Clandestine location reporting by a missing vehicle

Claims

I claim:

1. Apparatus for determining and reporting the present location of a missing vehicle, the apparatus comprising:

a location determination (LD) unit, including an LD signal antenna and LD receiver/processor, positioned on the vehicle to receive LD signals from at least three distinguishable LD signal sources and to process these LD signals so that the processed signals can be used to determine the present location of the LD antenna;

a cellular phone unit positioned on the vehicle and comprising:

a cellular phone handset that receives audio signals at a first port and converts these audio signals to electronic signals and that receives electronic signals at a second port and converts these electronic signals to audio signals; and

a cellular phone radio transceiver and antenna that receives electronic signals at a signal port and transmits these signals as outgoing radiowave signals at a selected frequency to a central station that is spaced apart from the cellular phone transceiver, that receives incoming radiowave signals from the central station and issues these signals as electronic signals at the signal port, and that can generate and issue an audibly perceptible or visually perceptible incoming call signal that indicates when the radio transceiver and antenna is receiving an incoming radiowave signal intended for that transceiver, where the cellular phone transceiver and antenna are capable of receiving and responding to an LD interrogation signal from the central station that requests information on the present location of the LD antenna; and

a controller, positioned on the vehicle, connected to and selectively controlling and acting as an interface between the LD unit and the cellular phone unit, for passing signals between the LD unit and the cellular phone unit, wherein (i) when the cellular phone unit receives an incoming phone call, the controller causes the cellular phone unit to delay issuance of an incoming call signal for a selected initial time interval of length .DELTA.t.sub.d ; (ii) when the cellular phone unit receives an LD interrogation signal during an initial time interval of length .DELTA.t.sub.d as part of the incoming phone call, the controller causes the cellular phone unit not to issue an incoming call signal indicating receipt of an incoming call, causes the LD unit to provide the cellular phone unit with information on the present location of the LD antenna, and causes the cellular phone radio transceiver and antenna to transmit this present location information to the central station; and (iii) when the cellular phone unit does not receive an LD interrogation signal during an initial time interval of length .DELTA.t.sub.d as part of the incoming phone call, the controller causes the cellular phone unit to operate as a normal cellular phone and to issue an incoming call signal that is perceptible by an occupant of the vehicle.

2. The apparatus of claim 1, wherein, when said incoming phone call does not receive an LD interrogation signal during an initial time interval of length .DELTA.t.sub.d as part of the incoming phone call, said controller causes said cellular phone unit to issue an incoming call signal for said vehicle occupant, indicating receipt of an incoming call by said cellular phone unit, until said cellular phone unit goes off-hook or the calling party disconnects or the incoming call signal is issued a selected number of times.

3. The apparatus of claim 1, wherein at least one of said LD unit and said controller is hidden from view on said vehicle.

4. The apparatus of claim 1, wherein, when a vehicle occupant within the vehicle uses said cellular phone unit to communicate with an other person or facility at another location, said cellular phone unit operates as a normal cellular phone and allows the vehicle occupant to communicate with that other person or facility, if said cellular phone unit is not responding to said LD interrogation signal at the time the vehicle occupant uses said cellular phone unit.

5. The apparatus of claim 4, further comprising:

a recording switch having an active state and an inactive state; and

recording means, connected to said cellular phone unit and to the recording switch, for recording and storing at least one of (i) a contact phone number for an incoming call or outgoing call using said cellular phone unit and (ii) a voice communication, which uses said cellular phone unit, between said vehicle occupant and said other person or facility, when the recording switch is in its active state.

6. The apparatus of claim 5, wherein said recording means causes said cellular phone unit to transmit a recording advisory signal to said central station, indicating that said cellular phone unit has been used for an incoming call or outgoing call, if at least one voice communication or phone number has been recorded by said recording means.

7. The apparatus of claim 6, wherein said cellular phone unit is capable of receiving from said central station a recording interrogation signal, in response to receipt by said central station of said recording advisory signal, the apparatus further comprising stored message transmission means, connected to said recording means and to said cellular phone unit, for obtaining information on at least one of (i) said contact phone number and (ii) said voice communication, stored in said recording means, and for transmitting this information to said central station when said cellular phone unit receives a recording response command signal from said central station.

