Patent Publication Number: US-9851448-B2

Title: Obtaining pseudorange information using a cellular device

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     The present application is a divisional of U.S. application Ser. No. 13/842,447, filed Mar. 15, 2013, which is incorporated herein by reference in its entirety for all purposes. U.S. application Ser. No. 13/842,447 claims priority to U.S. Patent Application No. 61/746,916 filed on Dec. 28, 2012 entitled “IMPROVED GPS/GNSS ACCURACY FOR A CELL PHONE” by Rudow et al., and assigned to the assignee of the present application. 
    
    
     BACKGROUND 
     The Global Positioning System (GPS) and its extensions in the Global Navigation Satellite Systems (GNSS) have become thoroughly pervasive in all parts of human society, worldwide. GPS and GNSS receivers in the form of chipsets have become widely incorporated into cell phones and other types of cellular devices with cellular-based communications equipment. 
     Typically, cellular devices include highly integrated GPS/GNSS chipsets that are designed to work with the E-911 service primarily, and are not designed to provide anywhere near a full range of features and outputs. They do provide a position fix, but are not designed to make available very many other parameters of interest. All GPS/GNSS receivers must acquire, track and decode a data message that conveys information about the location of the satellites in space, and time information. The principal additional parameter obtained is the “pseudorange.” However, this set of data is not available as an output from the cell phone GPS chipsets for use by the cellular device itself. In circumstances where it is available, it is under access control by the vendor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The accompanying drawings, which are incorporated in and form a part of this application, illustrate embodiments of the subject matter, and together with the description of embodiments, serve to explain the principles of the embodiments of the subject matter. Unless noted, the drawings referred to in this brief description of drawings should be understood as not being drawn to scale. Herein, like items are labeled with like item numbers. 
         FIG. 1  depicts a block diagram of a cellular device for obtaining pseudorange information, according to one embodiment. 
         FIG. 2  depicts a block diagram of a cellular device for obtaining pseudorange information, according to one embodiment. 
         FIG. 3  depicts a flowchart of a method for obtaining pseudorange information using a cellular device, according to one embodiment. 
         FIGS. 4A and 4B  depict a flowchart  400  of a method for processing pseudorange information, according to one embodiment. 
         FIG. 5  is a flowchart  500  of a method for performing a pseudorange fetch operation in accordance with one embodiment. 
         FIG. 6  shows components for implementing secure user plane location in accordance with one embodiment. 
         FIG. 7  is a block diagram showing components of an improved accuracy SUPL client in accordance with one embodiment. 
         FIG. 8  depicts a flowchart  800  of a method for obtaining pseudorange information using a cellular device, according to one embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Reference will now be made in detail to various embodiments of the subject matter, examples of which are illustrated in the accompanying drawings. While various embodiments are discussed herein, it will be understood that they are not intended to limit to these embodiments. On the contrary, the presented embodiments are intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope the various embodiments as defined by the appended claims. Furthermore, in the following Description of Embodiments, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present subject matter. However, embodiments may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the described embodiments. 
     Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the description of embodiments, discussions utilizing terms such as “accessing,” “extracting,” bridging,” determining,” displaying,” “performing,” providing,” “obtaining,” calculating,” “receiving,” “storing,” “notifying,” “matching,” “creating,” “generating,” “communicating,” “transmitting,” “using,” “requesting,” “providing,” “activating, “deactivating,” “initiating,” “terminating,” “causing,” “transforming data,” “modifying data to transform the state of a computer system,” or the like, refer to the actions and processes of a computer system, data storage system, storage system controller, microcontroller, processor, or similar electronic computing device or combination of such electronic computing devices. The computer system or similar electronic computing device manipulates and transforms data represented as physical (electronic) quantities within the computer system&#39;s/device&#39;s registers and memories into other data similarly represented as physical quantities within the computer system&#39;s/device&#39;s memories or registers or other such information storage, transmission, or display devices. 
     OVERVIEW 
     Cellular devices, such as cell phones and non-voice enabled cellular devices, can provide pseudorange information that can be used in surveying. However, the pseudorange information from cellular device chipsets are only available under a limited set of conditions, usually only when performing a E-911 service call, and then only for use by the Assisted GPS service located in conjunction with the E-911 service facility. Therefore, according to one embodiment, a GPS/GNSS chipset, which calculates pseudorange information for use by the GPS/GNSS chipset, embedded within a cellular device is accessed. The pseudorange information from the GPS/GNSS chipset is extracted for use elsewhere in the cellular device outside of the GPS/GNSS chipset. 
     Examples of Systems for Obtaining Pseudorange Information 
       FIG. 1  depicts a block diagram of a cellular device for obtaining pseudorange information, according to one embodiment. Examples of a cellular device  100  include a cell phone, a non-voice enabled cellular device, a Trimble® Juno™, and a Trimble® GeoExplorer®. 
     As depicted in  FIG. 1 , the cellular device  100  includes a GPS/GNSS chipset  170 , a GPS/GNSS receiver  107 , a processor  172  that is part of the GPS/GNSS receiver  107 , a chipset accessor  141 , a pseudorange information extractor  142 , an improved accuracy SUPL client  701 , a pseudorange information bridger  143 , a pseudorange information processing component  150 , an operating system  160 , a location manager  161 , a location displayer  162 , and a processor  109  that is outside of the GPS/GNSS receiver  107 . According to one embodiment, the chipset accessor  141 , the pseudorange information extractor  142 , the pseudorange information processing component  150 , and the pseudorange information bridger  143  are a part of the improved accuracy SUPL client  701 . According to one embodiment, the pseudorange information processing component  150  includes a pseudorange corrector  223 , carrier phase smoothing  226  and an augmented position determiner  224 . 
     According to one embodiment, the processor  172  and the GPS/GNSS receiver  107  are a part of the GPS/GNSS chipset  170 . According to one embodiment, the chipset accessor  141 , pseudorange information extractor  142 , the pseudorange information bridger  143 , the improved accuracy SUPL client  701 , the operating system  160 , and the processor  109  are located in a portion of the cellular device  100  that is outside of the GPS/GNSS chipset  170 . The location manager  161  can be a part of the operating system  160  and external to the GPS/GNSS chipset  170 . According to one embodiment, the location displayer  162  is a part of the location manager  161 . According to one embodiment, the chipset accessor  141 , pseudorange information extractor  142 , the pseudorange processing component, pseudorange corrector  223 , carrier phase smoothing  226 , augmented position determiner  224 , pseudorange information bridger  143 , and improved accuracy SUPL client  701  are application programming interfaces (API) function applications that reside in memory of the cellular device  100  and are executed by a processor  109  of the cellular device  100 . 
