DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment/Arguments
The 12.29.2025 Amendments are entered. No claims were amended, canceled, or newly added. Claims 1-20 remain pending.
Further, Applicant’s arguments made in the 12.29.2025 remarks have been fully considered but are found unconvincing for the reasons below.
The §103 Rejections
Applicant argues on p. 6 of the Remarks that Laine does not teach “estimating, by a line of sight estimation module, an apparent bearing direction to each star in at least some of the plurality of star pairs” because [0051] of Laine only teaches estimating angles between the star pairs.
This argument is unconvincing because Laine teaches at [0003]: “A star tracker is an optical device that measures angles to one or more stars or other sufficiently bright celestial objects . . . as viewed from a vehicle.” As noted in [0048] of Laine, the sections cited as at least implicitly teaching estimating an apparent bearing angle belong to a description of the star tracker. One of ordinary skill in the art would have recognized that the angles to one or more stars would have been measured, taken broadly as estimating apparent bearing angles.
Even if Laine did not implicitly suggest measuring angles to the stars, the Broadest Reasonable Interpretation (BRI) of “apparent bearing direction to each star” includes a bearing direction to each star formed by the angle between the two stars in the star pairs. The limitation may be interpreted broadly because the apparent bearing direction is not disclosed as contributing to any calculation or function of the device.
In the interest of compact prosecution, the examiner notes that further description of the relationship between the apparent bearing direction to each of the stars and the calculation of the inter-star angle appears to narrow the claim enough to overcome the art of record. See for example p. 5 of the present specification, where it is disclosed: “An instantaneous spacecraft velocity may then be estimated based, at least in part, on the apparent inter-star angles corresponding to apparent bearing directions and based . . ..” Here, the specification suggests that the inter-star angles are somehow related to the bearing directions. Laine does not appear to expressly teach that inter-star angles are related to the bearing direction.
Applicant further contends on p. 6 that Laine does not teach “determining . . . a respective apparent inter-star angle for each star pair of the at least some star pairs . . ..” However, beyond merely alleging this deficiency, Applicant does not further explain why the cited portions of Laine do not teach the limitation. Therefore, this argument is also unconvincing.
On pp. 6-7, Applicant also alleges that Laine, by only teaching using star trackers to estimate position or attitude, it would not have been obvious to combine that reference with Christian. Applicant claims that hindsight bias may have played a part in the combination.
This argument is also unconvincing. Laine is not relied upon to teach estimating a velocity using inter-star angle, instead, Christian is. Laine is merely relied upon to teach another method by which inter-star angle may be measured- using an image containing multiple stars rather than multiple cameras each capturing one star. Furthermore, one of ordinary skill in the art at the time of filing would have recognized the benefits of simplifying the star tracking system and potentially reducing its weight by reducing the number of parts.
Therefore, the prior art rejections stand.
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 1-5, 9, 11-14, and 17-20 are rejected under 35 U.S.C. 103 as being unpatentable over StarNav: Autonomous Optical Navigation of a Spacecraft by the Relativistic Perturbation of Starlight by John A Christian (“Christian,” see the attached IDS), and further in view of US 20190033421 A1 to Laine, Juha-Pekka et al.(“Laine”).
Regarding claim 1, Christian teaches a method for determining a spacecraft instantaneous velocity using starlight (Christian §5: “Instantaneous Estimation of Velocity from Simultaneous Star Sightings”), the method comprising:
estimating, by a velocity estimation module, a spacecraft velocity to within a total velocity error based, at least in part, on the apparent inter-star angles (Christian §5.3: The section is dedicated to estimating instantaneous velocity based on sensed inter-star angles. APOSITA would have understood that, taken in the combination with Laine below, the inter-star angles measured therein would have been used in the velocity estimation above.).
