DETAILED ACTION
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 2/17/2026 has been entered.
Response to Arguments
Applicant's arguments filed 2/17/2026 have been fully considered.
Regarding Applicant’s argument (page 10, second and third paragraphs) that the newly added features in claim 1 are not taught by the cited references, Examiner respectfully disagrees. Claims 1, 9, and 16 have been amended to recite the limitations of canceled claims 4, 12, and 19, which were rejected in the 12/17/2025 final rejection as unpatentable over Ferguson in view of Syrjarinne or Camp or Twitchell. Examiner maintains that the prior art teaches the features of these claims.
Regarding Applicant’s argument (last paragraph of page 10 and first paragraph of page 11) that Ferguson's "compromise notifier configured for providing a compromise notification to a user of said GNSS reference station" is a maintenance alert directed at a human operator or administrator to indicate that the reference station requires attention, and therefore Ferguson does not teach transmitting a data flag or indicator wirelessly to a mobile rover to inform the rover's positioning engine that the base station's signals are invalid. Examiner respectfully disagrees, as Ferguson para. [0060] teaches "Compromise notifier 350, when included, operates to generate a comprise notification message when compromise monitor 330 monitors the occurrence of a compromise to the operational integrity of reference station 120. This message is then provided to users of reference station 120. For example, transceiver 230 can transmit the compromise notification message to a rover receiver or to a network RTK information generator 130 to which reference station 120 provides information. This facilitates user awareness of potential problems that may exist with precise positioning applications" (emphasis added). Para. [0004] teaches that spoofing is an example of an integrity compromise. Ferguson therefore teaches wirelessly transmitting a spoofing indicator to a mobile rover as claimed.
Regarding Applicant’s argument (second paragraph of page 11) that, even if Ferguson teaches a rover indicator, Ferguson does not teach coupling this notification with the transmission of the safe server data to the rover, but instead teaches "the safe network data is used internally by the reference station to 'replace local over-the-air GNSS signals in the operation of said GNSS reference station' (Ferguson at claim 19)", and therefore "does not teach passing this safe data to the rover alongside the warning". However, the claims do not recite any "coupling" of the notification with the transmission of the safe server data, or that they as passed to the rover "alongside" each other. Further, Ferguson has not been relied upon to teach transmitting the safe ephemeris data from the base station to the rover, but Syrjarinne, Camp, and Twitchell.
Regarding Applicant's argument (third paragraph of page 11) that Syrjarinne, Camp, and Twitchell do not teach a "spoofing indicator", these references have not been relied upon to teach a spoofing indicator.
Regarding Applicant's argument (fourth paragraph of page 11) that the cited references do not teach "the base station actively detecting spoofing and transmitting a combined data stream (indicator + safe data) to the rover to manage the spoofing event", the claims do not recite a combined data stream. The amended claims recite transmitting a spoofing indicator and safe ephemeris data, but do not recite that they are "combined" in any way.
New claims 21-26 have been rejected in view of the prior art. Examiner notes that Applicant did not provide any arguments regarding these claims.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1, 2, 7-10, 15-17, 21, 23, 24, and 26 are rejected under 35 U.S.C. 103 as being unpatentable over Ferguson (US 20110285586 A1, cited on IDS) in view of [Syrjarinne (US 20070159387 A1) or Camp (US 6075987 A) or Twitchell (US 6222483 B1)].
