Abstract:
A Method and System for Collecting and Surveying Radio Communications From a Specific Protected Area of Operations in or Around a Compound. It is an object of the present invention to provide just such a method to automatically detect communications signals in near real time, from any selectable sub-area of a compound. Such a system would greatly enhance the operational capabilities of the twenty-first century organization by providing a real-time capability to secure radio communications in and around a compound. The system has all the abilities of the system described in the &#39;976 application, but is further able to automatically detect the direction of the incoming signals (relative to two or more collector subsystems in communication with each other), and thereafter to add that information to the surveillance decision logic such that the actual geographical location, as adjusted by the calibration information for the particular compound surveillance decision logic. Secondly, the system has the capability of being calibrated such that the particular RF environment of the compound in question is uniquely mapped. The calibration tables maintained by each network-attached directional collection node of the system invention in order to provide a more robust and accurate signal geo-location system. Thirdly, the system is able to automatically pinpoint the geographic area of the source of the incoming signals and add that information to the monitoring decision logic. Finally, the system provides a user interface to operators so they can easily select areas to monitor, and easily calibrate the system for maximum precision.

Description:
This application is a continuation-in-part of application Ser. No. 10/829,858, filed Apr. 21, 2004 now abandoned, and Ser. No. 11/201,164, filed Aug. 11, 2005, and Ser. No. 11/201,144, filed Aug. 11, 2005 now abandoned. 
     This application is filed within one year of, and claims priority to Provisional Application Ser. No. 60/637,402, filed Dec. 17, 2004. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to electronic information surveillance and security systems and, more specifically, to a Method and System for Collecting and Surveying Radio Communications From a Specific Protected Area of Operations in or Around a Compound. 
     2. Description of Related Art 
     The twenty-first century has seen a radical increase in the importance of both physical and communications security. Many facilities and operations areas: military bases, intelligence buildings, financial buildings, airports, etc. need greater radio communications security than ever before. 
     An example of the need for greater radio communications security is the operations area in and around airports. Today someone with a transmitter near the end of an airport runway can cause material damage and loss of life by attempting to disrupt communications between airport towers, TRACONs and the airplanes themselves. 
     Even traditionally sensitive areas such as military bases and intelligence buildings need the ability to detect and monitor radio communications in various areas inside them. For example, various areas, like prisons, are mandated by their security policy to be off-limits for cell phone use. Isolating and monitoring cell phone transmissions in those areas would automatically enforce the policy. 
     What is needed therefore in order to enhance radio communications security for sensitive areas of operation is an invention that has 1) The ability to quickly localize and monitor all radio communications, and 2) the ability to be calibrated to instantly determine the location of transmission sources for specific frequencies. Both must be applied to make such a system accurate. The user of this invention can use the system to isolate and monitor transmissions simply by specifying the geographic area of the transmission source to be monitored. 
     The term “calibration” is used in the Electronic Warfare environment to profile a land or air vehicle-based electronic detection system. The approach used to calibrate such a vehicle is to circle the vehicle with an electronic transmitter. The transmitter is periodically, at known locations, caused to transmit (potentially at different frequency bands of interest). The transmission detection equipment mounted inside of the vehicle is used to detect and record these transmissions. In this manner, blind spots, areas having anomalous reflective characteristics, and any other non-standard signal behavior will be detected and incorporated into the profile of the sensing equipment. Once calibrated, the vehicle&#39;s equipment performance is known and should not change unless there are equipment or structural changes made to the vehicle. 
     This type of calibration has never been done to create a profile for the electronic transmission characteristics of a physical compound or installation. An electronic transmission surveillance system monitoring a physical compound or installation would be much more accurate if the effects of the buildings, equipment, and other such things were known and taken into account by the transmission localizing system. It is this information that is the subject of the present invention. 
     SUMMARY OF THE INVENTION 
     In light of the aforementioned problems associated with the prior devices and methods used by today&#39;s military organizations, it is an object of the present invention to provide a Method and System for Collecting and Surveying Radio Communications From a Specific Protected Area of Operations in or Around a Compound. 
     Sensitive operations areas need accurate, efficient, and effective tools to monitor any suspicious transmissions from specified sub-areas. These specific areas to be monitored can be as small as an individual room in a building. A fundamental change in RF detection and monitoring efficiency is needed for the modem organization to achieve and maintain this level of precision for electronic security in its area of operations. 
     It is an object of the present invention to provide just such a method to automatically detect communications signals in near real time, from any selectable sub-area of a compound. Such a system would greatly enhance the operational capabilities of the twenty-first century organization by providing a real-time capability to secure radio communications in and around a compound. The system should have real time direction-finding methods, such as those espoused by the invention of application Ser. No. 11/201,164. The system has all the abilities of the system described in the &#39;164 application, but is further able to automatically detect the direction of the incoming signals (relative to two or more collector subsystems in communication with each other as those espoused by the invention of application Ser. No. 11/201,144), and thereafter to add that information to the surveillance decision logic such that the actual geographical location, as adjusted by the calibration information for the particular compound surveillance decision logic. 