While Christian teaches estimating inter-stair angles for pairs of stars using a camera system where one camera is used to find the bearing of one star, it does not appear to expressly teach determining, by a star pairing module, a plurality of star pairs in a selected star field image, the selected star field image comprising a plurality of star images;
estimating, by a line of sight estimation module, an apparent bearing direction to each star in at least some of the plurality of star pairs;
determining, by the line of sight estimation module, a respective apparent inter-star angle for each star pair of the least some star pairs.
However, Laine teaches determining, by a star pairing module, a plurality of star pairs in a selected star field image (Laine [0052], FIG. 17: “Angle data from the image sensors 814 and 816 may include angles, taking into account focal length of the lens 802 or 804, between pairs of the celestial objects 804-810, or their centroids, that are projected onto the image sensors 814 and 816.” The system of Laine teaches determining a plurality of star pairs by teaching the celestial bodies are paired off for angular measurement. The stars are imaged by the star camera of FIG. 17, which is taught to comprise three orthogonal cameras of the various embodiments of Laine.), the selected star field image comprising a plurality of star images (Laine [0048], FIG.7: Pixelated image sensor 716 images stars 708-714. Projection onto the pixelated image sensor taken as the star field image, celestial objects taken as star images.);
estimating, by a line of sight estimation module, an apparent bearing direction to each star in at least some of the plurality of star pairs (Laine [0052]: The bearing direction to each star is at least implicitly estimated by merit of the angle between pairs of celestial objects being measured.);
determining, by the line of sight estimation module, a respective apparent inter-star angle for each star pair of the least some star pairs (Laine [0052]: “Angle data from the image sensors 814 and 816 may include angles, taking into account focal length of the lens 802 or 804, between pairs of the celestial objects 804-810, or their centroids, that are projected onto the image sensors 814 and 816.”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the present invention to have combined the system for measuring spacecraft velocity using inter-star angles between pairs of stars taught by Christian with the system that calculates inter-star angles of stars in an image taught by Laine. Doing so would have simplified and reduced the weight of the star tracking system by using fixed wide angle cameras instead of the pointable cameras requiring vibration isolation and dampening taught in Laine.
Regarding claim 2, the above combination of Christian and Laine further teaches the method of claim 1, further comprising capturing, by an optical sensor, the selected star field image (Laine [0052]: “The data from the pixelated image sensors 814 and 816 may be compressed or uncompressed. The image data may include pixel value (brightness) data, or binary data simply indicating whether a given pixel receives more than a predetermined threshold amount of light, i.e., with respect to pixels on which images 826-836 of the celestial objects 806-810 are projected.” Understood that ).
This combination does not appear to expressly teach the optical sensor comprising at least one wide field of view (FOV) camera.
However, Laine further teaches another embodiment wherein the optical sensor comprising at least one wide field of view (FOV) camera (Laine FIG. 14, [0063], [0074]: “Some embodiments of monocentric lens slices have fields of view on the order of about 180°.", “Each star camera 1702-1706 may be constructed . . . such as with respect to FIGS. 7-14.” Understood that the same processing taught with respect to the lens slice of FIG. 8 applies to the other lens slices, including that of FIG. 14, see also [0064].).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the present invention to have combined the system that estimates spacecraft velocity based on inter-star angle of star pairs measured by an optical sensor taught by the above combination of Christian and the one embodiment of Laine with the camera with 180-degree field of view taught by the other embodiment of Laine. Doing so would have improved the field of view of the sensor, allowing for more potential star pairs to be identified and used for navigation, thus improving the navigational reliability and accuracy of the system.
Regarding claim 3, the above combination of Christian and Laine further teaches the method of claim 1, wherein the determining the plurality of star pairs in the selected star field image comprises forming star pairs with relatively large inter-star angles (Christian §5.2, Fig. 11: “ For each combination of 𝜃𝑖𝑗 and 𝜎. . . the results are shown in Figure 11. The best performance is achieved when 𝜃𝑖𝑗=90 deg” 90 deg broadly interpreted as a relatively large inter-star angle, as the claim does not specify the quantity the angle is large as relative to. Furthermore, Christian teaches forming star pairs with angles of up to 180 degrees.).