Regarding claim 1, 9, and 16, Ferguson teaches [NOTE: limitations not taught by Ferguson are lined through; language added by amendment is underlined] a method of computing a position of a rover (160-i, Fig. 1B), the method comprising:
receiving safe ephemeris data (“precise orbit information” paras. [0042], [0056]) at a base station (any of reference stations 120-i, Figs. 1A-B, 2; para. [0056] “precise orbit… that is received in the network RTK information”, referring to receipt of precise orbit data by comparator 320 of integrity system 240 of a reference station 120), the safe ephemeris data having been sent from a server (Network RTK Information Generator 130, Fig. 1B in view of paras. [0041]-[0042], [0056]), the safe ephemeris data indicating positions of a plurality of satellites (inherent to orbit information);
receiving satellite signals at the base station (satellite signals 150-i are received at reference stations 120-i as shown in Fig. 1A) and obtaining reference ephemeris data therefrom (para. [0043] “observed orbit information that has been reported from another reference station... This is possible because broadcast orbit information remains static for periods of time and is identically received at other locations”, indicating that reference stations obtain orbit information from received satellite signals, in view of para. [0042] “satellite orbit information (ephemeris)”, indicating that the orbit information comprises ephemeris);
performing, at the base station, a comparison between the reference ephemeris data and the safe ephemeris data to determine whether the satellite signals received at the base station are spoofed signals (para. [0056] “comparator 320 compares the actual received satellite positions (or orbits calculated therefrom) with the over-the-air orbit information/precise orbit information” to determine “If there is no compromise to integrity”, where comparator 320 is part of reference station 120 as discussed above; claim 8 “performing said comparing at said GNSS reference station”);
based on the comparison, determining that the satellite signals received at the base station are spoofed signals (implied by para. [0060] “generate a… notification message when compromise monitor 330 monitors the occurrence of a compromise to the operational integrity of reference station 120”);
wirelessly transmitting, from the base station to the rover, (i) a spoofing indicator indicating that the satellite signals received at the base station are spoofed signals(para. [0060] “generate a… notification message when compromise monitor 330 monitors the occurrence of a compromise to the operational integrity of reference station 120. This message is then provided to users of reference station 120”);
receiving satellite signals at the rover having been transmitted by the plurality of satellites (signals 150-1…n from satellites SV1…n, Fig. 1B);
obtaining rover carrier phase measurements based on the satellite signals received at the rover (para. [0024] “positioning based on carrier phase measurements” and “measurements taken by a rover station”); and
computing the position of the rover using the rover carrier phase measurements (paras. [0024], [0027], [0044])
Ferguson does not teach wirelessly transmitting, from the base station to the rover, the safe ephemeris data that was previously received by the base station from the server, where the rover position is computed using the safe ephemeris. However, Ferguson teaches wirelessly transmitting other information from the base station to the rover – for example, para. [0024] “Measurements made at the reference station can then be transmitted from the reference station to the rover station” – and it is well-known for a base station to also transmit, to a rover, ephemeris data that has been received from a server. For example, see:
Syrjarinne Fig. 2 steps 201, 202, 103, 302 in view of para. [0037] “The common orbit model can be based on Keplerian orbits and parameters used for the GPS ephemeris”:
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Camp Fig. 1, showing server 18, base station 20, and user terminal 10, in view of 5:21-29 “ephemeris data”:
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Twitchell Fig. 2, showing server 56, base station 46, and remote unit 42, in view of 6:55 – 7:4 “ephemerides”, “ephemeris”:
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It would have been obvious to modify Ferguson by wirelessly transmitting the safe ephemeris data from the base station to the rover as taught by Syrjarinne, Camp, and Twitchell, in order to provide the rover with safe ephemeris data with which it can determine its position.
Regarding claims 2, 10, and 17 Ferguson teaches:
obtaining reference carrier phase measurements based on the satellite signals received at the base station (para. [0027] “carrier phases from… reference receivers”).
Regarding claims 7 and 15, Ferguson teaches receiving safe correction data at the base station (para. [0041] “RS120a… may receive network RTK information 135A (e.g. synthetic observables and/or other information) from network RTK information generator 130 that is specified for and specific to the location of RS 120a” where RS120a is the base station and at least the “synthetic observables” are considered correction data in view of para. [0033] “VRS corrections generator outputs… observables”), wherein the safe correction data is derived from a geographic-specific error model (para. [0040] “observables… may include… dominant observables errors comprising a receiver clock error, satellite clock errors, ionosphere and troposphere signal delay errors and noise all appear to be consistent with the specified position”); and wirelessly transmitting the safe correction data from the base station to the rover, wherein the position of the rover is computed further using the safe correction data (para. [0048] “communicating RTK corrections from a reference station to a rover receiver”; use of the corrections to determine rover position is described in para. [0024]).