     The GPS/GNSS receiver  107  can perform GPS measurements to derive raw measurement data for a position of the cellular device  100 . The raw measurement data can provide an instant location of the cellular device  100 . According to one embodiment, the raw measurement data is the pseudorange information that is extracted (also referred to as “extracted pseudorange information”). The extracted pseudorange information may be referred to as uncorrected pseudorange information, observed pseudorange information, or unsmoothed pseudorange information. Conventionally, the raw measurement data is only for use by the GPS/GNSS chipset  170  and the GPS/GNSS chipset  170  calculates pseudorange information that is only for use by the GPS/GNSS chipset  170 . Examples of pseudorange information are uncorrected pseudorange information, differential GNSS corrections, high precision GNSS satellite orbital data, GNSS satellite broadcast ephermis data, and ionosopheric projections. 
     The chipset accessor  141  is configured for accessing the GPS/GNSS chipset  170 . The pseudorange information extractor  142  is configured to extract the pseudorange information that is accessed. The extracted pseudorange information can be received and stored continuously. The pseudorange information bridger  143  is configured for bridging the pseudorange information from the GPS/GNSS chipset  170  to the location manager  161  that resides in the operating system  160  of the cellular device  100 . 
     According to one embodiment, the chipset accessor  141 , the pseudorange information extractor  142 , the pseudorange information processing component  150  and pseudorange information bridger  143  are a part of an improved accuracy SUPL client  701 . For example, The SUPL client  701  can interface between the GPS/GNSS chipset  170  and the location manager  161 , which resides in the operating system  160 . The pseudorange information can be obtained from the processor  172  of the GPS/GNSS receiver  107  using a command via a high precision Secure User Platform Location (SUPL). 
     According to one embodiment, the GPS/GNSS chipset  170  is accessed using an operation that is a session started with a message that is an improved accuracy Secure User Platform Location (SUPL) start message or a high precision SUPL INIT message. According to one embodiment, the message is a custom command that is specific to the GPS/GNSS chipset  170  (also referred to as “a GPS/GNSS chipset custom command”) and the improved accuracy SUPL client  701  can have access to the raw measurements of the GPS/GNSS chipset  170 . 
     A worker thread associated with the SUPL client  701  can monitor the raw measurements delivered by the GPS/GNSS chipset  170  into the GPS/GNSS chipset  170 &#39;s memory buffers, cache the raw measurements and use the raw measurements to determine a position fix. The pseudorange information extractor  142  and the pseudorange information processing component  150  can be associated with the worker thread. For example, the pseudorange information extractor  142  can cache the raw measurements and the pseudorange information processing component  150  can determine the location. 
     According to one embodiment, the cellular device  100  can improve the accuracy of the extracted pseudorange information. For example, the extracted pseudorange information can be improved by applying pseudorange corrections to the extracted pseudorange information. Examples of an improvement source that provides pseudorange corrections are corrections feeds  640  ( FIG. 6 ), correction service  121 , FM radio distribution  126 , or satellite radio distributor  127  ( FIG. 2 ), or a combination thereof, as will become more evident. According to one embodiment, an improvement source is located outside of the cellular device  100 . A pseudorange corrector  223  can be notified that the pseudorange information is being stored. The pseudorange corrector  223  can improve the accuracy of the pseudorange information by applying pseudorange corrections to the extracted pseudorange information. More specifically, the pseudorange corrections can be received, for example, directly from an improvement source that is located outside of the cellular device  100 . A pseudorange correction fetch can be notified to determine if pseudorange corrections are in memory already. If the pseudorange corrections are not already in memory, the pseudorange correction fetch can be notified that pseudorange corrections need to be fetched from an improvement source. The pseudorange corrector  223  can create corrected pseudoranges by applying pseudorange corrections to the extracted pseudorange information. The corrected pseudoranges can be received by the augmented position determiner  224 , which can perform a least squared function on the corrected pseudoranges. 
     In another example, the extracted pseudorange information can be improved by applying carrier phase information to the extracted pseudorange information. More specifically, the extracted pseudorange information can be improved by applying carrier phase information, such as carrier phase and pseudorange signals that is obtained from one or more satellites that are in view of the GPS/GNSS receiver  107 , to the extracted pseudorange information. A carrier phase smoothing  226  can create smoothed pseudorange information by applying the carrier phase information to the extracted pseudorange information. The smoothed pseudorange information can be received by the augmented position determiner  224 , which can perform a least squared function on the smoothed pseudoranges. 
     In yet another example, the extracted pseudorange information can be improved by applying additional information that is obtained, for example, from one or more of a compass, gyroscope, accelerometer, and a source accessed via a Wifi or via a short range wireless communication protocol operating in the range of frequencies between 2402-2480 MHz, such as Bluetooth Low Energy (BLE)®. The additional information applicator  151  can obtain and create corrected data by apply the additional information to the extracted pseudorange information. The corrected data can be received by the augmented position determiner  224 , which performs a least squared function on the corrected data. 
     Applying pseudorange corrections, carrier wave information, or additional information to extracted pseudorange information are examples of improving the accuracy of the pseudorange information. In still another example, the extracted pseudorange information is received by the augmented position determiner  224 , which performs a least squared function on the extracted pseudorange information without further improvements to the extracted pseudorange information. 
     The output of the augmented position determiner  224  can be used for determining the location of the cellular device  100 . For example, a latitude, longitude and altitude can be determined based on the output of the augmented position determiner  224 , which can be displayed by the location displayer  162 . When the location has been determined based on an improvement that results from applying pseudorange corrections, carrier wave information, or additional information to the extracted pseudorange information, the location, according to one embodiment, is a position fix of the cellular device  100 . 
     According to one embodiment, a requested mode can be used as a part of determining whether or not to apply any improvements, such as pseudorange corrections, carrier wave information or additional information, to the extracted pseudorange information. For example, if the requested mode requests a location without improvements, the location can be determined without improvements even if improvements are available or can be obtained. If the requested mode requests a position fix, then the location can be determined with improvements if improvements are available. 
     The characteristics of the GPS/GNSS chipset  170  can be used to determine whether to apply pseudorange corrections, carrier phase information, or additional information. For example, the characteristics of the GPS/GNSS chipset  170  can be used to determine whether the pseudorange corrections or carrier phase information provided by the chipset  170  provides higher accuracy. For example, the pseudorange corrections from some GPS/GNSS chipsets provide higher accuracy than the carrier wave information from those GPS/GNSS chipsets. However, the carrier wave information for other GPS/GNSS chipsets may provide higher accuracy than the pseudorange corrections from the other GPS/GNSS chipsets. 
