Monday, April 9, 2018

Radar-based target determination method claims saved from Alice by improvement arguments at the PTAB

Takeaway: Viewing the claims as representing an improvement upon technology that uses synthetic aperture radar imaging to determine the position of a target at great distances, the PTAB reversed Alice rejections that had found claims to be directed to patent-ineligible subject matter.  The broadest claim was what could be called a "pure software" claim, consisting solely of "determining" steps taking place inside a computer processor.


Ex parte Benninghofen

Appeal No. 2016-002156; Application No. 13/380,397; Tech. Center 3600
Decided: Oct. 16, 2017

The application on appeal described a method for determining the geographic coordinates of pixels in synthetic-aperture radar images.  A representative claim on appeal read:

5.     A method, comprising:
        determining, by a processor of an airborne device, geographic coordinates of corresponding pixels of a target from first and second digital synthetic aperture radar (SAR) images by capturing, by the processor of the airborne device, the first and second SAR images in a form of slant range images;
        determining, by the processor of the airborne device, a recording position of the respective first and second SAR images;
        determining, by the processor of the airborne device, a distance between a corresponding resolution cell on a ground and the respective recording position of the respective first and second SAR images using coordinates of the corresponding pixels of the target in the first and second SAR images and corresponding range gates; and
        determining, by the processor of the airborne device using the determined distances and associated recording positions of the first and second SAR images, the geographic coordinates of the corresponding pixels of the target in the first and second SAR images by producing, by the processor of the airborne device, a first and second sphere for the first and second SAR images using the determined distances and associated recording positions of the first and second SAR images; and
        determining, by the processor of the airborne device, the geographic coordinates of the corresponding pixels of the target as a common intersection of the first and second spheres with the WGS84 ellipsoid.
SAR is a form of radar used to acquire high-resolution landscape data from aircraft or spacecraft using comparatively small physical antennas.  Range gates appear to refer to the distances away from the SAR antenna at which are located resolution cells on the ground that correspond to the center of the SAR slant range images.  WGS 84, the 1984 World Geodetic System standard, is the reference coordinate system used by the Global Positioning System (GPS), and its reference ellipsoid is a mathematically defined surface that approximates the geoid, i.e., the truer figure of the Earth.  Thus, in essence, the application provides a way of matching SAR-sourced image pixels to geographic coordinates.  The eight-page written description contains several of what appear to be basic Euclidean distance formulas, and is accompanied by seven drawings of basic geometric diagrams.

In a § 101 rejection, the examiner alleged the claims to be abstract since they "employ mathematical relationships/formulas to determine the geographic coordinates of the corresponding pixels of the target."  The examiner found that the claims did not supply "significantly more" under the second step of the Alice framework because they required no more than a generic computer, in the form of the recited airborne device, "to perform generic computer functions that are well-understood, routine and conventional activities previously known to the industry."

The applicants conducted several examiner interviews and filed an after-final response, arguing that "the claims recite significantly more than mere computer implementation of an abstract idea and the ordered combination of steps improves the functioning of a processor itself."  The claim 5 method, applicants asserted, "determines SAR image recording positions and distances based on the determined recording positions, and then uses this information to transform SAR images into first and second spheres, which are then used with a WGS84 ellipsoid to determine geographic coordinates of pixels in an image. Thus, the claims go beyond merely retrieving and combining data."  The applicants further posited that the sole independent claim

improves the overall functioning of a processor because it is able to determine geographic coordinates in an image in a much less processor intensive manner than other techniques. Specifically, . . . the prior art cited to reject the claims [in other art-based rejections] determines geographic coordinates using interferomic SAR (InSAR or IFSAR), which determines phase differences between of master and slave SAR images to generate an interferogram characterizing topographic information.  Obtaining the master and slave images requires the use of a diplexer because obtaining the images requires one transmission antenna and two receiving antennas, which significantly increases the required processing power. Further, the present invention avoids the additional processing required to generate the interferogram and thus improves the overall operation of the processor used for determining geographic coordinates of pixels of a target.
(Emphasis added.)  When the examiner maintained the § 101 rejection, the applicants filed a pre-appeal conference request, arguing that, under the first step of the Alice framework, their claimed method
involves capturing images in which the target is located, which is not an algorithm and is not abstract. The method also involves determining a recording position of the images, which reflects real-world geographic coordinates, and is not an algorithm and is not abstract.  The method further involves determining a distance between a resolution cell on the ground and the recording positions, which is not abstract.
The conference request also repeated the "significantly more" argument from the after-final response.  The conference panel was not persuaded.