Regarding claim 4, the above combination of Christian and Laine further teaches the method of claim 1, wherein the estimating the apparent bearing direction comprises centroiding (Laine [0052]: “Angle data from the image sensors 814 and 816 may include angles, taking into account focal length of the lens 802 or 804, between pairs of the celestial objects 804-810, or their centroids, that are projected onto the image sensors 814 and 816.” Finding the centroid of the star for the angle measurement taken as centroiding.).
Regarding claim 5, the above combination of Christian and Laine further teaches the method of claim 1, wherein each apparent inter-star angle is in the range of 60° to 120° (Christian §5.2, Fig. 11: “When measuring the absolute stellar aberration, a solution for 𝐯 is possible with two or more star measurements. Therefore consider two stars with an inter-star angle of 𝜃𝑖𝑗 that varies from 0 to 180 deg.” See MPEP 2144.05: “In the case where the claimed ranges ‘overlap or lie inside ranges disclosed by the prior art’ a prima facie case of obviousness exists.” Here, the claimed range lies within the 0-180 degree range of the prior art. Thus, Christian teaches a case where each inter-star angle is in the claimed range.).
Regarding claim 9, the above combination of Christian and Laine further teaches the method of claim 1, wherein determining the plurality of star pairs is configured to achieve at least some associated inter-star angles in a range of 60° to 120° (Christian §5.2, Fig. 11: “When measuring the absolute stellar aberration, a solution for 𝐯 is possible with two or more star measurements. Therefore consider two stars with an inter-star angle of 𝜃𝑖𝑗 that varies from 0 to 180 deg.” The Examiner points to MPEP 2144.05: “In the case where the claimed ranges ‘overlap or lie inside ranges disclosed by the prior art’ a prima facie case of obviousness exists.” Here, the claimed range lies within the 0-180 degree range of the prior art. Thus, Christian teaches a case where the technique is at least configured to capture some inter-star angles in the claimed range.).
Claim 11 is rejected over similar reasons to claim 1 as relates to the method of claim 1, applied to a system comprising a plurality of modules (Christian FIG. 11: APOSITA would have understood that the method of claim 1 and its dependents would have been implemented as software modules on the data processing unit shown connected to the star tracker of Christian.).
Claim 12 is rejected over similar reasons to claim 2, applied to the system of claim 11.
Regarding claim 13, the above combination of Christian and Laine teaches the system of claim 12.
This combination does not appear to expressly teach wherein the optical sensor comprises three wide FOV cameras, arranged orthogonally to each other.
However, a third mentioned embodiment of Laine teaches wherein the optical sensor comprises three wide FOV cameras, arranged orthogonally to each other (Laine [0074]: “Optical axes 1708, 1710 and 1712 of the three star cameras 1702-1706 may be mutually orthogonally, or otherwise differently, oriented. Each star camera 1702-1706 may be constructed as described herein, such as with respect to FIGS. 7-14.” The Examiner notes that the star camera may have up to a 180 degree field of view, see [0063].).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the present invention to have combined the system for estimating spacecraft velocity using wide field of view cameras taught by the above combination of Christian and Laine with the navigation system comprising three orthogonal cameras that could be wide field of view cameras taught by the third mentioned embodiment of Laine. Doing so would have provided the system with the ability to estimate its position, attitude, or orientation as taught in [0077] of Laine.
Regarding claim 14, the above combination of Christian and Laine further teaches the system of claim 12, wherein each wide FOV camera has a field of view of at least 40 degrees (Laine FIG. 14, [0063], [0074]: “Some embodiments of monocentric lens slices have fields of view on the order of about 180°.", “Each star camera 1702-1706 may be constructed . . . such as with respect to FIGS. 7-14.”).
Claim 17 is rejected over similar reasons to claim 4, applied to the system of claim 11.