     According to one embodiment, a quality of position (QOP) position metric is used to determine whether to improve pseudorange information by applying pseudorange corrections. For example, a QOP position metric can be determined from data obtained from the GPS/GNSS receiver  107 . If the QOP position metric is less than a pre-determined QOP, pseudorange corrections are requested from an improvement source. Examples of requested pseudorange corrections are satellite orbital data, high precision ephemeris data, and DGPS/DGNSS corrections. 
     According to one embodiment, the extracted pseudorange information is observed and uncorrected. Time tags can be used for matching calculated pseudorange correction information obtained from reference stations with observed pseudorange information. 
     According to one embodiment, the pseudorange information bridger  143  communicates the output of the augmented position determiner  224  to the location manager  161  in the operating system  160 . According to one embodiment, the output of the augmented position determiner  224  is a location that is defined in terms of latitude, longitude, and altitude. The location displayer  162  can display the location with respect to a map. 
     Conventionally, the GPS/GNSS chipsets  130  on cellular device  100   s  have been designed to deliver pseudorange information to an emergency service when an E-911 call that is made on the same cellular device  100 . Therefore, according to one embodiment, the emergency service is an example of an originally intended recipient of the pseudorange information. However, according to various embodiments, the pseudorange information is delivered to a recipient that it was not originally intended for (also referred to as “originally unintended recipient”). For example, the pseudorange information can be delivered to a portion of the cellular device  100  outside of the GPS/GNSS chipset  170 . More specifically, a GPS/GNSS chip custom command can be used to access and extract the pseudorange information as discussed herein. In another example, an E-911 operation can be initiated on the cellular device  100 , the pseudorange information can be accessed and redirected to a portion of the cellular device  100  outside of the GPS/GNSS chipset  170  and the E-911 operation can be terminated prior to the emergency service being notified and prior to the pseudorange information being transmitted from the GPS/GNSS chipset  170  to the emergency service. According to one embodiment, the pseudorange information is accessed at the originally unintended recipient using the extracted pseudorange information. 
       FIG. 2  depicts a block diagram of a cellular device, according to one embodiment. For example,  FIG. 2  depicts a cellular device  105  that includes satellite radio receiver  106 , GPS/GNSS receiver  107 , FM radio receiver  108 , processor  109 , memory  110 , which in turn includes improved accuracy SUPL client  701 , cellular transceiver  111 , display  112 , audio  113 , Wi-Fi transceiver  114 , IMU  115 , pseudorange fetch  221 , pseudorange correction fetch  222 , pseudorange corrector  223 , carrier phase fetch  225 , carrier phase smoothing  226 , augmented position determiner  224 , and bus  116 . 
     The cellular device  105  is directly or indirectly in communication with communication satellites  101 , global navigation satellites  102 , terrestrial radio broadcast  103 , GPS/GNSS reference stations  120 , correction services  121 , distribution service  125 , FM radio distributor  126 , satellite radio distributor  127  over various communications links, such as, communications link  130 , cellular network  122 , Internet  123 , and local Wi-Fi  124 . 
     A global navigation satellite system (GNSS) provides a GNSS receiver with the capability to determine its location based on positioning signals transmitted from the GNSS satellites (of the GNSS satellite system) in terms of longitude, latitude, and altitude to within a few meters or even centimeters. GNSS based positioning has a wide range of applications including navigation and tracking and automatic positioning. 
     Generally, for determining its position, a GNSS receiver first determines distances to a plurality of GNSS satellites. Each individual distance measurement made by the receiver to a satellite located in a known orbit position traces the GNSS receiver on the surface of a spherical shell at the measured distance from the satellite. By taking several such measurements and determining an intersecting point of the spherical shells, a position fix can be generated. The distance measurements to the satellites are based on a time of flight measurement of positioning signals transmitted by the satellites to the receiver and thus the measurements depend on an exact timing. Normally, three distance measurements to three known satellite positions are sufficient to resolve a receiver position in space, however, with the receiver clock offset from satellite clock time being the fourth unknown in the equations, measurements on four satellites are needed to determine the position of the receiver. 
     The orbit position of the satellite may be determined based on a data message superimposed on a code that serves as a timing reference. The GNSS receiver can compare the time of broadcast at the satellite encoded in the transmission with the time of reception measured by an internal clock at the receiver, thereby measuring the time of flight to the satellite. GNSS systems provide satellite data messages that transmit a code with a timing reference, enabling a GPS/GNSS receiver to compare a successively delayed internal replica of this code with the received code from the satellite. By progressively delaying the local copy, the two signals become aligned in time. That delay is the time needed for the signal to reach the GPS/GNSS receiver, and from this the distance from the satellite can be calculated. 
     The Real-Time Kinematic (RTK) method was developed to provide greatly improved accuracy in position determination, with a level of precision suitable for use in surveying. RTK positioning performs measurements of the carrier phase of the satellite signals and makes estimates of the exact number of carrier frequency wavelengths (19.6 cm) to each satellite. The method is well-known in the GPS/GNSS positioning arts. To improve the accuracy of the estimation, the RTK method provides reference data on the same set of satellite observables from another source. These reference station observables are often relayed to the rover via ground based radio transmission, in order to enable the receiver to perform the double-differencing process that removes error contributions. 
       FIG. 2  depicts a plurality of broadcast sources that are used to convey data and media to a cellular device  105 , according to one embodiment. As an example, the cellular device  105  can receive broadcast signals from communication satellites  101  (e.g., two-way radio, satellite-based cellular such as the Inmarsat or Iridium communication networks, etc.), global navigation satellites  102 , which provide radio navigation signals (e.g., the GPS, GNSS, GLONASS, GALILEO, BeiDou, Compass, etc.), and terrestrial radio broadcast (e.g., FM radio, AM radio, shortwave radio, etc.) 
     The Cellular device  105  is configured with a satellite radio receiver  106  coupled with a communication bus  116  for receiving signals from communication satellites  101 , a GPS/GNSS receiver  107  coupled with bus  116  for receiving radio navigation signals from global navigation satellites  102  and for deriving a position of cellular device  105  based thereon. Cellular device  105  further comprises an FM radio receiver  108  coupled with bus  116  for receiving broadcast signals from terrestrial radio broadcast  103 . Other components of cellular device  105  comprise a processor  109  coupled with bus  116  for processing information and instructions, a memory  110  coupled with bus  116  for storing information and instructions for processor  109 . It is noted that memory  110  can comprise both volatile memory and non-volatile memory, as well as removable data storage media in accordance with various embodiments. 