     The preferred system should first have all the abilities of the inventions described by the &#39;164, and &#39;144 patent application. Secondly, the preferred system should have the capability of being calibrated such that the particular RF environment of the compound in question is uniquely surveyed. The calibration tables must be maintained by each network-attached directional collection node of the system invention thereby creating a far more accurate signal geolocation system. Thirdly, the preferred system should be able to automatically pinpoint the geographic area of the source of the incoming signals, to add that information to the monitoring decision logic. Finally, the preferred system should provide a user interface to operators so they can easily select areas to monitor, and easily calibrate the system for maximum precision. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, of which: 
         FIG. 1  is a diagram of an area of operations/compound; 
         FIG. 2  is another diagram of a protected compound, in this case an airport; 
         FIG. 3  is a flowchart depicting the operational method of the calibrated system of the present invention; 
         FIG. 4  is a drawing of a directional collection node of the present invention; and 
         FIG. 5  is a flowchart depicting the preferred method for calibrating the system of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide a Method and System for Collecting and Surveying Radio Communications From a Specific Protected Area of Operations in or Around a Compound. 
     The parent applications to this patent application, namely, Ser. No. 10/829,858, filed Apr. 21, 2004 for “Method and Apparatus for the Intelligent and Automatic Gathering of Sudden Short Duration Communications Signals” and two of its continuation-in-part applications, namely, Ser. No. 11/201,164 filed Aug. 11, 2004 for “Improved Method and Signal Intelligence Collection System That Reduces Output Data Overflow in Real-Time”, and Ser. No. 11/201,144 filed Aug. 11, 2004 for “Method and Technique For Gathering Signal Intelligence of All Radio Communications Only Originating From Specific Selected Areas” describe other application environments for the detection apparatus, system and method utilized by the present invention to monitor and localize the electronic emissions in a particular installation or compound. While the inventions disclosed in these three parent patent applications are not associated with the surveillance of a compound (such as is the case with the instant invention/disclosure), the detection systems are essentially the same, and therefore the disclosures contained within those three parent applications are incorporated herein by reference, and will be referred to as the “parent applications” later in this document. 
     The present invention can best be understood by initial consideration of  FIG. 1 .  FIG. 1  is a diagram of an area of operations/compound. It shows the location of three network connected directional collection systems within the compound, along with the location of an area that the user&#39;s security policy says to monitor. The directional collection systems are numbered  1 ,  2 , and N, each with directional signal collection capability as described below. Area A is the area of interest (i.e. the compound), areas B and C are the areas to be monitored. Areas a, b, c, and d are actual buildings in the compound (or military base). R is the road between the buildings. 
     The depicted scenario includes three network-attached directional receiving systems, along with outlined areas of interest. In this scenario, the system user could choose to monitor any of the three “sub-areas” A, B, and C. Sometimes the user would want to monitor the entire compound (area A) at a certain frequency, but the typical situation involves monitoring only specific sub-areas. So if only sub-areas B and C of the compound are to be monitored, then the system operator enters the geographic coordinates of those areas for the system to monitor. The system then monitors and records primarily signals transmitted from areas B and C. Any transmissions from areas outside of B and C may be ignored by the system. 
       FIG. 2  is another diagram of a protected compound, in this case an airport. The sketch is much like  FIG. 1 , with the network connected directional collection systems (specifically  10 A,  10 B and  10 C—identical versions of the system  10  described elsewhere in this disclosure) distributed around the airport&#39;s property. Interfering RF transmissions coming from areas near the runways or around the outlying neighborhood can be detected and located in real time. In addition, the signals are demodulated and stored for evidence purposes of criminal court trials, should an individual purposely interfere with airport operations. 
       FIG. 3  is a flowchart depicting the operational method of the compound-monitoring system of the present invention. The first and most important step in the flow of operations is to calibrate the system  100  for the most precise detection of the location of signal sources. This calibration  100  is done via a careful survey of the compound area to be monitored. The survey is performed repeatedly—once at the time of system installation, and then every so often to test the ongoing effectiveness of the system. The survey allows the system to adjust the geolocation calculations for the behavior of multipath reflections and signal absorptions of the radio communications signals. Thus the surveys calibrate the system to match the exact compound environment. 
     Each system installed in each compound must be calibrated in the same manner to become familiar with the compound&#39;s unique and specific radio environment. Calibration of the system for each and every compound is of importance to maintain a high degree of accuracy for each compound. The system is therefore customized to detect and recognize signals for each sensitive area of each compound. Of course, if either the security needs or the radio environment changes sufficiently, the system can be re-calibrated. For example, if extra buildings are put in the compound the system should be re-calibrated to account for the changed multipath environment. 