Claim 18 is rejected over similar reasons to claim 3, applied to the system of claim 11.
Regarding claim 19, the above combination of Christian and Laine further teaches the system of claim 12, wherein a bearing error is less than or equal to 1/10 of an instantaneous field of view of each wide FOV camera (Christian §5.3: “Obtaining an instantaneous velocity fix using inter-star angle measurements with errors below 1 mas requires a second order expansion in 𝜷. . . . Assuming a bearing error of 𝜎𝜙𝑖=0.1 mas . . . Understood that Christian teaches the velocity fix working with a bearing error of 0.1 mas, much lower than 1/10 of the 180-degree field of view in the camera taught by Laine.).
Regarding claim 20, the above combination of Christian and Laine further teaches the method according to claim 1.
While teaching a data processing unit configured to perform the method steps of claim 1, this combination does not appear to expressly teach a computer readable storage device having stored thereon instructions that when executed by one or more processors result in the following operations comprising the method according to claim 1.
However, Laine further teaches that the processing performed onboard the star tracker comprises a computer readable storage device having stored thereon instructions that when executed by one or more processors result in the following operations comprising the method according to claim 1. (Laine [0084]-[0085]: APOSITA would have understood that in this combination the method of claim 1 would have been performed on the computer parts of Laine.).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the present invention to have implemented the data processing unit and star camera system taught by the above combination of Christian and Laine on the computer readable storage device storing instructions executable on the processor taught by Laine. Doing so would have allowed the data processing to be implemented on widely available computer parts, making it cheaper and easier to produce.
Claims 6 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over StarNav: Autonomous Optical Navigation of a Spacecraft by the Relativistic Perturbation of Starlight by John A Christian (“Christian,” see the attached IDS), in view of US 20190033421 A1 to Laine, Juha-Pekka et al.(“Laine”), and further in view of US 5465212 A to Fowler, Donald et al. (“Fowler”)
Regarding claim 6, the above combination of Christian and Laine teaches the method of claim 1.
While teaching estimating a total velocity error, this combination does not appear to expressly teach wherein the total velocity error is less than or equal to a target total velocity error maximum.
However, Fowler teaches a system in which a velocity error signal must be below a threshold magnitude in order for a velocity hold condition to be achieved at 17:52-56.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the present invention to have ensured that the velocity estimated by the system of the above combination of Christian and Laine was below a threshold error magnitude as taught by Fowler. Doing so would have ensured accuracy in the velocity estimation. The improved accuracy would have further improved the navigational capabilities of the spacecraft.
Claim 15 is rejected over similar reasons to claim 6, applied to the system of claim 11.
Claims 7 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over StarNav: Autonomous Optical Navigation of a Spacecraft by the Relativistic Perturbation of Starlight by John A Christian (“Christian,” see the attached IDS), in view of US 20190033421 A1 to Laine, Juha-Pekka et al.(“Laine”), and further in view of US 20140340522 A1 to Dawson, Robin et al. (“Dawson”).
Regarding claim 7, the above combination of Christian and Laine teaches the method of claim.
This combination does not appear to expressly teach the method further comprising filtering, by a StarNAV module, the star field image based, at least in part, on at least one of vibration and/or angular motion information received from the spacecraft, the filtering configured to reduce or eliminate an effect of the vibration and/or angular motion.