     Cellular device  105  further comprises a cellular transceiver  111  coupled with bus  116  for communicating via cellular network  122 . Examples of cellular networks used by cellular device  105  include, but are not limited to GSM: cellular networks, GPRS cellular networks, GDMA cellular networks, and EDGE cellular networks. Cellular device  105  further comprises a display  112  coupled with bus  116 . Examples of devices which can be used as display  112  include, but are not limited to, liquid crystal displays, LED-based displays, and the like. It is noted that display  112  can be configured as a touch screen device (e.g., a capacitive touch screen display) for receiving inputs from a user as well as displaying data. Cellular device  105  further comprises an audio output  113  coupled with bus  116  for conveying audio information to a user. Cellular device  105  further comprises a Wi-Fi transceiver  114  and an inertial measurement unit (IMU)  115  coupled with bus  116 . Wi-Fi transceiver  114  may be configured to operate on any suitable wireless communication protocol including, but not limited to WiFi, WiMAX, implementations of the IEEE 802.11 specification, implementations of the IEEE 802.15.4 specification for personal area networks, and a short range wireless connection operating in the Instrument Scientific and Medical (ISM) band of the radio frequency spectrum in the 2400-2484 MHz range (e.g., implementations of the Bluetooth® standard). 
     Corrected Pseudorange Position Determination: DGPS 
     Improvements in GNSS/GPS positioning may be obtained by using reference stations with a fixed receiver system to calculate corrections to the measured pseudoranges in a given geographical region. Since the reference station is located in a fixed environment and its location can be determined very precisely via ordinary survey methods, a processor associated with the Reference Station GNSS/GPS receivers can determine more precisely what the true pseudoranges should be to each satellite in view, based on geometrical considerations. Knowing the orbital positions via the GPS almanac as a function of time enables this process, first proposed in 1983, and widely adopted ever since. The difference between the observed pseudorange and the calculated pseudorange for a given reference station is called the pseudorange correction. A set of corrections for all the global navigation satellites  102  in view is created second by second, and stored, and made available as a service, utilizing GPS/GNSS reference stations  120  and correction services  121 . The pseudoranges at both the cellular device  105  GPS receiver  107  and those at the reference stations  120  are time-tagged, so the corrections for each and every pseudorange measurement can be matched to the local cellular device pseudoranges. The overall service is often referred to as Differential GPS, or DGPS. 
     Without any corrections, GNSS/GPS receivers produce position fixes with absolute errors in position on the order of 4.5 to 5.5 m per the GPS SPS Performance Standard, 4 th  Ed. 2008.  FIG. 2  depicts correction services  121  conveying these corrections via a cellular network  122 , or the Internet  123 . Internet  123  is in turn coupled with a local Wi-Fi network  124  which can convey the corrections to cellular device  105  via Wi-Fi transceiver  114 . Alternatively, cellular network  122  can convey the corrections to cellular device  105  via cellular transceiver  111 . In some embodiments, correction services  121  are also coupled with a distribution service  125  which conveys the corrections to an FM radio distributor  126 . FM radio distributor  126  can broadcast corrections as a terrestrial radio broadcast  103 . It should be appreciated that an FM signal is being described as a subset of possible terrestrial radio broadcasts which may be in a variety of bands and modulated in a variety of manners. 
     In some embodiments, cellular device  105  includes one or more integral terrestrial radio antennas associated with integrated terrestrial receivers; FM radio receiver  108  is one example of such a terrestrial receiver which would employ an integrated antenna designed to operate in the correct frequency band for receiving a terrestrial radio broadcast  103 . In this manner, in some embodiments, cellular device  105  can receive the corrections via FM radio receiver  108  (or other applicable type of integrated terrestrial radio receiver). In some embodiments, correction services  121  are also coupled with a distribution service  125  which conveys the corrections to a satellite radio distributor  127 . Satellite radio distributor  127  can broadcast corrections as a broadcast from one or more communications satellites  101 . In some embodiments, the cellular device  105  includes one or more integral satellite radio antennas associated with integrated satellite radio receivers  106 . Satellite radio receiver  106  is one example of such a satellite receiver which would employ an integrated antenna designed to operate in the correct frequency band for receiving a corrections or other information broadcast from communication satellites  101 . In this manner, in some embodiments, a cellular device  105  can receive the corrections via satellite radio receiver  106 . 
     Many more sophisticated GNSS/GPS receivers have been designed to accept and implement DGPS corrections. However, many of the chipsets embedded in millions of existing cellular devices are not configured to support this correction method. In fact, they are not configured to even make pseudorange measurement data available to the cellular device internally. Conventionally, pseudorange data from these cellular device chipsets are only available under a limited set of conditions, usually only when performing a 911 service call, and then only for use by the Assisted GPS service located in conjunction with the E-911 service facility. Newer generations of chipsets may be configured to make use of differential corrections available from the Satellite-Based Augmentation Service, or SBAS. Various embodiments of the present technology describe ways to operate with these newer chipsets and will be discussed subsequently. The limitation of unavailability of pseudoranges from embedded GNSS/GPS chipset technology in conventional cellular telephones or other handheld devices may be overcome as described herein. The protocol defined by the Open Mobile Alliance for use in mobile phones for determining location based on an internal GPS chipset and other resources is called the Secure User Plane Location, abbreviated “SUPL.” New software elements including algorithms for use in this kind of protocol are described herein. 
     Obtaining Pseudoranges from a Cellular Device GPS Chipset 
     According to various embodiments, the system depicted in  FIG. 2  provides components for implementing improved GPS/GNSS accuracy for a cellular device. It is noted that while the following discussion is directed to cellular devices specifically, embodiments are not limited to this use alone and can be implemented upon other mobile devices including, but not limited to, laptop computers, tablet computers, personal digital assistants (PDAs), handheld electronic devices, mobile navigation systems, and the like. For the purpose of brevity, like components described above with reference to  FIG. 2  will not be described again in the present discussion. In accordance with various embodiments, a cellular device  105  is provided with a plurality of Application Programming Interface (API) function applications stored in cellular device memory and each are configured to be operated by processor  109  upon activation by the user, or automatically. 
     In  FIG. 2 , the cellular device  105  is configured with a pseudorange fetch component  221 , a pseudorange correction fetch component  222 , a pseudorange corrector  223 , an augmented position determiner  224 , a carrier phase fetch component  225 , and a carrier phase smoothing component  226 . In  FIG. 2 , pseudorange fetch  221  is configured to request a current set of pseudoranges from the GNSS/GPS receiver  107  generated by and resident in the cellular device  105 . According to various embodiments, there are two methods for performing this request. In one embodiment, a 911 call function is activated which causes the GNSS/GPS receiver  107  to respond and put the current pseudoranges on the cellular device bus  116 . These local pseudoranges are stored in memory and made available to components of the cellular device  105 , such as the pseudorange corrector  223 . Another embodiment can employ a fetch routine sanctioned and adopted by the SUPL Committee on cellular operations. Chipsets in the future will have built-in capability to respond to requests and output pseudoranges with time tags, as is available in more expensive chipsets used in non-cellular device products. 
