with a source of power over line 60. In order to promote the convenient removal of the memory module 32 from the interface unit 28 a latching mechanism is provided that includes a T-handle 236 connected to a shaft 238. In Fig. 6 the memory module is shown as having been removed from the interface unit 28. As may be appreciated from Fig. 6 the memory module 32 normally slides into a receptical portion 240 of the interface unit 28. The memory module 32 is guided into the rec~ptical 42 and by guide pins 242 and 244. An opening 246 in the housing 248 of the inter-face unit 28 is provided so that the coxrect seating of the memory module in the interface unit can be observed.
The housing 248 of the interface unit is preferably a standard size such as a one-quarter ATR short box.
A memory module includes a housing having two substantially symetrical parts 250 and 252. In Fig. 7 which is taken along lines 7-7 of Fig. 6 the bottom portion 250 of the memory module 32 housing is shown.
Enclosed within the lower part of the housing 250 is a circuit board 254 secured to the bottom half of the housing 250. On the under half of the circuit board and therefore not shown in Fig. 7 are located the magnetic bubble memory unit 70 and its associated electronic components. A connector 256 is located on 'he circui-t board 254. In addition to shaft 238 and T-handle 236, the latching mechanism for retaining the memory module 32 within the housing 248 of the update unit 28 includes a d~us fas-tener 258 on the end of the shaft 238. By rotating the T-handle 236 into a position as shown in Fig. 6, the dzus fastener is detached from a receptical in the housing 248 and the memory module 32 is easily extracted. Thus by just a twist of the wrist it is possible to remove the memory module from the interface unit which is very convenient for pilots wishing to update their data base.
In Fig. 8 is shown a front view of the circuit board 254 showing the various electronic components.
Included on the circuit board is a magnetic memory module 70 and a memory controller circuit 78. Also connected to the circuit board 254 is a connector 260 which mates with a corresponding connector (not shown) in the housing 248 of the interface unit 28. When the memory unit 32 is assembled and both halves 250 and 252 of the housings are secured together as shown in Fig. 6, the connector 256 will mate with a similar connector on a very similar memory board secured within the other half 252 of the memory module housing 32.
One very significant advantage of using magnetic bubble memories is that they are non--volatile and do not require power to maintain the data in the memory as do most semiconductor memories.
Claims (46)
1. An airborne data base system to store the identifier and navigation data for a plurality of navigation points for aircraft navitation comprising:
an electronic memory located in the aircraft;
memory means located in the aircraft for dividing said electronic memory into a predetermined number of addressable pages and including means for dividing each of a plurality of said addressable pages into record areas wherein a predetermined number of said record areas are defined as navigation point records and wherein each said navigation point record contains the navigation data and the identifier for an individual navigation point; and a controller circuit located in the aircraft operatively connected to said electronic memory for address-ing each of said addressable pages.
an electronic memory located in the aircraft;
memory means located in the aircraft for dividing said electronic memory into a predetermined number of addressable pages and including means for dividing each of a plurality of said addressable pages into record areas wherein a predetermined number of said record areas are defined as navigation point records and wherein each said navigation point record contains the navigation data and the identifier for an individual navigation point; and a controller circuit located in the aircraft operatively connected to said electronic memory for address-ing each of said addressable pages.
2. The system of claim 1 wherein said memory means includes means for creating a control page from one of said predetermined number of addressable pages for storing data relating to the contents and location of said addressable pages.
3. The system of claim 2 wherein said memory means includes means for creating a plurality of sub-record pages from said predetermined number of addressable pages.
4. The system of claim 3 wherein said memory means includes means for ordering said navigation point records in an alpha-numeric sequence of the navigation point identifiers contained in said navigation point records and for providing said addressable pages in alpha-numeric order such that the navi-gation point records are effectively stored in said electrc)nic memory in the alpha-numeric sequence of the nagivation point identifier.
5. The system of claim 4 including means for storing data for more than one type of navigation point in said navigation point records and wherein at least a portion of said navigation point records includes a label indicating the type of navigation point;
the identifier for the navigation point; and a bit representation of the latitude and longitude of the geographical location of the navigation point.
the identifier for the navigation point; and a bit representation of the latitude and longitude of the geographical location of the navigation point.
6. The system of claim 5 wherein one of said types of navigation points is a VOR navigation point having a VOR antenna and a DME antenna and wherein a predetermined number of said navigation point records contain data for said VOR navigation points and include a flag bit indicating whether or not the position of the VOR antenna at the VOR
navigation point varies from the DME antenna by a pre-determined amount.
navigation point varies from the DME antenna by a pre-determined amount.
7. The system of claim 6 wherein said predetermined navigation point records containing VOR navigation points additionally include the frequently of the VOR and the magnetic variation of the VOR.
8. The system of claim 3 wherein the navigation points include airports having outer markers and runways and wherein said sub-record pages include a predetermined number of sub-record areas that include data for an individual airport that represents the location of outer markers and airport runways for that airport.