8. The apparatus of claim 1, further comprising a message storage memory, connected to said controller, wherein, when a vehicle occupant uses said cellular phone unit to communicate with an other person or facility at another location while said apparatus is receiving or is responding to said LD interrogation signal, said cellular phone unit will abort its response to said LD interrogation signal, will store said LD antenna present location information in the message storage memory, will operate as a normal cellular phone and will allow the vehicle occupant to contact the called person or facility, if said cellular phone unit is responding to said location interrogation signal at the time the vehicle occupant uses said cellular phone unit.

9. The apparatus of claim 8, wherein said controller further comprises stored message transmission means, for retrieving said LD antenna present location information from said message storage memory and for causing said cellular phone transceiver and antenna to transmit said LD antenna present location information to said central station, after said cellular phone handset has returned to an on-hook condition.

10. The apparatus of claim 8, wherein said cellular phone unit transmits an abort signal to said central station, if said cellular phone unit's response to said LD interrogation signal is aborted before this response is completed.

11. The apparatus of claim 1, wherein, when an occupant of the vehicle uses said cellular phone unit to communicate with an other person or facility at another location while said apparatus is receiving or is responding to said LD interrogation signal, said cellular phone unit will abort its response to said LD interrogation signal, will operate as a normal cellular phone and will allow the vehicle occupant to communicate with the other person or facility, if said cellular phone unit is responding to said location interrogation signal at the time the vehicle occupant uses said cellular phone unit.

12. The apparatus of claim 1, wherein, when an occupant of the vehicle uses said cellular phone unit to communicate with an other person or facility at another location while said apparatus is receiving or is responding to said LD interrogation signal, said cellular phone unit will complete the transmission of its response to said LD interrogation signal, will then operate as a normal cellular phone and will allow the vehicle occupant to communicate with the other person or facility, if said cellular phone unit is responding to said location interrogation signal at the time the vehicle occupant uses said cellular phone unit.

13. The apparatus of claim 1, wherein, when an occupant of the vehicle uses said cellular phone unit to communicate with an other person or facility at another location while said apparatus is receiving or is responding to said LD interrogation signal, said cellular phone unit will behave as if it is disabled so that the vehicle occupant will be unable to complete a phone call connection using said cellular phone unit, if said cellular phone unit is responding to said location interrogation signal at the time the vehicle occupant uses said cellular phone unit.

14. The apparatus of claim 1, wherein said time interval length .DELTA.t.sub.d lies in the range of about 0.2-30 sec.

15. The apparatus of claim 1, wherein said time interval length .DELTA.t.sub.d lies in the range of about 1-5 sec.

16. A method for determining and reporting the present location of a missing vehicle, the method comprising the steps of:

providing a location determination (LD) unit, including an LD signal antenna and LD receiver/processor, positioned on the vehicle to receive LD signals from at least three distinguishable LD signal sources and to process these LD signals so that the processed signals can be used to determine the present location of the LD antenna;

providing a cellular phone unit positioned on the vehicle and comprising:

a cellular phone handset that receives audio signals at a first port and converts these audio signals to electronic signals and that receives electronic signals at a second port and converts these electronic signals to audio signals; and

a cellular phone radio transceiver and antenna that receives electronic signals at a signal port and transmits these signals as outgoing radiowave signals at a selected frequency to a central station that is spaced apart from the cellular phone transceiver, that receives incoming radiowave signals from the central station and issues these signals as electronic signals at the signal port, and that can generate and issue an audibly perceptible or visually perceptible incoming call signal that indicates when the radio transceiver and antenna is receiving an incoming radiowave signal intended for that transceiver, where the cellular phone transceiver and antenna are capable of receiving and responding to an LD interrogation signal from the central station that requests information on the present location of the LD antenna; and

providing a central station, spaced apart from and communicating with the LD unit, which issues an LD signal that requests the present location of the LD antenna and that is received by the cellular phone unit and which receives a response to this LD signal from the cellular phone unit;

providing a controller, positioned on the vehicle, connected to and selectively controlling and acting as an interface between the LD unit and the cellular phone unit, for passing signals between the LD unit and the cellular phone unit, wherein (i) when the cellular phone unit receives an incoming phone call, the controller causes the cellular phone unit to delay issuance of an incoming call signal for a selected initial time interval of length .DELTA.t.sub.d ; (ii) when the cellular phone unit receives an LD interrogation signal during an initial time interval of length .DELTA.t.sub.d as part of the incoming phone call, the controller causes the cellular phone unit not to issue an incoming call signal indicating receipt of an incoming call, causes the LD unit to provide the cellular phone unit with information on the present location of the LD antenna, and causes the cellular phone radio transceiver and antenna to transmit this present location information to the central station; and (iii) when the cellular phone unit does not receive an LD interrogation signal during an initial time interval of length .DELTA.t.sub.d as part of the incoming phone call, the controller causes the cellular phone unit to operate as a normal cellular phone and to issue an incoming call signal that is perceptible by an occupant of the vehicle.