     According to one embodiment, pseudorange fetch  221  notifies the pseudorange corrector  223  that the pseudorange information is being stored. According to one embodiment, the cellular device  105  receive pseudorange corrections directly from an improvement service, such as a correction feed  640 , correction service  121 , correction service  121 , FM radio distribution  126 , or satellite radio distributor  127 , or a combination thereof, that is located outside of the cellular device, for example, without those pseudorange corrections being transmitted to the cellular device  105  through the GPS/GNSS chipset or receiver  107 . 
     In one embodiment, in response to a positioning activity with cellular device  105  communication system  220  notifies the pseudorange correction fetch  221  to test to see if pseudorange corrections are in memory already, and if not notifies the pseudorange correction fetch that pseudorange corrections need to be fetched from an improvement source, such as a correction feed  640 , correction service  121 , correction service  121 , FM radio distribution  126 , or satellite radio distributor  127 , or a combination thereof. 
     According to one embodiment,  FIG. 2  depicts a cellular telephone  104  that includes memory  110  coupled with a bus  116 , a Global Positioning System/Global Navigation Satellite System (GPS/GNSS) embedded receiver  107  coupled with the bus  116 , a communications system  220  coupled with the bus  116 , and a processor  109  coupled with the bus  116 , wherein the processor  109  is configured to obtain pseudoranges indirectly from the GPS/GNSS embedded receiver  107  and to receive differential corrections via the communications system  220  and provide a position fix of the cellular telephone  105  based on processing of pseudoranges and the differential corrections. 
     According to one embodiment, the pseudoranges from the GPS/GNSS embedded receiver  107  are obtained by a command from the processor  109  to the GPS/GNSS embedded receiver  107  via a thin Secure User Platform Location (SUPL). According to one embodiment, the pseudoranges are obtained via a command emulating an initiated 911 call and activating an E-911 transmission, in order to activate and receive pseudorange delivery from a GNSS/GPS chipset that is part of the cellular telephone  105 , and deactivating the E-911 transmission before the pseudoranges are transmitted to an emergency service. According to one embodiment, the pseudoranges are obtained by a command supported by a Secure User Platform Location (SUPL). According to one embodiment, the communications system  220  is a part of the cellular phone  105  and, therefore, is a cellular telephone system. 
     The blocks that represent features in  FIGS. 1 and 2  can be arranged differently than as illustrated, and can implement additional or fewer features than what are described herein. Further, the features represented by the blocks in  FIGS. 1 and 2  can be combined in various ways. The cellular device  100  or  105  can be implemented using hardware, hardware and software, hardware and firmware, or a combination thereof. 
     Examples of Methods for Obtaining Pseudorange Information 
       FIG. 3  depicts a flowchart of a method for obtaining pseudorange information using a cellular device, according to one embodiment. 
     The following description shall refer to  FIG. 1 . 
     At  310 , the method begins. 
     At  320 , the cellular device  100  accesses the GPS/GNSS chipset  170  that is embedded within the cellular device  100 . The GPS/GNSS chipset  170  calculates pseudorange information for use by the GPS/GNSS chipset  170 . For example, the GPS/GNSS receiver  107  can perform GPS measurements to derive raw measurement data for a position of the cellular device  100 . The raw measurement data provides an instant location of the cellular device  100 . The GPS/GNSS chipset  170  calculates pseudorange information that is for use by the GPS/GNSS chipset  170 . According to one embodiment, the raw measurement data is the pseudorange information that will be extracted. Examples of pseudorange information are uncorrected pseudorange information, differential GNSS corrections, high precision GNSS satellite orbital data, GNSS satellite broadcast ephermis data, and ionosopheric projections. 
     A chipset accessor  141 , according to one embodiment, is configured for accessing the GPS/GNSS chipset  170 . According to one embodiment, the chipset accessor  141  is a part of an SUPL client  701 . For example, the SUPL client  701  can interface between the GPS/GNSS chipset  170  and the location manager  161 , which resides in the operating system  160 . The pseudorange information can be obtained from the processor  172  of the GPS/GNSS receiver  107  using a command via a high precision Secure User Platform Location (SUPL). According to one embodiment, the GPS/GNSS chipset  170  is accessed using an operation that is a session started with a message that is an improved accuracy Secure User Platform Location (SUPL) start message or a high precision SUPL INIT message. According to one embodiment, the message is a custom command that is specific to the GPS/GNSS chipset  170  and the improved accuracy SUPL client  701  can have access to the raw measurements of the GPS/GNSS chipset  170 . 
     At  330 , the cellular device  100  extracts the pseudorange information from the GPS/GNSS chipset  170  for use elsewhere in the cellular device  100  outside of the GPS/GNSS chipset  170 . For example, a pseudorange information extractor  142  may be associated with a worker thread of the SUPL client  701 . The worker thread can watch over the raw measurements delivered by the GPS/GNSS chipset  170  into the GPS/GNSS chipset  170 &#39;s memory buffers and cache the raw measurements. 
     According to one embodiment, the raw measurement data is the pseudorange information that is extracted. According to one embodiment, the raw measurement data is pseudorange information that is calculated by the GPS/GNSS chipset  170  and is only for use by the GPS/GNSS chipset  170 . 
     At  340 , the method ends. 
     The extracted pseudorange information without further improvements can be used to provide an instant location. The extracted pseudorange information can be improved by applying pseudorange corrections, carrier wave information, or additional information, as described herein. The instant location or the improved location can be communicated to a location manager  162 , as discussed herein, that displays the instant location or the improved location with respect to a map. 
       FIGS. 4A and 4B  depict a flowchart  400  of a method for processing pseudorange information, according to one embodiment. 
     The following description shall refer to  FIG. 1 . 
     At  402 , the method begins. 
     At  404 , the requested mode is analyzed. 
     At  406 , if requested mode specifies determining the location without applying improvements or if the cellular device is not capable of applying improvements, then at  408 , the extracted pseudorange information is provided to the augmented position determiner  224  at  420 , which performs a least squared function on the extracted pseudorange information. Otherwise, processing proceeds to  410 . 
     At  410 , if the requested mode specifies determining an improved location by applying improvements, then at  412  the characteristics of the GPS/GNSS chipset  170  are determined. For example, a determination can be made as to which of the pseudorange corrections or carrier phase information provided by the chipset  170  would provide the higher accuracy based on the GPS/GNSS chipset  170 &#39;s characteristics. Otherwise, processing proceeds to  413 . 
