Application of Walter

• Decision Date: 27 March 1980
• Docket Number: Appeal No. 79-599.
• Citation: 618 F.2d 758
• Parties: In the Matter of the Application of William C. WALTER.
• Court: U.S. Court of Customs and Patent Appeals (CCPA)

618 F.2d 758

In the Matter of the Application of William C. WALTER.

Appeal No. 79-599.

United States Court of Customs and Patent Appeals.

March 27, 1980.

COPYRIGHT MATERIAL OMITTED

Reed C. Lawlor, Pasadena, Cal., attorney of record, for appellant, Robert C. Smith, Sylmar, Cal., of counsel.

Joseph F. Nakamura, Washington, D. C., for the Commissioner of Patents, Jere W. Sears, Washington, D. C., of counsel.

Before MARKEY, Chief Judge, and RICH, BALDWIN, MILLER and MALETZ,^* Judges.

RICH, Judge.

This appeal is from the decision of the Patent and Trademark Office (PTO) Board of Appeals (board), affirming the examiner's final rejection of claims 7-14 and 16-18 in application serial No. 303,693, filed November 6, 1972, entitled "Seismic Prospecting System." The sole ground of rejection of the claims is that they are directed to nonstatutory subject matter under 35 U.S.C. § 101. We affirm.

The Invention

Appellant's invention is used in seismic prospecting and surveying. In this field, seismic source waves are generated and transmitted downwardly into the earth. There they are deflected by subsurface formations and anomalies. The deflected waves return to the earth's surface and are detected by transducers, known as geophones, which are distributed on the surface over the area of exploration. The geophones convert the returning mechanical vibrations into electrical signals, which are then recorded on a record medium, such as magnetic tape or chart recorder, for analysis. By studying the records of the deflected waves, analysts are able to make determinations concerning the nature of the subsurface structure of the earth.

Several types of seismic source waves have been used in seismic prospecting and surveying. One type, known as impulse waves, are sharp pulses lasting 0.05 second or less and are generated by a powerful force of short duration, such as an explosion. Another type of seismic source wave, with which appellant's invention is used, are "chirp" signals. A chirp signal is a frequency-modulated continuous wave in which the frequency of vibration is varied as a function of time, usually a linear function, over a substantial period of as much as several seconds. Chirp signals are often referred to as "sweep" signals, since the frequency is swept from one value to another. Chirp signals are generated by mechanical apparatus which vibrates against the surface of the earth.

As a chirp signal travels down into the earth, it is deflected by subsurface features which lie at varying depths and at different distances from the numerous geophones which are set out on the surface. At any given instant, therefore, a single geophone receives portions of the returning chirp signal which have been deflected from different depths and locations. This composite signal is a jumble of different frequency components. Before the results of the survey can be evaluated, the jumbled signal must be broken down into its components and its individual deflected portions identified.

Appellant has invented a method, and apparatus for performing the method, of cross-correlating the returning jumbled signal with the original chirp signal which was transmitted into the earth. As a result, the returning signal is effectively unscrambled; each of the trains of waves received at each geophone station is converted to a form equivalent to the type of signal which would have been produced had an impulse-type signal been used in place of the chirp signal. Appellant's claims identify these end products as "partial product signals."

Appellant's method is performed on the record signal made from each geophone. The record signal is sampled and converted to a digital format. It is then divided into segments. Several mathematical operations are performed, including computing Fourier transforms and cross-correlation utilizing the Cooley-Tukey algorithm as modified by Bergland.¹ Appellant's claim 7 is illustrative of his invention:

7. In a method of seismic surveying in which a train of seismic source waves is transmitted downwardly into the earth and is there deflected by subsurface formations and in which corresponding trains of seismic waves deflected by such formation are received at geophone stations in a spread at the surface of the earth and wherein;

each train of received seismic waves is converted into a corresponding series of digital sample signals; and

a series of reference signals corresponding to sample of said transmitted seismic waves is developed;

the improved method of correlating said series of sample signals for each geophone station with respect to said series of reference signals that comprises

a) converting said series of sample signals into an augmented series of sample signals divided into N + 1 segments of equal length thereby forming a series of sequential segments Si of said augmented series, including an empty end segment, where i = 1 ..., N + 1;

b) forming a Fourier transform FTSi of each respective series of signals composed of pairs of successive segments Si and Si + 1 of said augmented series, each said Fourier transform being represented by a first series of transform signals,

c) forming a combined segment of each segment Cj of said reference signals and an empty segment of equal length, where j = 1, ... L, each said combined segment comprising a series of signals of double length, where L = N,

d) forming a corresponding Fourier transform FTCj of each said combined segment, each said latter Fourier transform being represented by a second series of transform signals,

e) forming the non-zero conjugate complex vector products of pairs of the respective Fourier transforms and adding them together in accordance with the following expression:

where N represents the number of segments in the series of reference signals, and

O

where M is the number of segments to be produced in the cross-correlated result, to produce a series of partial product signals FTPm where m = 1, 2 ... M representative of the Fourier transform of said series of sample signals and said series of reference signals for each said geophone station.²

The Rejection

In his final rejection, the examiner stated that the claims were directed to the mathematical procedure outlined in the specification for cross-correlating the sets of signals. He found no reason to distinguish between the method and apparatus claims, holding that distinction to be legally immaterial "Where the only mode of practicing an invention is disclosed by way of an algorithm for use in a computer program."

In affirming the rejection, the board agreed that the distinction between method and apparatus claims was of no significance because "It would be anomalous to grant apparatus claims encompassing any and every `means for' practicing the method claimed in the method claims if the latter were nonstatutory * * *." It therefore addressed both categories of claims in a single discussion.

In analyzing the claims, the board viewed the activity recited in the preambles as being directed to the gathering of data. It found that steps like a) through e) of claim 7 serve to allocate the sample signals to various locations in the computer memory in accordance with the rules built into the programs for producing the end result—"a series of partial product signals ... representative of the Fourier transform of said series of sample signals and said series of reference signals for each said geophone station," quoting from the last clause of claim 7.

The board stated that practicing the method steps had to include processing the disclosed formulas and operating the computers according to the Cooley-Tukey algorithm as modified by Bergland. After reviewing the definition of the word "algorithm" as used by the Supreme Court in § 101 cases,³ the board characterized appellant's claims as mathematical exercises giving the following three reasons (bracketed numerals ours):

1Steps a)-e), at their most fundamental level as processed in the computer, must necessarily be carried out employing the radix or radices imposed by the architecture of the computer used, binary, binary coded decimal, or the like. It would be difficult, not to say misleading, to characterize such operations as non-mathematical.

2At a secondary level, the steps referred to serve to accommodate the input data to a memory, finite in size, requiring the tailoring and configuring of the data to the particular architecture of the memory, note appellant's Figures 13-16 and attendant description, pages 123-139. We think this is a mathematical operation.

3Needless to say, the processing incident to the employment of the formulas to which we have referred must also be considered mathematical.

It is also apparent that the processing recited in these steps is directed to the solution of a problem, that of producing a series of partial product signals. Accordingly, we consider appellant's claims to be directed to the processing of an algorithm.

Next, the board addressed the question of preemption of the algorithm, holding that it would be effectively preempted by the claims. Although it recognized that the calculations could be carried out by manual effort, the board found that

* * * the total amount of calculation required for the purposes of producing a practical or useful result would be, we think, so horrendous, and the effort so tedious and time consuming, as to render that alternative (if publicly available), or others like it, to be trivial in consequence.

The board distinguished In re Johnson, 589 F.2d 1070, 200 USPQ 199 (Cust. & Pat.App.1978), on its facts. According to the board, the method claims in Johnson

* * * called for computer programming which improved a signal, i. e., reduced noise, whereas the subject matter at bar purports, as the result of solving a mathematical problem, to produce partial product signals, that is, the method produces a solution.

Appellant's Arguments

Appellant's main contention is that his claims...