17. The method of claim 16, further comprising the step of, when said incoming phone call does not receive an LD interrogation signal during an initial time interval of length .DELTA.t.sub.d as part of the incoming phone call, causing said cellular phone unit to issue an incoming call signal for said vehicle occupant, indicating receipt of an incoming call by said cellular phone unit, until said cellular phone unit goes off-hook or the calling party disconnects or the incoming call signal is issued a selected number of times.

18. The method of claim 16, further comprising the step of concealing at least one of said LD unit and said controller from view on said vehicle.

19. The method of claim 16, further comprising the step of, when a vehicle occupant within the vehicle uses said cellular phone unit to communicate with an other person or facility at another location, causing said cellular phone unit to operate as a normal cellular phone and to allow the vehicle occupant to communicate with the other person or facility, if said cellular phone unit is not responding to said LD interrogation signal at the time the vehicle occupant uses said cellular phone unit.

20. The method of claim 19, further comprising the steps of:

providing a recording switch having an active state and an inactive state; and

providing recording means, connected to said cellular phone unit and to the recording switch, for recording and storing at least one of (i) a contact phone number for an incoming call or outgoing call using said cellular phone unit and (ii) a voice communication, which uses said cellular phone unit, between said vehicle occupant and said other person or facility, when the recording switch is in its active state.

21. The method of claim 20, further comprising the step of causing said cellular phone unit to transmit a recording advisory signal to said central station, indicating that said cellular phone unit has been used for an incoming call or outgoing call, if at least one voice communication or phone number has been recorded by said recording means.

22. The method of claim 21, further comprising the steps of:

providing said cellular phone unit with the capability of receiving from said central station a recording interrogation signal, in response to receipt by said central station of said recording advisory signal; and

providing stored message transmission means, connected to said recording means and to said cellular phone unit, for obtaining information on at least one of (i) said contact phone number and (ii) said voice communication, stored in said recording means, and for transmitting this information to said central station when said cellular phone unit receives a recording response command signal from said central station.

23. The method of claim 16, further comprising the steps of:

providing a message storage memory, connected to said controller; and

when a vehicle occupant uses said cellular phone unit to communicate with an other person or facility at another location while said apparatus is receiving or is responding to said LD interrogation signal, causing said cellular phone unit to abort its response to said LD interrogation signal, to store said LD antenna present location information in the message storage memory, to operate as a normal cellular phone, and to allow the vehicle occupant to contact the called person or facility, if said cellular phone unit is responding to said location interrogation signal at the time the vehicle occupant uses said cellular phone unit.

24. The method of claim 23, further comprising the step of providing stored message transmission means, for retrieving said LD antenna present location information from said message storage memory and for causing said cellular phone transceiver and antenna to transmit said LD antenna present location information to said central station, after said cellular phone handset has returned to an on-hook condition.

25. The method of claim 23, further comprising the step of transmitting an abort signal to said central station, if said cellular phone unit's response to said LD interrogation signal is aborted before this response is completed.

26. The method of claim 16, further comprising the step of:

when an occupant of said vehicle uses said cellular phone unit to communicate with an other person or facility at another location while said apparatus is receiving or is responding to said LD interrogation signal, causing said cellular phone unit to abort its response to said LD interrogation signal, to operate as a normal cellular phone and to allow the vehicle occupant to communicate with the other person or facility, if said cellular phone unit is responding to said location interrogation signal at the time the vehicle occupant uses said cellular phone unit.

27. The apparatus of claim 1, further comprising the step of:

when an occupant of the vehicle uses said cellular phone unit to communicate with an other person or facility at another location while said apparatus is receiving or is responding to said LD interrogation signal, causing said cellular phone unit to complete the transmission of its response to said LD interrogation signal, to then operate as a normal cellular phone and to allow the vehicle occupant to communicate with the other person or facility, if said cellular phone unit is responding to said location interrogation signal at the time the vehicle occupant uses said cellular phone unit.