     If at  413  it is determined that the GPS/GNSS chipset  170 &#39;s characteristics indicate that the pseudorange corrections would provide the higher accuracy, then at  414  a quality of position (QOP) position metric is used to determine whether to improve pseudorange information by applying pseudorange corrections. Otherwise, processing proceeds to  415 . For example, a QOP position metric can be determined from data obtained from the GPS/GNSS receiver  107 . If the QOP position metric is less than a pre-determined QOP, then at  416 , pseudorange corrections are requested from an improvement source and the extracted pseudorange information is provided to the pseudorange corrector  223  which will apply pseudorange corrections to the extracted pseudorange information. Processing proceeds to operation  420  where a least squared function is performed on the corrected pseudoranges. 
     If at  415  it is determined that the GPS/GNSS chipset  170 &#39;s characteristics indicate that the carrier wave information would provide the higher accuracy, then at  418  the extracted pseudorange information is provided to the carrier phase smoothing  226 , which applies the carrier wave information to the extracted pseudorange information resulting in smoothed pseudoranges. Processing proceeds to  420  where the augmented position determiner  224  performs a least squared function on the smoothed pseudoranges. 
     At  420 , the extracted pseudorange information from  408 , the corrected pseudoranges from the pseudorange corrector  223  from  416 , or the smoothed pseudoranges from the carrier phase smoothing  226  are provided at  420  to the augmented position determiner  224 , which performs a least squared function on the received input. 
     According to one embodiment, the additional information applicator  151  can apply additional information to extracted pseudorange information, which are uncorrected and unimproved, corrected pseudoranges, or smoothed pseudoranges, for example, prior to being communicated to the augmented position determiner  224 . 
     At  422 , the method ends. 
     The pseudorange information bridger  143  can provide the output of the augmented position determiner  224  to the location manager  161  that resides in the operating system  160 . The location displayer  162  of the location manager  161  can display the location with respect to a map. 
       FIG. 5  is a flowchart  500  of a method for performing a pseudorange fetch operation in accordance with one embodiment. 
     The following description shall refer to  FIG. 2 . 
     In various embodiments, pseudorange fetch  221  is the starting point for entering the augmented accuracy mode of operation and implements the operations of method described below in the context of flowchart  500 . In one embodiment, there is a program listing available for the augmented accuracy mode of operation, as any ordinary application is made available, to a user of a cell phone such as an Android™, iPhone, or similar cell phone configured to utilize applications. Upon selecting this function and pressing a Start button, the following operations are performed. 
     In operation  501  of  FIG. 5 , a message is sent to the GPS/GNSS receiver  107  to initiate an E911 activity. As described above, pseudorange measurement data is typically not available internally to a cellular device  105 , but can be made available when performing a 911 service call for use by the Assisted GPS service located in conjunction with the E911 facility. In operation  501 , initiating an E911 activity enables placement of pseudorange measurement data onto the signal bus  116  of cellular device  105  for access by other components. 
     In operation  502  of  FIG. 5 , pseudorange data is received from the GPS/GNSS receiver  107  and stored on a continuous basis until terminated. In one embodiment, the pseudorange data is continuously received and stored (e.g., in memory  110 ) while the E911 activity is active. This makes the pseudorange data available for an extended period to components of cellular device  105 . In one embodiment, pseudorange fetch  221  can retrieve the pseudorange data from memory  110 . 
     In operation  503  of  FIG. 5 , a pseudorange corrector  223  is notified that pseudoranges are being stored. In one embodiment, pseudorange corrector  223  receives a message from pseudorange fetch  221  that pseudorange data is available for processing. 
     In operation  504  of  FIG. 5 , pseudorange correction fetch  222  is notified to determine if pseudorange corrections are in memory already, or need to be fetched from an improvement service. As will; be discussed in greater detail, pseudorange correction fetch  222 , is configured to download pseudorange corrections from any of a variety of improvement source via any of several communications paths available to cellular device  105 . In one embodiment, pseudorange fetch  221  generates a message to pseudorange correction fetch  222  to determine whether pseudorange corrections are already stored in memory  110 , or need to be downloaded from an improvement source. 
     In operation  505  of  FIG. 5 , an E911 activity cancellation is initiated. In one embodiment, once pseudorange correction fetch  222  is notified to search for pseudorange corrections, the E911 activity is cancelled. According to one embodiment, this prevents actually completing a 911 call from cellular device  105  and inadvertently initiating an emergency response. 
     Obtaining and Processing Supplementary Data 
       FIG. 6  shows components for implementing secure user plane location in accordance with one embodiment. 
     The description of  FIG. 6  shall also refer to  FIG. 2 . 
     As described above, various embodiments are directed to improving the accuracy of position determination in cellular devices. In various embodiments, a number of data elements from onboard GPS/GNSS receiver  107 , as well as other sensors, are used to provide data to a positioning engine. In accordance with various embodiments, the Secure User Platform Location protocol (SUPL) is used as the positioning protocol as well as the way to provide assistance and corrections to GPS/GNSS receiver  107  and for transferring the measurements being made to a cellular device  105  to the positioning engine. SUPL is a protocol defined by the Open Mobile Alliance for use in cellular devices  105  for determining the position of the cellular devices. In  FIG. 6 , global navigation satellites  102  are used to provide navigation signals as described above. Location based applications refers to applications resident upon a cellular device  105  which is configured as a SUPL enabled terminal in accordance with various embodiments. While shown as resident upon cellular device  105 , location based applications  620  may reside elsewhere upon a network and may interact with cellular device  105  remotely. 
     In one embodiment, a SUPL Location Platform (SLP)  630  provides the back-end infrastructure needed to implement SUPL. Typically, SLP  630  is hosted by a network operator (e.g., the operator of cellular network  122 ) and handles the SUPL transaction with cellular device  105  to provide services such as E911, notifications, and verification. Corrections feeds  640  such as Real Time Kinematic (RTK) feeds and/or Differential GPS (DGPS) feeds comprises a service (e.g., correction services  121 ) which can provide data for improving the precision in determining the position of cellular device  105 . This data may include, but is not limited to, high precision orbital data rather than or in addition to broadcast ephemeris data, DGPS corrections, improved ionospheric projections rather than a standard Kloubuchar model, accurate clock data, and other Real-Time Kinematics data that helps in precisely determining the position of cellular device  105 . 
       FIG. 7  is a block diagram showing components of an improved accuracy SUPL client in accordance with one embodiment. 
     The following description of  FIG. 7  shall refer to  FIG. 2 . 