     The survey is outlined by  FIG. 5 , and produces a location calibration table for each respective directional wideband collection node  10 . First, each node  10  stores its exact location, for input to the geolocation calculations. Each node also stores a map of the compound, for the operator to reference through a user interface at the node. 
     The operator of the system then initializes the system with all the location data of the operations area, the areas to be monitored. For simplicity and ease of use, the operator uses a GUI-based map to indicate these parameters to the system. A few mouse clicks are sufficient to easily set up the system to operate effectively. 
     The operator then activates the system  102 . The system starts monitoring the various areas specified. The individual directional monitoring systems behave as described in the aforementioned parent applications to this disclosure. 
     Once any transmission in the frequency band of interest is detected, the location is determined  104 . Then the location is corrected with the calibration table  106 . Correcting the location means to access the empirical data within the calibration table, and comparing the apparent location of the detected signal to that empirical data. Through interpolation and/or extrapolation, the error found in the calibration data can be applied to the data of the apparent signal in order to determine a best estimate of the transmitter&#39;s actual location. 
     The corrected/calculated location is then compared to the sub-areas of the compound that were preset to be monitored  108 . If the system determines that the signal meets preset criteria, the system then implements the security policy by sending an alarm to the GUI controls, starting to record the transmission, and so forth  110 . The GUI can be set up to effect both audio and visual alarms; the security staff can then be scrambled to deal with the source of the signal. 
     The system of this invention can be very precisely tuned over time to minimize, automatically, the number of false alarms raised by the system. Thus the accuracy and effectiveness of the system avoids waste of resources, especially the human resources of the security staff. 
     If we now turn to  FIG. 4 , we can more closely examine the equipment that is actually doing the signal detection, analysis and geolocation. 
       FIG. 4  is a drawing of a directional collection node of the present invention  10  (the generic device referred to as  10 A,  10 B and  10 C in  FIG. 2 ). A network of collection nodes  10 , plus specialized calibration tables and software, comprises the system of the present invention. In brief, the collection nodes  10  are identical in hardware, software, and behavior to the wideband collection boxes described in the patent application Ser. No. 11/201,164 filed Aug. 11, 2005, “Improved Method and Signal Intelligence Collection System that Reduces Output Data Overflow in Real-Time.” Multiple instances of the previous invention can be installed throughout a compound, and networked together to provide triangulation data for specific areas of the compound. The operator of the combined system can specify areas within the secured compound that are to be monitored, and the system will automatically monitor or sound alarms on sudden occurring signals whose sources lie in those respective areas. 
     DIAGRAM 4 REFERENCE NUMERALS 
       10  Network-Attached Directional Wideband Signal Collection System Node 
       12 ,  13 ,  14  Receiving DF Antennas 
       16  GPS Antenna 
       18  GPS Receiver 
       20 ,  21 ,  22  Wideband Downconverters and Filters 
       24  Phase/Frequency Reference 
       26 ,  27 ,  28  Analog-to-Digital Converters (AID) 
       30  FIFO Buffer 
       32 ,  33 ,  34  Fast Fourier Transformations (FFT&#39;s) 
       36  Direct Digital Downconvertors 
       38  Hardware Logic DSP 
       40  DF Algorithm 
       42  Hardware Logic DSP 
       44  Digital Filter 
       46  New Signal Detection Logic 
       48  Database of Spectrum Masks 
       50  Controlling CPU with Geolocation Algorithms 
       52  User Commands 
       54 A SIGINT data to network (Time-Tagged FFT/DF Frame data to other Wideband Boxes) 
       54 B SIGINT data from network (Time-Tagged FFT/DF Frame data from other Wideband Boxes) 
       56  Demodulated Signals 
       58  Real-time Spectrum Displays 
     Now turning to  FIG. 5 , we can examine the “calibration” method that provides so much value through the system described above.  FIG. 5  is a flowchart depicting the preferred method for calibrating the system  100  of the present invention. 
     Most important and unique to this invention is the method described herein for security personnel to survey the radio characteristics of a specific compound. The security personnel can walk around a specific compound, into its most sensitive areas, and key up various transmitters, on various frequencies, from each area. The wideband collection nodes of the networked system then detect and record the transmission from each transmitter, from each sensitive area, for later recognition of a recurrence of the use of that frequency from the specific sensitive area. Thus the entire system is finely calibrated to look for and recognize specific transmission frequencies from specific sensitive areas of the compound or from within a specific offices in a building. Multipath reflections and obstructions are calibrated into the system. This is a very unique approach as compared to the conventional electronic warfare/detection system. In the typical system, such as those described by the parents to this application, unknown and unlocated transmitters are sought to be identified (as friend, foe or unknown) by a located transmission. Here, the use of the calibration tables changes that process to one of comparing unknown transmission to known locations (possibly with some extrapolation or interpolation depending upon the granularity of the calibration data) to adjust the apparent location to a known location by applying a calculated correction to the apparent geolocation. 
