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Paramétrages

Paramétrages

1. WO1995033188 - APPAREIL ET PROCEDE DE SPECTROSCOPIE A RESOLUTION TEMPORELLE

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

Claims

What is claimed is:
1. A method of performing time resolved measurements comprising the steps of:
propagating a light wave generated by a light source; modulating said light wave amplitude with a pseudorandom code;
transmitting said light wave to an object;
detecting a return signal from said object based on said light wave;
digitizing said return signal; and
processing said return signal so as to obtain a time resolved measurement of said return signal.

2. The method according to claim 1 wherein said step of propagating said light wave includes the step of generating said light source from a continuous wave laser.

3. The method according to claim 1 wherein said step of modulating said light wave includes digitally modulating said light wave amplitude.

4. The method according to claim 1 wherein said pseudo-random code has a fixed length and modulation time bin width.

5. The method according to claim 1 including the step of introducing a modulation start delay time before the step of transmitting said light wave wherein said step of digitizing said return signals is performed at a continuously uniform rate with respective to said modulation start delay time.

6. The method according to claim 1 wherein said step of modulating said light wave includes the step of introducing a given time delay in a plurality of code cycles used in said pseudo-random code.

7. The method according to claim 6 wherein said step of digitizing said return signal includes the step of interlacing said digitized return signal with said time delay, thereby forming a high resolution return signal.

8. The method according to claim 7 wherein said step of processing said return signal includes the step of calculating correlation values for said high resolution return signal and a reference code in arriving at said time resolved measurement.

9. The method according to claim 8 further comprising the step of deconvolving said time resolved signal for obtaining a true return signal with a high time resolution.

10. The method according to claim 1 wherein said step of modulating said light wave includes the steps of:
generating a pseudo-random number code, which provides a full depth digital modulation; and,
generating a sequence of delay time values, which introduces a high resolution time information based on a selected sequence of delay time values with respect to the start time of step of digitizing said return signal at the start of said modulation of said transmitted signal.

11. The method according to claim 6 including the step of generating a prescribed sequence based on said time delay and said plurality of code cycles.

12. The method of claim 1 further comprising the steps of:
performing a differential measurement by said light wave having a first wavelength and a second light wave having a second wavelength, each light wave being modulated by different pseudo-random modulation correlation (PRM) codes; and,
separating said return signal from any random noise during said step of correlating said return signal with corresponding reference codes.

13. The method of claim 1 wherein said step of transmitting said light wave causes said object to fluorescence and said return signal is based on the fluorescencing of said object.

14. The method of claim 1 wherein said light wave scatters and migrates upon and within said object and said return signal is said scattered and migrating light wave.

15. A spectroscopy sensor system for performing time-resolved measurements comprising:
means for propagating a series of electromagnetic signals;
means for modulating said electromagnetic signals using a pseudo-random code;
means for transmitting said series of electromagnetic signals towards an object;
means for receiving a return signal from said object based on said electromagnetic signals;

means for determining a temporal profile of said signals returned from said object;
means for deconvolving said temporal profile using a reference code auto-correlation function;
means for obtaining a true high resolution temporal profile of said signals returned from said object.

16. The system of claim 15 wherein said means for obtaining said high resolution temporal profile is responsive to means of introducing selected delay times, which are interlaced into each cycle, for obtaining said high resolution profile.

17. The system of claim 15 wherein said means for propagating said electromagnetic signal comprises a continuous wave laser.

18. The system of claim 15 wherein said electromagnetic signals causes said object to fluorescence and said return signal is based on the fluorescencing of said object.

19. The system of claim 15 wherein said electromagnetic signals scatter and migrate upon and within said object and said return signal is based on said scattered and migrating electromagnetic signals.

20. A sensor system for performing time resolved spectroscopy, the system comprising:
a laser transmitter;
a pseudo-random code modulator for modulating a light beam generated by said laser transmitter with a pseudorandom code;
a scanner for scanning said light beam across a target;

a receiver for receiving a return signal from said target scanned by said scanner;
a square law detector, coupled to said receiver, that detects the received return signal from said receiver; a preamplifier, coupled to said square law detector, that provides signal noise rejection of said received return signal;
an amplifier, coupled to said preamplifier, for amplifying said received return signal;
a filter, coupled to said amplifier, for filtering said received return signal;
a analog-to-digital converter, coupled to said amplifier and said filter, that digitizes said received return signal;
a signal accumulator, coupled to said analog-to-digital converter, for interlacing said digitized return signal to form a contiguous, high resolution data set and for integrating said data set over a set time;
a correlator, coupled to said signal accumulator, that processes said data set for correlation values between a reference modulation sequence and said high resolution data set and then deconvolves said correlation values from said data set to obtain a high resolution temporal profile based on selected states of said target.