     In  FIG. 7 , improved accuracy SUPL client comprises a positioning engine  705 , profiler  720 , connections manager  730 , and configuration manager  740 . It is noted that improved accuracy SUPL client  701  is shown as resident in memory  110  of cellular device  105  in accordance with various embodiments. Positioning engine  705  determines the position of cellular device  105  using raw GPS/GNSS measurements and cues from various sensors in cellular device  105 . In accordance with one embodiment, positioning engine  705  is implemented as augmented position determiner  224 . In accordance with various embodiments, positioning engine  705  can use data provided by, for example, corrections feeds  640 . In accordance with various embodiments, positioning engine  705  can utilize algorithms to cancel multi-path signals, ground reflections and other echo, capacitance of the bearer and boost faint or broken signals. Positioning engine  705  can also query map engine  715  to obtain data about the surroundings. For example, positioning engine  705  can perform a first coarse positioning of cellular device  105  and then query map engine  715  about the area around the current position of cellular device  105 . A rough description of the area around a cellular device  105  (e.g., how far away are walls surrounding the cellular device  105 ) can help determine the degree of signal processing that needs to be performed upon signals received from global navigation satellites  102 . In accordance with one embodiment, positioning engine  705  can apply this algorithm iteratively until a desired quality of precision (QOP) is achieved. Profiler  720  is a component used by SUPL client  701  to understand the characteristics of the GPS/GNSS silicon and the other sensors present in the system. This process includes calibration and detection of feature set and capabilities of these components. This process could be initiated at the time of installation into cellular device  105 , when first started or after a software, firmware or hardware upgrade to cellular device  105  or when the stored data is lost. This process could be triggered selectively or as a whole. It could also be triggered when new capabilities are expected by the SUPL Client  701 . In addition to characterization of the device, this process also helps in identification of the command and data set of the GPS/GNSS receiver  107  and usage of the appropriate APIs. In one embodiment, the connections manager  730  is used by SUPL Client  701  to manage the connections with the components available on the network, for example the secure location platform  630 , corrections feeds  640 , and other data feeds. In one embodiment, configuration manager  740  stores the current operational parameters of SUPL Client  701  as mandated by the specification and other means. The configuration manager  740  also determines the degree of operation of the Positioning Engine  705 . 
     Also shown in  FIG. 7  are devices and data sources which provide data to position engine  705  in determining the position of cellular device  105 . These include, but are not limited to, cellular transceiver  111 , Wi-Fi transceiver  114 , GPS/GNSS receiver  107 , accelerometer  711 , compass  712 , gyroscope  713 , a Bluetooth Low Energy (BLE) component  714 , and map engine  715 . It is noted that accelerometer  711  and gyroscope  713  may be integrated as IMU  115 . 
     BLE component  714  refers to a low energy wireless radio technology which is intended for use in mobile devices such as cellular telephones. BLE component  714  is an example a short range, low energy wireless personal area networking component which typically operates and exchanges data wirelessly over short distances using short-wavelength radio transmissions in the ISM band (from 2400-2480 MHz) from fixed and/or mobile devices. 
       FIG. 8  depicts a flowchart  800  of a method for obtaining pseudorange information using a cellular device, according to one embodiment. According to one embodiment, the method depicted by flowchart  800  provides various embodiments for implementing corrections operations. 
     At  802 , the method begins. 
     At  804 , a Secure User Platform Location (SUPL) operation is initiated using a custom command that is specific to the GPS/GNSS chipset. The pseudorange information is accessed by a chipset accessor  141  ( FIG. 1 ) and extracted by a pseudorange information extractor  142  ( FIG. 1 ) using a custom command that is specific to the GPS/GNSS chipset  170  ( FIG. 1 ), according to one embodiment. 
     At  806  a determination is made as to whether the GPS/GNSS receiver  107  needs assistance in determining a position of the cellular device  100  ( FIG. 1 ) or  105  ( FIG. 2 ) to achieve a desired level of Quality of Position (QOP). 
     At  812 , if the GPS/GNSS receiver needs assistance, then additional data is received from satellites currently in view of the GPS/GNSS receive  107  ( FIGS. 1 and 2 ). Examples of addition data are acquisition assistance data, high precision ephemeris data, and DGPS/DGNSS corrections). 
     At  816 , the DGPS corrections are provided to the GPS/GNSS receiver  107 . For example, the DGPS corrections data (e.g., as well as the other data received in operation  812 ) are provided to the GPS/GNSS receiver  107  ( FIGS. 1 and 2 ). 
     At  818 , GPS measurements are performed at the GPS/GNSS receiver  107  to derive raw measurement data of a position of the cellular device  100  ( FIG. 1 ) or  105  ( FIG. 2 ). For example, GPS/GNSS receiver  107  ( FIGS. 1 and 2 ) performs GPS measurements to derive raw measurement data of the position of cellular device  100  ( FIG. 1 ) or  105  ( FIG. 2 ). 
     At  820 , carrier phase and pseudorange signals are measured from one or more satellites that are in view of the GPS/GNSS embedded receiver  107  ( FIGS. 1 and 2 ). For example, an operation in which carrier phase and pseudorange measurements of signals from each satellite in view of GPS/GNSS receiver  107  ( FIGS. 1 and 2 ) is performed. 
     At  822 , additional information is obtained from one or more of a compass, gyroscope, accelerometer, and a source accessed via a wireless communication protocol operating in the range of frequencies between 2402-2480 MHz, such as, such as Bluetooth Low Energy (BLE)®. For example, data from compass  712 , gyroscope  713 , accelerometer  711 , and/or BLE  714  ( FIG. 7 ) is obtained. In one embodiment, improved accuracy SUPL client  701  ( FIG. 7 ) obtains accumulated data from various sensors that may be resident upon cellular device  100  ( FIG. 1 ) or  105  ( FIG. 2 ) such as gyroscope  713 , accelerometer  711  (e.g., IMU  115 ), compass  712  ( FIG. 7 ), etc., for the past n seconds. In accordance with one embodiment, if indoor positioning is enabled improved accuracy SUPL client  701  ( FIG. 7 ) obtains readings from BLE radios that may be present in the area. 
     At  824 , the data from the compass, gyroscope, accelerometer, and the BLE are sent. For example, the data from compass  712 , gyroscope  713 , accelerometer  711 , and/or BLE  714  ( FIG. 7 ) is sent by improved accuracy SUPL client  701  ( FIG. 7 ). 