28. The method of claim 16, further comprising the step of:

when an occupant of the vehicle uses said cellular phone unit to communicate with an other person or facility at another location while said apparatus is receiving or is responding to said LD interrogation signal, causing said cellular phone unit to behave as if it is disabled so that the vehicle occupant will be unable to complete a phone call connection using said cellular phone unit, if said cellular phone unit is responding to said location interrogation signal at the time the vehicle occupant uses said cellular phone unit.

29. The method of claim 16, further comprising the step of selecting said time interval length .DELTA.t.sub.d in the range of about 0.2-30 sec.

30. The method of claim 16, further comprising the step of selecting said time interval length .DELTA.t.sub.d in the range of about 1-5 sec.

BACKGROUND OF THE INVENTION

As used herein, the term "vehicle" refers to land vehicles, to marine vehicles or vessels, and to aircraft. In the United States, about 1.7 million automotive vehicles and about 100,000 marine and aircraft vehicles are reported missing (or stolen) each year. The probability that a land or marine vehicle will be recovered drops dramatically after the vehicle or vessel has been missing for 24 hours or more. Thus, time is of the essence in locating and retrieving a missing vehicle.

Sheffer, in U.S. Pat. No. 4,891,650, discloses a vehicle location system that disperses an array of cellular monitoring stations, each of which detects a cellular alarm signal that is transmitted from a vehicle when the vehicle is determined to be missing. Vehicle location is determined at a base station by the relative alarm strength measured at each detector.

U.S. Pat. No. 5,043,736, issued to Damell et al, discloses a portable vehicle locating system that uses a Global Positioning System (GPS) to determine vehicle location, a cellular phone to report this location to a base station, and an interface to convert GPS signals to cellular phone signals for transmission.

A position-aided subscriber unit for a satellite-based cellular phone system is disclosed by Durboraw in U.S. Pat. No. 5,119,341. A GPS unit determines the location of a transceiver on the ground and transmits This location information to a satellite, to increase the efficiency of satellite-to-receiver communication. This apparatus has use in asset management and in search-and-rescue operations.

Wortham, in U.S. Pat. Nos. 5,155,689 and 5,398,190, discloses installation of a mobile cellular phone unit, with its own identification number, an unspecified location determination unit, and an interface between these two units within a vehicle, to determine and transmit vehicle location. This vehicle location information is displayed on a screen in the vehicle and is periodically transmitted to a base station that is located elsewhere.

An airplane theft detection system that includes a dedicated transponder is disclosed by Robinson et al in U.S. Pat. No. 5,159,344. When the aircraft carrying this transponder is stolen, turning on the aircraft engine activates this transponder and deactivates the normal transponder carried by the aircraft. The dedicated transponder then broadcasts a signal to all nearby air controllers that this aircraft has been stolen. This dedicated transponder has its own current leads to a battery and cannot be de-activated by turning off the normal aircraft operations system. A separate, concealed switch allows the dedicated transponder to be deactivated and allows a normal transponder to be activated. This patent discloses no system for determining the present location of the aircraft or for communicating this present location information to a central station.

In U.S. Pat. No. 5,187,805, Bertiger et al disclose a telemetry, tracking and control (TT&C) system for satellite-aided cellular communications. Here, the cells for the cellular phone system move with the satellite used for the link. GPS-determined location of a mobile user station is used to facilitate handoff from one satellite to another as a satellite cell pattern sweeps across a region containing one or several users.

Song discloses a vehicle locating and navigating system in U.S. Pat. No. 5,208,756. A small receiver, hidden on the vehicle, is activated by a plurality of DTMF signals transmitted from telephone stations with fixed, known locations. The vehicle receiver determines the present location of the vehicle, using relative or absolute signal strengths of the received signals and triangulation of these signals. The vehicle location information is then transmitted to a base station, using a voice synthesis and/or digital signals.

A vehicle tracking system that uses an array of spaced apart cellular phone receivers is disclosed in U.S. Pat. No. 5,218,367, issued to Sheffer et al. One or more sensors, such as vehicle break-in sensors, is positioned on a vehicle, and a cellular phone transmitter on the vehicle transmits a cellular signal when a corresponding sensor is activated. The vehicle's location is determined at a base station, using relative signal strengths of these signals, as received at several spaced apart receivers.