     System calibration must be performed for every compound in which the system is installed. The calibration corrects the discrepancies between the calculated and the actual (or apparent) location of the source of a signal. Each compound is physically different, and will reflect and block the frequency transmissions in various ways. These reflections will cause errors to accumulate in the geolocation calculations in each wideband collection node (i.e. each node will very likely experience its own unique error for each discrete transmission location within the compound). The differences between the calculated and the actual locations are therefore stored, indexed by location and frequency, in the calibration table of each respective wideband node. 
     The method of  FIG. 5  assumes that enough collection nodes receive each signal, so that a triangulation can be calculated. If the calibration step reveals any areas from which a signal cannot be received by enough collection nodes for triangulation (“blind spot”), additional nodes must be added to the network to cover those areas. 
     All of the processing that occurs in the invention runs in near real-time, fast enough to react to even fast frequency-hopping transmitters or cell phones. This invention is unique since no other system has the capability or performance to perform these operations this quickly and accurately. 
     Once the collection systems  10  are placed in and/or around the compound  200 , each node  10  has a map of the compound entered into it  202 . On each of these internal maps, the exact map coordinates of each node is also entered  204 . 
     Then, or at any time prior to the next step, security personnel determine the frequencies of interest for each sensitive location. These frequencies could be cell phone frequency bands, wireless network frequency bands, and so forth. The variable N in  FIG. 5  stands for the number of frequencies of interest, for each sensitive location. 
     The security personnel also must determine the number of locations to calibrate the nodes for. If a particular sensitive area in the compound is large, a number of location readings may need to be done in the area. The personnel must determine how fine a location resolution is needed to provide adequate coverage and security. The variable M in  FIG. 5  stands for the total number of locations to take readings 
     The security personnel then walk the compound, to each of the M locations  206 . The personnel bring a transmitter with them that can transmit each of the N frequencies of interest for each location. At each location M, the actual geolocation of location M is recorded  208 . The calibrating personnel then key up the transmitter while the monitoring system is collecting data  210 . Each of the N frequencies is transmitted in turn  218 ,  224 ,  210 , allowing the collection nodes to triangulate on its signal  212 . Both the calculated locations and the exact locations for each frequency N are then stored in the calibration table in each node  214 . The process is repeated for each of the M locations  220 ,  226 ,  206 . 
     The calibration table allows each node to locate, very precisely, the transmission source of a frequency of interest transmitted from a sensitive area. The precision of the system is limited by the resolution of the survey (referred to as the “granularity” of the calibration table); the survey must be as complete as possible, so the calibration step is important. The calibration is also ongoing, as more and more frequencies and locations are added to each node&#39;s lookup table. The nodes can then alert security personnel of the location of the transmission of any frequency of interest, with very few false alarms. The system automatically knows the area the transmitter is being used, down to the specific room in a building. Information this accurate and this automated is very powerful in the enforcement of electronic security in sensitive areas and is only possible through this calibration step and method. 
     The ongoing survey is the repeated testing of the system&#39;s monitoring effectiveness. Again, a transmitter is carried around the area of operations, and is keyed up in each area to be monitored. The system is then checked to ensure that the new signal is detected as unusual, and localized very precisely. This survey and calibration should occur at the time intervals specified by the security policy. This ongoing survey also detects whether the radio environment has changed enough over time to cause parts of the system to be re-calibrated. 
     This approach yields an enhanced electronic information security capability for radio communications in and around specific areas of operations, especially areas of significance to national security (such as military bases, intelligence buildings, government buildings, airports, special events, etc.). This state-of-the-art invention allows users to isolate and monitor the radio communications in these specific sensitive areas (compounds) of operations. These areas can be large or small, from large airport facilities down to specific areas within buildings (to the exact office). Operators of the invention can survey an individual compound&#39;s radio characteristics and calibrate the system precisely for the characteristics of each individual compound. Thus this invention greatly enhances the electronic information security capabilities of sensitive areas of operation, both civilian and military. 
     Thus this invention is unique in its ability to be applied to a wide range of operations areas that require very tight, precise radio communications monitoring and security. It is also unique in that it fine-tunes the monitoring of the system to match the operation area&#39;s physical building or location layout. The system can be precisely calibrated to detect the exact location of the source of specific frequency transmissions from specific sensitive areas in the compound. This invention is therefore vital to the interests of United States national security. 
     Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.