Ex Parte Meyers et alDownload PDFPatent Trial and Appeal BoardNov 24, 201412709657 (P.T.A.B. Nov. 24, 2014) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte DAVID W. MEYERS, LAWRENCE C. VALLOT, BRIAN SCHIPPER, and KELLY MULDOON ____________ Appeal 2012-010189 Application 12/709,6571 Technology Center 3600 ____________ Before EDWARD A. BROWN, BRANDON J. WARNER, and JAMES J. MAYBERRY, Administrative Patent Judges. BROWN, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE This is a decision on appeal under 35 U.S.C. § 134 from the Examiner’s rejection of claims 1–10. Appeal Br. 1. We have jurisdiction under 35 U.S.C. § 6(b). We reverse. 1 Appellants identify the real party in interest as Honeywell International Inc. Appeal Br. 1. Appeal 2012-010189 Application 12/709,657 2 Claimed Subject Matter Claims 1, 4, and 8 are independent. Claim 1, reproduced below, is illustrative of the claimed subject matter: 1. A method for the execution of a GPS RAIM algorithm to eliminate the time unknown of the GPS solution and thus reducing the number of required satellite measurement sets by one, the method comprising: deriving position, velocity, and time solutions from a GPS navigation system derived from a plurality of satellite ephemerides and measurements; receiving an atomic clock signal from one or more atomic clocks located in the navigation system; comparing the atomic clock signal to the derived time solutions to derive a correction factor; adjusting the atomic clock signal according to the correction factor to develop an adjusted atomic clock signal; and using the adjusted atomic clock signal to remove the clock unknown of the GPS RAIM solution and thus reducing the number of required satellite measurement sets by one. Rejection Claims 1–10 stand rejected under 35 U.S.C. § 103(a) as being unpatentable over Turney (US 5,615,236, issued Mar. 25, 1997) and Bruckner (US 6,317,688 B1, issued Nov. 13, 2001). ANALYSIS Appellants’ Specification describes that RAIM (Receiver Autonomous Integrity Monitoring) is used to assess the integrity of GPS (Global Positioning System) signals in a GPS receiver system. Spec. ¶ 2. In particular, RAIM detects faults by utilizing redundant GPS pseudorange measurements (i.e., measurements from more satellites than are needed to Appeal 2012-010189 Application 12/709,657 3 produce a position fix) to determine whether all of the extra pseudoranges are consistent with the computed position. Id. ¶ 3. At least four measurements are required to obtain a three-dimensional position solution (id. ¶ 4), and conventional RAIM availability requires six or more satellite measurements (id. ¶ 5). Eliminating time as an unknown reduces the required number of satellites for the basic navigation solution from four to three, and allows RAIM Fault Detection and Exclusion (FDE) to be achieved with only five satellites. Id. Claims 1–3 Claim 1 is directed to a method for the execution of a GPS RAIM algorithm to eliminate the time unknown of the GPS solution and thus reduce the number of required satellite measurement sets (for execution of the algorithm) by one. The claimed method requires one fewer satellite to produce a navigation solution than does a conventional system that implements a RAIM algorithm. Appeal Br. 6. Claim 1 recites, inter alia, “adjusting the atomic clock signal according to the correction factor to develop an adjusted atomic clock signal,” and “using the adjusted atomic clock signal to remove the clock unknown of the GPS RAIM solution and thus reduc[e] the number of required satellite measurements sets by one.” Id. at 10, Claims App. The Examiner finds that Turney discloses adjusting a clock signal based on a correction factor, and using the adjusted clock signal to enhance the position estimate of the true current GPS time. Answer 4 (citing Turney, col. 4, ll. 6–8). The Examiner finds that Bruckner discloses a GPS RAIM Appeal 2012-010189 Application 12/709,657 4 algorithm using a GPS/IMU solution2 “to reduce (or without) the use of the number of required satellites.” Id. (citing Bruckner, col. 6, ll. 52–55). The Examiner concludes that it would have been obvious to incorporate the teaching of Bruckner’s system in Turney to have a GPS RAIM algorithm to enable the system to reduce the number of required satellites for positional information. Id. at 5. Turney discloses a method for re-acquiring P-code transmitted by satellites in a GPS receiver. See Turney, Abstract. Turney discloses satellite receiver 10 including clock 40, which receives periodic synchronizing data related to GPS satellite system time from processor 24. Id. at col. 3, ll. 51– 54; Fig. 1. Clock 40 maintains a running estimate of GPS time, and clock drift errors are corrected with the synchronizing data. Id. at col. 3, ll. 55–58. If P-code tracking is briefly lost by satellite receiver 10, to re-acquire it, Turney determines the drift of clock 40 by comparing it to a “more accurate time that is conventionally intrinsic to GPS-DSPs,”3 and adjusting the last time reading of clock 40 by a drift correction factor to produce “an enhanced estimate of the true current global positioning system time.” Id. at col. 4, ll. 4–9. Turney does not disclose use of RAIM. See Answer 4–5. Bruckner discloses a global navigation apparatus including a GPS receiver to provide GPS measurement data, an inertial sensor system to provide inertial translational and rotational data, and a navigation system coupled to the GPS receiver and inertial sensor system. See Bruckner, Abstract. Figure 6 depicts GPS receiver 710 and inertial sensors system 120 2 Bruckner describes an “inertial measurement unit (IMU).” See Bruckner, col. 2, l. 17. 