Office National D'etudes Et De Recherches Aerospatiales (onera)

Office National D'etudes Et De Recherche Aerospatiales (onera)

Office National D'etudes Et De Recherche Aerospatiales

Jean G Appel

Francois M Dunand

Andre Soulage

Philippe Richard

Apparatus for processing digitized images, the apparatus being of the type comprising a matrix memory (104) of pixels (106) organized as N lines (108) by P columns (110), together with processing means (130) for determining which pixels (106) are in the excited state by reading the memory (104). The processing means (130) operate by determining and storing the address of an excited pixel (106) that occupies an extreme position in a line or a column position, by switching said pixel (106) to a non-excited state, and by reiterating these operations until none of the pixels (106) is excited.

Method and apparatus for processing digitized images

The occurrence and frequency of a periodic component embedded in a composite waveform including noise is detected by real time calculating the autocorrelation function of the waveform and deducing the frequency of the periodic component from the value of the autocorrelation function coefficients. An analog-to-digital converter periodically transforms the waveform into samples having q bits. The samples are delayed by a predetermined time interval .DELTA.t and multiples thereof, to derive 2n delayed samples, x.sub.i, x.sub.i-1 . . . x.sub.i-2n. The delayed samples are multipled to derive 2n products, such that the first n products are represented by x.sub.1 .multidot.x.sub.i-k and the second n products are represented by x.sub.1-n .multidot.x.sub.i-(n+k), where k is selectively 1 . . . n. Difference between the first and second products are obtained as (P.sub.1 -P.sub.n+1) . . . (P.sub.n-1 -P.sub.2n), where P.sub.1 =x.sub.i .multidot.x.sub.i-1, P.sub.n-1 =x.sub.i .multidot.x.sub.i-n, P.sub.+1 =x.sub.i-n .multidot.x.sub.i- n+1, P.sub.2n =x.sub.i-n .multidot.x.sub.i-2n. The differences are integrated to derive autocorrelation funtion coefficients of the input signal. In response to at least one of the coefficients exceeding a predetermined threshold, an indication that the input signal contains a periodic component is derived.

Apparatus for and method of processing signals in a composite waveform

The installation comprises a certain number of measuring stations, represed here as three in number referenced respectively 1, 2 and 3, equipped respectively with antennae I.sub.1, I.sub.2, I.sub.3, which are connected by transmission lines L.sub.1, L.sub.2 and L.sub.3 to a central data acquisition unit 4, itself connected to a real time data processing unit 5. The central unit 4 comprises receiving means, means for sorting and associating the data and means for momentary storage of the sorted and associated data.

Installation for the detection and location by interferometry, in real

Device for measuring the speed of a fluid in a tube which comprises two uasonic electro-acoustic transducers in the tube; means for energizing these transducers by first and second transmit pulse groups; means for receiving first and second receive pulse groups at the transducer output; means for measuring a first delay between the start of the first transmit pulse group and the start of the first receive pulse group and a second delay between the start of the second transmit pulse group and the start of the second receive pulse group; and means for measuring a third delay between the starts of the first and second receive pulse groups. The flow rate is proportional to the quotient of the third delay by the product of the first and second delays. These delays comprise an integer delay part which is measured by clock pulses counting and fractional delay parts which are measured by constant current integrators.

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Le Plessis Robinson, France

Jean G Appel