In their appeal brief, the appellants argued, among the many unavailing arguments presented, that the data gathering steps of the claim could not be performed by the human mind.  However, they also repeated their inchoate improvement argument, asserting that the claimed method "is able to determine geographic coordinates in an image in a much less processor intensive manner, and with less error."  The appellants were also able to point to support in their specification for a new assertion that the rejected independent claim "improves upon the technical field of position determination with SAR images by reducing error in the known techniques".

Answering the argument that the conventional pre-solution steps could not be performed in the human mind, the examiner cited CyberSource Corp. v. Retail Decisions Inc., 654 F.3d 1366, 1370 (Fed. Cir. 2011), for the proposition that mere data-gathering steps cannot make an otherwise nonstatutory claim statutory.  The examiner found the processor in the airborne device not to qualify for "significantly more."  The examiner did not address the improvement arguments in the answer brief, perhaps unsurprisingly, since Enfish and McRO were yet to be decided.  The appellants filed a reply brief, but without anything in the way of new or expanded argument, so the case went to the Board, where the panel opined:
With respect to computer-enabled claimed subject matter, it is helpful to determine whether the claims at issue may readily be understood as simply adding conventional computer components to well-known business practices or not.  The question is whether the claims as a whole “focus on a specific means or method that improves the relevant technology” or [by contrast] are “directed to a result or effect that itself is the abstract idea and merely invoke generic processes and machinery.”
(Citations omitted.)  The Board noted that in Enfish, the Federal Circuit "found that the 'plain focus of the claims' there was on 'an improvement to computer functionality itself, not on economic or other tasks for which a computer is used in its ordinary capacity.'"  The Board thus held the claimed invention to be patent-eligible subject matter as "'an improvement upon technology that uses SAR image to determine the position of a target at great distances,' thus providing a specific improvement in computer capabilities".  Quoting the appellants' arguments, the Board noted that "it does not appear that [the] claims simply add conventional computer components to an otherwise known practice, or invoke computer components merely as a tool to implement an otherwise abstract idea", and reversed the § 101 rejection.

My two cents:

This post is fourth in a series discussing how improvement arguments have saved the day for appellants facing Alice rejections.  The original post predicted that such arguments will soon be on the ascendant as the weapon of choice in combating rejections alleging that claims are directed to abstract ideas, and gave a few relevant practice tips.  Cases like this one make it look easy.  Although the examiner was obstinate that the claims, which, at their broadest, were limited solely to data analysis steps, fell squarely within the abstract-idea judicial exception carved out of 35 U.S.C. § 101, the Board was easily persuaded that the claims did not tie up an abstract idea and reversed the rejection.  The Board did not, for example, require the appellants to prove with quantitative data that the claimed method reduced processor effort and resulted in less error, as asserted in their arguments.  Nor even did the Board require the appellants to provide detailed reasoning showing why such improvements were inherent to the method.  The appellants' arguments look conclusory, but they were enough here, in part, probably, because the examiner did nothing to address them, despite full opportunity (unlike in the case discussed last week, in which the arguments were fleshed out only in the reply brief).

It's difficult to make sense of the applicants' "significantly more" argument as presented in their after-final response.  It is not surprising that the examiner was not persuaded by the applicants' citing to a series of data collection and processing steps followed by a conclusory assertion that "the claims go beyond merely retrieving and combining data."  The difficulty of formulating persuasive Alice second-step arguments in claims that more or less amount to pure software is one reason for the appeal of improvement arguments, which can apply even at step one.

Because the analysis is so thin on all sides, it's difficult to pinpoint why this improvement argument won, or if it would have won if challenged by the examiner.  Likely, in absence of more detailed Supreme Court guidance, a lot of § 101 thinking is still "I know it when I see it."  The improvement argument succeeded in this case where traditional "significantly more" arguments would probably not have been persuasive, since all of the recited or implied features outside the abstract idea itself were conventional components: an SAR sensor, a computer processor.

Stay tuned as we continue to look at how improvement arguments can prevail over Alice rejections of software claims.

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