However, Dawson teaches the method further comprising filtering, by a StarNAV module (APOSITA would have understood that in this combination, the processing of Dawson would have been performed onboard the data processing unit taught by Christian in FIG. 4.), the star field image based, at least in part, on at least one of vibration and/or angular motion information received from the spacecraft (Dawson [0115]: “ . . . vibration of the camera may be measured using two orthogonally oriented rate sensors . . . ” APOSITA would have understood that in the above combination, the vibration sensor would have measured the vibration of the camera of Laine, attached to the spacecraft of Christian taught in §4.1.3.), the filtering configured to reduce or eliminate an effect of the vibration and/or angular motion (Dawson [0115]: “one or more of the captured images may be analyzed based on the vibration. For example, position of one or more space objects in the image(s) may be adjusted to compensate for the vibration.”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the present invention to have combined the method of obtaining spacecraft velocity using optical image sensors attached to a spacecraft taught by the above combination of Christian and Laine with the step of measuring and filtering vibration from the star field image taught by Dawson. Doing so would have improved the accuracy of bearing estimations by removing sensor noise from the image, improving the accuracy of the images taken by the camera.
Claim 16 is rejected over similar reasons to claim 7, applied to the system of claim 11.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over StarNav: Autonomous Optical Navigation of a Spacecraft by the Relativistic Perturbation of Starlight by John A Christian (“Christian,” see the attached IDS), further in view of US 20190033421 A1 to Laine, Juha-Pekka et al.(“Laine”), and further in light of An enhanced Cramer-Rao bound weight method for attitude accuracy improvement of a star tracker by Zhang, Jun, et al. (“Zhang,” see attached 892 form for details).
Regarding claim 8, the above combination of Christian and Laine further teaches the method of claim 2, wherein a bearing error is less than or equal to 1/10 of an instantaneous field of view of the camera (Christian §5.3: “Obtaining an instantaneous velocity fix using inter-star angle measurements with errors below 1 mas requires a second order expansion in 𝜷. . . . Assuming a bearing error of 𝜎𝜙𝑖=0.1 mas . . . Understood that Christian teaches the velocity fix working with a bearing error of 0.1 mas, much lower than 1/10 of the 180-degree field of view in the camera taught by Laine.).
This combination does not appear to expressly teach the bearing error to the star is related to a camera signal to noise ratio (SNR) .
However, Zhang teaches that in centroiding algorithms used to estimate bearings to stars like those taught in Christian and Laine, the error in the position estimated is related to a camera signal to noise ratio (Zhang §I, ¶2: “ . . . the star position error is in inverse proportion to the signal to noise ratio (S/N) . . . ”).
In light of Zhang, one of ordinary skill in the art would have understood before the effective filing date of the present invention that the bearing error to the star taught by Christian would have been related to a signal to noise ratio.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over StarNav: Autonomous Optical Navigation of a Spacecraft by the Relativistic Perturbation of Starlight by John A Christian (“Christian,” see the attached IDS), further in view of US 20190033421 A1 to Laine, Juha-Pekka et al.(“Laine”), further in light of The Hipparcos Catalogue Contents by M.A.C. Perryman (“Perryman,” see attached 892 form for details).
Regarding claim 10, the above combination of Christian and Laine teaches the method of claim 1.
While Christian teaches use of the Hipparcos star catalog for the velocity measurement in §3.1.1, this combination does not appear to expressly teach wherein a star brightness cutoff magnitude is less than or equal to 14.
However, the Examiner introduces Perryman, who teaches that a star brightness cutoff magnitude of Hipparcos is less than or equal to 14 (Perryman Table 1: Limiting magnitude of Hipparcos, broadly interpreted as the cutoff magnitude, is taught by Perryman to be 12.9.).
In light of Perryman, one of ordinary skill in the art would have understood before the effective filing date of the present invention that by teaching use of the Hipparcos catalog, Christian teaches a cutoff magnitude of less than or equal to 14.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Quine, Brendan. US 5935195 A. Autonomous Star Identification.
Tsao, Tung Ching et al.. US 20140236401 A1. Star Tracker Rate Estimation With Kalman Filter Enhancement.
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to HENRY RICHARD HINTON whose telephone number is (703)756-1051. The examiner can normally be reached Monday-Friday 7:30-4:30.
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/HENRY R HINTON/ Examiner, Art Unit 3665
/HUNTER B LONSBERRY/ Supervisory Patent Examiner, Art Unit 3665