9. An airborne data base system for aircraft navigation comprising:
an airborne electronic memory for storing data relating to navigation points;
an airborne power supply operatively connected to said electronic memory;
an airborne navigation computer, operatively connected to said electronic memory and said power supply, means, operatively connected to said airborne navigation computer and said power supply for applying power from said power supply to said electronic memory in response to a request for navigational data from said airborne navigational computer to said electronic memory and for disconnecting said power approximately four seconds after said request for navigational data.
an airborne electronic memory for storing data relating to navigation points;
an airborne power supply operatively connected to said electronic memory;
an airborne navigation computer, operatively connected to said electronic memory and said power supply, means, operatively connected to said airborne navigation computer and said power supply for applying power from said power supply to said electronic memory in response to a request for navigational data from said airborne navigational computer to said electronic memory and for disconnecting said power approximately four seconds after said request for navigational data.
10. The system of claim 9 wherein said electronic memory is non-volatile.
11. An airborne data base system for aircraft navigation comprising:
11. An airborne data base system for aircraft navigation comprising:
Claim 11 cont d ....
an electronic memory including a plurality of navigation point records wherein each of said navigation point records stores navigation point data for a navigation point including an identifier that identifies the navigation point stored in the navigation point record, and means, operatively connected to said electronic memory, for selectively accessing one of said naviyation point records storing navigation point data for a predetermined navigation point utilizing the identifier for said predetermined navigation point.
an electronic memory including a plurality of navigation point records wherein each of said navigation point records stores navigation point data for a navigation point including an identifier that identifies the navigation point stored in the navigation point record, and means, operatively connected to said electronic memory, for selectively accessing one of said naviyation point records storing navigation point data for a predetermined navigation point utilizing the identifier for said predetermined navigation point.
12. The system of claim 11 additionally including means for periodically updating said navigation point data in said electronic memory that includes means for providing said navigation point records for two different time periods and means for automatically selecting the appropriate navigation point record associated with said predetermined identifier for a date within one of said time periods.
13. The system of claim 12 additionally including an interface means, operatively connected to said electronic memory, configured for transmitting said navi-gation point data to an airborne navigation computer on the aircraft.
14. The system of claim 11 wherein said navigation point records are ordered in said electronic memory in an alpha-numerical sequence of said identifiers.
15. The system of claim 14 wherein said navigation point records include fields for storing the longitude and latitude of the navigation point.
16. The system of claim 15 wherein said navigation point records includes a label field for storing a navigation point type indication.
17. The system of claim 12 including means for providing in said navigation point records an indication of whether a change date for the particular navigation point data stored in the navigation point record is in effect.
18. The system of claim 14 including means for structuring said navigation point records in a plurality of different formats.
19. The system of claim 18 wherein a first of said formats is for VHF navigation aids, a second of said formats is for a non-directional beacon, a third of said formats is for a waypoint and a fourth of said formats is for an airport.
20. The system of claim 19 including means for providing a plurality of sub-records for storing position data for an airport related specified point wherein each of said sub-records includes a field indicating the nature of the point being specified for the airport.
21. The system of claim 20 where at least one of said fourth format navigation point record includes a field containing the starting address in said electronic memory of one of said sub-records associated with the said fourth navigation point record.
22. The system of claim 11 wherein said accessing means includes means for automatically selecting said pre-determined navigation point when there is more than one navigation point having the same identifier,
23. The system of claim 22 wherein said automatic selecting means includes means for comparing the position of the navigation points in said accessed navigation point records to the position of the aircraft and means for selecting the navigation point record having the position closest to the aircraft.
24. The system of claim 11 wherein said navigation point records include an ambiguous identifier indication for those navigation points having ambiguous identifiers.
25. The system of claim 24 wherein said electronic memory additionally includes continuation records for said navigation points having an ambiguous identifier for storing the navigation point data for those navigation points having the ambiguous identifier.
26. The system of claim 25 wherein said accessing means includes means for automatically selecting said predetermined navigation point when there is more than one navigation point having the same identifier.
27. The system of claim 26 wherein said automatic selecting means includes means for comparing the position of the navigation points in said accessed navigation point records to the position of the aircraft and means for selecting the navigation point record having the position closest to the aircraft.
28. The system of claim 11 including means for storing an effective date of said navigation point data in said electronic memory.
29. The system of claim 28 including means for storing a change date of information relating to said navigation point data in said electronic memory.
30. The system of claim 29 wherein said electronic memory includes two said navigation point records for a single navigation point and wherein each of said two navigation point records stores navigation point data for a different time period and wherein at least one of said two navigation records includes a change indication.
31. The system of claim 30 wherein said electronic memory includes a change date representing the beginning date of the second of said two different time periods.
32. The system of claim 11 wherein at least a portion of the navigation point data for a single navigation point stored in said navigation point records is for two different time periods; and wherein said access means includes selection means for automatically selecting that portion of said navigation point data relating to a predetermined one of said two different time periods.
33. The system of claim 32 wherein a change date indicating the beginning of one of said time periods is stored in said electronic memory; and said selection means include means for determining the actual date, comprising means for comparing said actual date to said change date, and means responsive to said comparing means for retrieving the navigation point data relating to one of said two different time periods as indicated by the actual date.