U.S. Pat. No. 5,223,844, issued to Mansell, discloses a vehicle tracking and security system that provides vehicle location information where vehicle break-in, theft, breakdown or other unusual events or emergencies occur. Several "mobile units," each including some type of event sensor, are hidden on the vehicle. When a sensor senses occurrence of an alarm condition or event, a mobile unit causes an on-board transmitter to transmit an event alarm or signal to a control center, together with the location of the vehicle as determined by an on-board GPS receiver. The control center then takes appropriate action, depending on the condition or event and the location of the vehicle.

Dennison discloses a cellular phone system that uses GPS-determined location of a vehicle in which the phone unit is carried to make call management decisions, such as call handoff, in U.S. Pat. No. 5,235,633. The vehicle location information is transmitted to a call management site that determines when cell handoff will occur for a given mobile cellular phone unit.

A vehicle occupant personal security system using Loran-based or GPS-based location determination is disclosed by Simms et al in U.S. Pat. No. 5,334,974. When an emergency condition sensor installed on the vehicle senses the presence of an alarm condition, an on-board system activates a cellular phone system and determines the vehicle location. The on-board system then transmits an emergency condition identifier, a vehicle identifier and vehicle location information to a central station, requesting an appropriate response.

What is needed is a system including cellular telecommunication means that allows determination and reporting of the present location of a missing vehicle, using clandestine means on the vehicle itself. Preferably, the cellular means (1) will function in a normal manner, if used by a vehicle occupant while the vehicle is missing, and (2) can be used to determine and transmit a report on the present location of the missing vehicle, if commanded to do so by a central station that communicates with the vehicle. Preferably, the system should allow recording of any telecommunications made using the cellular means while the vehicle is missing.

SUMMARY OF THE INVENTION

These needs are met by the invention, which provides a location determination and reporting (LDR) system for clandestinely determining and reporting on the present location of a missing vehicle. The vehicle may be in motion or may be motionless when its location is determined and reported, and the vehicle may be anywhere within reach of a cellular station to which the location is reported.

A vehicle is equipped with an operating cellular telephone, with a location determination (LD) unit, including an LD signal antenna and receiver/processor (preferably hidden on the vehicle), that determines the present location of the LD antenna, and with a cellular telephone/LD unit controller and interface. If (or when) the vehicle is reported missing, stolen or moved without authorization from its last known resting place, a central station uses the cellular telephone facility to interrogate the vehicle to determine the present location of the vehicle, even if the vehicle is presently in motion. The owner, agent or other interested person makes a phone call to the cellular phone unit in the vehicle and transmits a location interrogation message that commands the LD signal receiver/processor to provide information on the present location of the LD antenna for transmission by the vehicle cellular phone unit to a designated central station where the owner, tracking agent or police are waiting. When the vehicle cellular phone is contacted and the clandestine vehicle tracking mode is activated, the phone will not signal receipt of an incoming call for an initial time interval of length .DELTA.t.sub.d (.DELTA.t.sub.d .apprxeq.0.2-30 sec, preferably .DELTA.t.sub.d 1-5 sec), awaiting receipt of an anticipated location interrogation signal from the central station requesting that the cellular phone unit provide present location information for the vehicle. If the cellular phone receives this location interrogation signal within the initial time interval of length .DELTA.t.sub.d, the cellular phone does not "ring" in the usual sense, provides no indication that it is communicating with the designated station, and transmits information on the vehicle's present location to the central station.

However, if the anticipated location interrogation signal is not received within the initial time interval of length .DELTA.t.sub.d, the cellular phone will then "ring" audibly or otherwise signal visually, after a time delay of .DELTA.t.sub.d, and behave as a normal cellular phone for the remainder of that phone call. When the system is in a clandestine tracking mode, the controller and cellular phone in the vehicle answer any incoming phone call with a simulated ringing, to avoid alerting any caller to the unusual nature of this phone system. If the incoming call is not a location interrogation signal, the cellular phone handset produces a standard audible ringing tone, and a vehicle occupant can respond to the incoming phone in a normal manner. If the incoming phone call is not answered, the controller and cellular phone will continue to transmit the sounds of simulated ringing or actual ringing for the benefit of the caller, until the caller disconnects, or until a selected large number of rings, such as 10 or 20, has occurred.