     At  828 , a more precise location of the cellular device  100  ( FIG. 1 ) or  105  ( FIG. 2 ) is generated based on the corrected data. For example, positioning engine  705  ( FIG. 7 ) processes the data received in operation  824 . In one embodiment, positioning engine  705  uses the positioning cues provided from these inputs (e.g., compass  712 , gyroscope  713 , accelerometer  711 , and/or BLE  714 ) to generate a precise position of cellular device  100  ( FIG. 1 ) or  105  ( FIG. 2 ). In one embodiment, operations  818 ,  820 ,  822 ,  824 ,  824  are repeated until a desired Quality of Positioning (QOP) level is achieved in determining the position of cellular device  100  ( FIG. 1 ) or  105  ( FIG. 2 ). 
     If an E-911 call is used to initiate the operation, then at  830 , the pseudorange information is prevented from being delivered to the originally intended recipient, such as an emergency service, according to one embodiment, by terminating the SUPL operation before the pseudorange information is delivered to the originally intended recipient. For example, the SUPL session using improved accuracy SUPL client  701  ( FIG. 7 ) is terminated at  830 . 
     If a GPS/GNSS chip custom command is used to initiate the operation, then, at  830 , the pseudorange information is accessed by the chipset accessor  141  ( FIG. 1 ) and extracted by the pseudorange information extractor  142  ( FIG. 1 ), as discussed herein. 
     In one embodiment, one the position of cellular device  100  ( FIG. 1 ) or  105  ( FIG. 2 ) is determined within the desired QOP parameters, the position of cellular device  100  ( FIG. 1 ) or  105  ( FIG. 2 ) is delivered to the application which generated a request of the position of cellular device  100  ( FIG. 1 ) or  105  ( FIG. 2 ). 
     At  832 , the method ends. 
     According to one embodiment, an E-911 call is used to obtain pseudorange information from a GPS/GNSS chipset. The following is a description of flowchart  800  in the event that E-911 call is used. 
     At  802 , the method begins. 
     At  804 , a Secure User Platform Location (SUPL) operation is initiated that is intended for delivering the pseudorange information from the GPS/GNSS receiver of the cellular device to a recipient originally intended by the operation. According to one embodiment, operation  420  further comprises operation  804 . Examples of pseudorange information are uncorrected pseudorange information, pseudorange corrections from correction feeds, high precision orbital data, broadcast ephemeris data, Differential GPS (DGPS) corrections, and improved ionosphere projections. According to one embodiment, the operation is a session that is started with a message selected from a group consisting of a Secure User Platform Location (SUPL) start message and an SUPL INIT message. The pseudorange information is accessed and redirected to the different recipient that was not originally intended by the operation. 
     The other operations  806 ,  812 ,  816 ,  818 ,  820 ,  822 ,  824 ,  826 ,  828  are performed as described herein. 
     At  830 , the pseudorange information is prevented from being delivered to the originally intended recipient by terminating the SUPL operation before the pseudorange information is delivered to the originally intended recipient. For example, the SUPL session using improved accuracy SUPL client  701  is ended. 
     At  832 , the method ends. 
     Although specific operations are disclosed in flowcharts  300 ,  400 ,  500 , and  800 , such operations are exemplary. That is, embodiments of the present invention are well suited to performing various other operations or variations of the operations recited in flowcharts  300 ,  400 ,  500 , and  800 . It is appreciated that the operations in flowcharts  300 ,  400 ,  500 , and  800  may be performed in an order different than presented, and that not all of the operations in flowcharts  300 ,  400 ,  500 , and  800  may be performed. 
     Non-Transitory Computer Readable Storage Medium 
     Any one or more of the embodiments described herein can be implemented using non-transitory computer readable storage medium and computer-executable instructions which reside, for example, in computer-readable storage medium of a computer system or like device. The non-transitory computer readable storage medium can be any kind of memory that instructions can be stored on. Examples of the non-transitory computer readable storage medium include but are not limited to a disk, a compact disk (CD), a digital versatile device (DVD), read only memory (ROM), flash, and so on. As described above, certain processes and operations of various embodiments of the present invention are realized, in one embodiment, as a series of instructions (e.g., software program) that reside within non-transitory computer readable storage memory of a computer system and are executed by the computer processor of the computer system. When executed, the instructions cause the computer system to implement the functionality of various embodiments of the present invention. According to one embodiment, the non-transitory computer readable storage medium is tangible. 
     The following description of a non-transitory computer readable storage medium, according to various embodiments, refers to  FIG. 1 . According to one embodiment, a non-transitory computer readable storage medium is provided that comprises instructions, which when executed causes a processor  109  of a cellular device  100 , which is not a part of an embedded Global Positioning System/Global Navigation Satellite System (GPS/GNSS) receiver  107  of the cellular device  100 , to perform a method for obtaining pseudorange information using a cellular device  100 . The method comprises accessing, performed by the cellular device  100 , a GPS/GNSS chipset  170  embedded within the cellular device  100 , wherein the GPS/GNSS calculates pseudorange information for use by the GPS/GNSS chipset  170 ; and extracting, performed by the cellular device  100 , the pseudorange information from the GPS/GNSS chipset  170  for use elsewhere in the cellular device  100  outside of the GPS/GNSS chipset  170 . A location of the cellular device  100  can be determined based on the pseudorange information. A pseudorange correction fetch  222  ( FIG. 2 ) is notified to test to see if pseudorange corrections are in memory  110  ( FIG. 2 ) already. The pseudorange corrections are received directly from an improvement source that is located outside of the cellular device  100 . The pseudorange information is processed in a portion of the cellular device  100  that is outside of the GPS/GNSS chipset  170  to determine a position fix of the cellular device  100 . The pseudorange information is processed using one or more Application Programming Interface (API) function applications that reside in memory of the cellular device  100  and are executed by the processor  109  of the cellular device  100 . Additional information is obtained from one or more of a compass, gyroscope, accelerometer, and a source accessed via a WiFi or via a short range wireless communication protocol operating in the range of frequencies between 2402-2480 MHZ. Corrected data is created based on the obtained additional information and a location of the cellular device  100  is generated based on the corrected data. The pseudorange information extractor extracts at least four pseudorange measurements as a part of extracting the pseudorange information from the GPS/GNSS chipset  170 . A quality of position (QOP) position metric is determined from data obtained from a GPS/GNSS receiver  107  associated with the GPS/GNSS chipset  170 . If the QOP position metric is less than a pre-determined QOP, then pseudorange corrections are requested from an improvement source. 
     CONCLUSION 
     Example embodiments of the subject matter are thus described. Although the subject matter has been described in a language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims. 
     Various embodiments have been described in various combinations and illustrations. However, any two or more embodiments or features may be combined. Further, any embodiment or feature may be used separately from any other embodiment or feature. Phrases, such as “an embodiment,” “one embodiment,” among others, used herein, are not necessarily referring to the same embodiment. Features, structures, or characteristics of any embodiment may be combined in any suitable manner with one or more other features, structures, or characteristics.