3 Turney describes a “digital signal processor (DSP).” See Turney, col. 3, l. 19. Appeal 2012-010189 Application 12/709,657 5 for providing measurement data 712 and inertial data 121, respectively, to navigation solution apparatus 130. Id. at col. 6, ll. 40–56. Bruckner states, “[d]uring the time periods in which inertial sensors 120 provide inertial data 121 without the use of GPS data from GPS receiver 110, the navigation system 130 can utilize multi-GPS to form an attitude solution to produce navigation data 131 with increased accuracy.” Id. at col. 6, ll. 52–56. Appellants contend that the Examiner effectively ignores the limitation of “using the adjusted atomic clock signal to remove the clock unknown of the GPS RAIM solution and thus reducing the number of required satellite measurements sets by one,” as recited in claim 1. Appeal Br. 6. Appellants contend that Turney relates to re-acquiring P-code using an atomic clock, not to use of RAIM (id. (citing Turney, col. 4, ll. 6–8)), and Bruckner does not disclose how to implement RAIM with one fewer satellite measurement than in conventional RAIM (id. at 7). Appellants dispute that one skilled in the art would know how to use an adjusted atomic clock signal to reduce the number of satellites needed for a RAIM algorithm merely because Turney “uses an adjusted clock signal to ‘enhance a position estimate’ (through P-code reacquisition)” and Bruckner teaches the use of merely conventional (i.e., standard) RAIM. Id. In the Reply Brief, Appellants contend that the Examiner does not adequately explain why it would have been obvious to combine the teachings of Turney and Bruckner to produce a method that operates with one less satellite than a conventional RAIM method. Reply Br. 1–2. Appellants’ contentions are persuasive. Appellants correctly point out that Turney does not teach the use of RAIM. Appeal Br. 6. As discussed above, Turney corrects a clock signal in a GPS receiver using a satellite time Appeal 2012-010189 Application 12/709,657 6 signal (atomic clock signal), to be able to re-acquire P-code more efficiently following a power outage, as would occur when external power is removed or battery 36, which powers GPS receiver 10, dies or is replaced. See Turney, col. 3, l. 64–col. 4, l. 1. The Examiner does not identify any disclosure in Turney of using a corrected atomic clock signal, much less in a RAIM algorithm. As discussed above, Bruckner teaches use of a combination of GPS and inertial sensors to provide a navigation solution. The Examiner does not adequately explain how Bruckner’s description of providing “inertial data 121 without the use GPS data from GPS receiver 110” (col. 6, ll. 53–54) teaches using an adjusted atomic clock signal in a GPS RAIM algorithm for “reducing the number of required satellite measurement sets by one.” Regarding the Examiner’s finding that Bruckner discloses “without” “the use of the number of required satellites,” (see Answer 4) claim 1 recites that the method reduces the number of required satellite measurement sets by one, not that the method is performed “without” satellites. Thus, we agree with Appellants that the Examiner does not show that the combination of Turney and Bruckner meets each of the claimed limitations. Thus, we do not sustain the rejection of claim 1, or dependent claims 2 and 3. Claims 8–10 Claim 8 is directed to an apparatus for providing a timing signal to reduce the number of required satellite measurements by one in execution of a RAIM algorithm, comprising, inter alia, “a processor for executing the RAIM algorithm based upon the adjusted atomic clock signal to eliminate Appeal 2012-010189 Application 12/709,657 7 the time unknown of the GPS solution and thus reduce the number of required satellites by one.”4 Appeal Br. 11, Claims App. The Examiner finds that Bruckner discloses a RAIM algorithm processor to receive satellite measurements and the IMU solution from the GPS receiver to test the integrity of each satellite ephemeris. Answer 5 (citing Bruckner, col. 7, l. 47–col. 8, l. 15). The passage in Bruckner cited by the Examiner (col. 7, l. 47–col. 8, l. 15) describes “standard RAIM.” See Bruckner, col. 7, ll. 48–49. Bruckner further describes that “[a] modification to the standard RAIM described above is needed for the contribution we seek from the inertial augmentation.” See col. 8, ll. 20–22. This modification “takes the form of taking two components of position (horizontal) from the IMU solution, and one component of altitude from a baro-altimeter, and feeding these three as additional ‘measurements’ into the RAIM computation.” See Bruckner, col. 8, ll. 22–26. Appellants contend that Turney and Bruckner do not teach “a processor for executing the RAIM algorithm based upon the adjusted atomic clock signal to eliminate the time unknown of the GPS solution and thus reduce the number of required satellites by one,” as claimed. Appeal Br. 8. For reasons similar to those discussed above in regard to the rejection of claim 1, Appellants’ contentions for claim 8 are persuasive. Thus, we do not sustain the rejection of claim 8, or its dependent claims 9 and 10. 4 Although the preamble of claim 8 is directed to an “apparatus,” “the method comprising” is recited at line 2. In addition, the preambles of claims 9 and 10, which both depend from claim 8, recite “[t]he system of Claim 8.” In this appeal, for consistency, we treat claims 8–10 as being directed to an “apparatus.” Appeal 2012-010189 Application 12/709,657 8 Claims 4–7 Claim 4 recites a GPS navigation system including a RAIM processor, comprising, inter alia, “a RAIM algorithm processor to receive the satellite measurements and the time solutions from the GPS receiver and the corrected clock signal to test the integrity of each of the satellite ephemeris in the satellite ephemerides.” Appeal Br. 10–11, Claims App. The Examiner relies on the same findings and reasoning for claim 4, as those for claim 8 discussed above. Answer 4–5. For the reasons discussed above, we agree with Appellants that the Examiner does not show that the applied combination of Turney and Bruckner includes all of the limitations of claim 4, including, inter alia, a GPS navigation system including a RAIM algorithm processor that uses a corrected atomic clock signal to test the integrity of each of the satellite ephemeris in the satellite ephemerides. See Appeal Br. 8. Thus, we do not sustain the rejection of claim 4, or its dependent claims 5–7. DECISION We reverse the Examiner’s rejection of claims 1–10. REVERSED Klh Copy with citationCopy as parenthetical citation