The cellular phone may function normally if a person in the vehicle attempts to use the phone. This activity will temporarily pre-empt use of the cellular phone to respond to a location interrogation signal. Thus, an unauthorized user of the vehicle receives no warning or indication that the innocuous cellular phone in the vehicle is being used, or can be used, to track the present location of the vehicle. If one or more phone calls is received by or made from the vehicle while the vehicle is missing, the cellular phone unit and controller can record the telephone number of the calling or called person and/or the voice communication itself during this period, and can transmit this recorded information upon receipt from the central station of a voice communication interrogation signal. Alternatively, the cellular phone can be disabled and rendered unusable unless affirmative action is taken by the vehicle owner or authorized operator, by toggling a concealed switch or entering a confidential alphanumeric symbol sequence into a microprocessor, using an on-board keypad.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating use of one embodiment of the invention for determining the location of a land vehicle, using a satellite-based LD system, such as the Global Positioning System.

FIG. 2 is a schematic view illustrating use of one embodiment of the invention for determining the location of a land vehicle, using a ground-based LD system, such as an FM subcarrier system or a Loran system.

FIG. 3 is a schematic view illustrating use of another embodiment of the invention for a marine vessel.

FIG. 4 is a schematic view of an embodiment of apparatus that may be installed in a vehicle for determining and reporting on the present location of the vehicle.

FIGS. 5A and 5B are a flow chart illustrating a procedure followed by an LDR unit according to an embodiment of the invention.

DESCRIPTION OF BEST MODE OF THE INVENTION

FIG. 1 illustrates use of the invention to monitor and report on the location of a land vehicle 11, using a satellite-based LD system. A cellular telephone unit 13, LD unit 15 and cellular phone/LD unit controller 17 are installed in the vehicle 11. The cellular phone unit 13 is placed in plain sight of, and within the reach of, an operator of the vehicle 11, as a normal cellular phone would be. The cellular phone 13 is connected to a power supply 19 and operates as a normal cellular phone for most purposes. The LD unit 15, preferably hidden from view on the vehicle 11, has an LD signal antenna 23 and associated LD signal receiver/processor 25 that receive LD signals from three or more LD system satellites 27, 29, 31, 33 and determine the present location of the LD antenna, either continuously or periodically or upon demand. The cellular phone unit 13, LD unit 15 and controller 17 (also preferably hidden from view on the vehicle) together form a location determination and reporting (LDR) unit that may be used to practice the invention in one embodiment.

The LD unit 15 is connected to the cellular phone unit 13 through the controller unit 17 that (1) receives cellular phone messages through the cellular phone and (2) delays audible or visual signalling of an incoming call to a vehicle occupant by the cellular phone for a period of time .DELTA.t.sub.d, (.DELTA.t.sub.d .apprxeq.0.2-30 sec, preferably .DELTA.t.sub.d .apprxeq.1-5 sec) to determine whether the cellular phone message is a normal message or is a location interrogation signal. However, the controller unit 17 and cellular phone unit 15 produce a simulated tinging for the benefit of the caller (only) on an incoming call, to avoid alerting this caller to the primary purpose of the cellular phone. If the incoming call is not a location interrogation signal, after the time-out interval of length .DELTA.t.sub.d the cellular phone handset receives a standard audible ringing tone, and a vehicle occupant can respond to the incoming phone in a normal manner. If the incoming phone call is not answered (i.e., the cellular phone unit does not go off-hook), the controller and cellular phone will continue to transmit the sounds of simulated ringing or actual ringing for the benefit of the caller, until the caller disconnects.

If the cellular phone message is a normal message, the controller 17 (3A) allows the cellular phone unit 13 to ring and to function normally. If an occupant in the vehicle 11 answers the cellular phone 13 as a result of receipt of an incoming call signal, the cellular phone would behave normally. If a person in the vehicle 11 uses the cellular phone 13 to place an outgoing phone call, the cellular phone would also behave normally in most circumstances. However, if the signal received on the cellular phone 13 is a location interrogation signal from the central station, the controller 17 will: (3B) suppress any incoming call "ringing" signal within the vehicle 11 by the cellular phone and send a location determination command signal to the LD unit 21; (4B) receive present location information allowing determination of the present location and/or time of observation of the LD antenna 23 from the LD unit; (5B) cause the cellular phone 13 to transmit this present location information to a central station 37 for analysis and (optionally) further signal processing; and (6B) optionally sever the phone connection between the cellular phone 13 and the central station 37 after the present location information is received by the central station. The present location information transmitted by the cellular phone 13 can include the present location coordinates of the vehicle 11, or the unprocessed signals received by the LD unit 15 at the time the controller 17 issues the location determination command, or present locati