34. The system of claim 31 wherein said access means performs a binary search on said identifiers in accessing said one of said navigation point records.
35. An airborne aircraft navigation system com-prising:
navigation computer located on the aircraft;
an electronic memory located on the aircraft including a plurality of navigation point records wherein each of said navigation point records stores navigation point data including an identifier that identifies the navigation point for which said data is stored in the navigation point record;
accessing means located on the aircraft operatively connected to said electronic memory, for selectively accessing one of said navigation point records relating to a predetermined navigation point utilizing the identifier for said predetermined navigation point;
means located on the aircraft for periodically updating said navigation point data in said electronic memory; and interface means, located on the aircraft operatively connected between said electronic memory and said navigation computer, for transmitting said navigation point data to said navigation computer.
navigation computer located on the aircraft;
an electronic memory located on the aircraft including a plurality of navigation point records wherein each of said navigation point records stores navigation point data including an identifier that identifies the navigation point for which said data is stored in the navigation point record;
accessing means located on the aircraft operatively connected to said electronic memory, for selectively accessing one of said navigation point records relating to a predetermined navigation point utilizing the identifier for said predetermined navigation point;
means located on the aircraft for periodically updating said navigation point data in said electronic memory; and interface means, located on the aircraft operatively connected between said electronic memory and said navigation computer, for transmitting said navigation point data to said navigation computer.
36. The system of claim 35 wherein said navigation computer includes a keyboard effective to permit an operator to access, by means of said access means and said inter face means, said data for said predetermined navigation point wherein said identifier for said predetermined navigation point is entered into said computer via said keyboard.
37. The system of claim 36 wherein said navigation computer includes display means for displaying at least a portion of said navigation point data for said predetermined navigation point.
38. The system of claim 37 wherein said navigation computer includes a plurality of memory elements for temporarily storing said navigation point data accessed from a plurality of said navigation point records such that data from more than one navigation point is available for immediate display on said display.
39. The system of claim 38 wherein said navigation computer utilizes VLF/mega radio signals for navigation.
40. A data base system for use with an aircraft navigation system comprising:
a memory module located on the aircraft including record areas for storing data for a plurality of navigation points wherein each of said records areas stores data for one of the navigation points;
an interface unit located on the aircraft adapted for installation in an aircraft, configured so as to permit the physical insertion of said memory module in said interface module; and an update unit adapted for connection to said memory module and including circuit means for transmitting said data from said update unit to said memory module when said memory module is connected to said update unit.
a memory module located on the aircraft including record areas for storing data for a plurality of navigation points wherein each of said records areas stores data for one of the navigation points;
an interface unit located on the aircraft adapted for installation in an aircraft, configured so as to permit the physical insertion of said memory module in said interface module; and an update unit adapted for connection to said memory module and including circuit means for transmitting said data from said update unit to said memory module when said memory module is connected to said update unit.
41. The system of claim 40 wherein said interface unit includes a circuit adapted for connection to an airborne navigation system and effective to transmit said data from said memory module to an airborne navigation system when said memory module is inserted in said interface unit.
42. The system of claim 41 additionally including data conversion means operatively connected to said update unit for converting said data in a first format received from a data input source into a second format suitable for storage in said memory module record areas and for storing said data in said second format in an update unit data memory.
43. The system of claim 40 wherein said memory module includes at least one magnetic bubble memory organized into a predetermined number of pages wherein said pages include a plurality of record areas.
44. The system of claim 40 wherein said data interface assembly includes a microprocessor operatively connected to said memory module when said memory module is secured within said interface assembly and operatively connected to said interface means wherein said microprocessor is effective to control access to said navigation data within said memory module.
45. The system of claim 44 wherein said interface unit includes random access memory operatively connected to said microprocessor for temporary storage of small amounts of said data accessed from said memory module under control of said microprocessor.
46. The system of claim 40 wherein said update unit includes a microprocessor operatively connected to said data memory and said circuit means;
means operatively connected to said microprocessor for selectively accessing one of said record areas when said memory module is secured to said update unit; and display means operatively connected to said microprocessor for displaying at least a portion of the record area accessed.
means operatively connected to said microprocessor for selectively accessing one of said record areas when said memory module is secured to said update unit; and display means operatively connected to said microprocessor for displaying at least a portion of the record area accessed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000472712A CA1204491A (en) | 1981-09-22 | 1985-01-23 | Data base for aircraft navigation system |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US30450981A | 1981-09-22 | 1981-09-22 | |
| US304,509 | 1981-09-22 |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000472712A Division CA1204491A (en) | 1981-09-22 | 1985-01-23 | Data base for aircraft navigation system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1194999A true CA1194999A (en) | 1985-10-08 |
Family
ID=23176830
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000411254A Expired CA1194999A (en) | 1981-09-22 | 1982-09-10 | Data base for aircraft navigation system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1194999A (en) |
-
1982
- 1982-09-10 CA CA000411254A patent/CA1194999A/en not_active Expired
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| MKEX | Expiry |