Regarding claim 8, Ferguson teaches wherein the satellite signals received at the rover are transmitted by a plurality of Global Positioning System (GPS) satellites (satellites Sv1…n Fig. 1B).
Regarding claims 21 and 24, Ferguson teaches wherein performing the comparison comprises: calculating a position difference between a first satellite position derived from the reference ephemeris data and a second satellite position derived from the safe ephemeris data; and determining that the position difference exceeds a predetermined threshold (para. [0056] “comparator 320 includes satellite position comparator 323 which compares the actual received satellite positions (or orbits calculated therefrom) with the over-the-air orbit information/precise orbit information (or orbits calculated therefrom) that is received in the accessed network RTK information”; para. [0058] “comparisons should agree within some predefined non-zero threshold of difference”).
Regarding claims 23 and 26, Ferguson teaches wherein receiving the safe ephemeris data at the base station comprises receiving the safe ephemeris data via a terrestrial network connection or an Internet connection that is independent of the satellite signals (Accessor 310, Fig. 3 in view of para. [0053]; para. [0040] “broadcasts”; paras. [0036] and [0081] “Internet”).
Claims 6 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Ferguson (US 20110285586 A1, cited on IDS) in view of [Syrjarinne (US 20070159387 A1) or Camp (US 6075987 A) or Twitchell (US 6222483 B1)] as applied to claims 1 and 9 above, and further in view of Kaplan (“Understanding GPS Principles and Applications” Chapter 8 pages 379 and 380).
Regarding claims 6 and 14, Ferguson does not teach wirelessly transmitting a position of the base station from the base station to the rover, wherein the position of the rover is computed further using the position of the base station.
However it is well-known for a base station to transmit its position to a rover for use in a differential positioning system like Ferguson’s. For example see Kaplan page 379 “The reference station(s) provides information to the end user via a data link that may include:…. Auxiliary data including the location… of the reference stations(s)” and page 380 “For absolute differential positioning, each reference station’s position must be accurately known with respect to the same ECEF coordinate system in which the user position is desired”.
It would have been obvious to further modify Ferguson in view of Kaplan because it is a well-known feature of a differential positioning system that allows the rover to determine its absolute position.
Claims 22 and 25 are rejected under 35 U.S.C. 103 as being unpatentable over Ferguson (US 20110285586 A1, cited on IDS) in view of [Syrjarinne (US 20070159387 A1) or Camp (US 6075987 A) or Twitchell (US 6222483 B1)] as applied to claims 1 and 16 above, and further in view of Thomson (US 20100134352 A1).
Regarding claims 22 and 25, Ferguson does not teach wherein the safe ephemeris data comprises safe clock data, and wherein performing the comparison comprises: calculating a clock difference between clock data derived from the reference ephemeris data and the safe clock data; and determining that the clock difference exceeds a predetermined threshold.
Thomson teaches determining spoofing (abstract “detecting one or more forged satellite measurements”) by calculating a clock difference between clock data derived from reference ephemeris data and safe clock data; (abstract “The determined navigation data message may then be compared with the received navigation data message portion to thereby determine whether any of the one or more satellite measurements transmitted by the device have been forged”; para. [0034] “any portion or multiple portions of the navigation data message discussed above may be requested by the location determining system”; paras. [0029]-[0030] describing the navigation data message as comprising “satellite clock parameters”); and determining that the clock difference exceeds a predetermined threshold (a threshold is considered inherent to determining a “match” as per para. [0036]).
It would have been obvious to further modify Ferguson in view of Thomson in order to provide an additional indication of spoofed signals. This is a matter of combining prior art elements according to known methods to yield predictable results, an exemplary rationale that supports a conclusion of obviousness, see KSR Int’l Co. v. Teleflex Inc.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Marmet (US 20200371246 A1) teaches detecting spoofing (abstract “detect spoofing”) by comparing “all or part of navigation messages” (para. [0078]).
Zangvil (US 20220236425 A1) teaches GNSS navigation messages comprising clock parameters (para. [0283]).
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/CASSI J GALT/Primary Examiner, Art Unit 3648