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Paramétrages

Paramétrages

1. WO1986004435 - IDENTIFICATION DE PRECIPITATIONS PAR L'UTILISATION DE MESURES DE LA TAILLE ET DE LA VITESSE DES PARTICULES, DES COEFFICIENTS D'EXTINCTION ET DE L'HUMIDITE

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

1. A present weather observing system comprising:
means for providing a beam of radiation in the atmosphere;
means, having a field of view intersecting said beam to define a sample volume, for detecting scattered radiation from particles within said sample volume;
means for determining the size and velocity of at least one particle precipitating through said sample volume; and
means responsive to said means for determining size and velocity for identifying the type of precipitation.

2. The observing system of claim 1 in which the means-for determining size and velocity includes means for • resolving a signal due to at least one precipitating
particle from signals due to suspended particles .

3. The observing system of claim 2 in which said resolving means includes means for setting a threshold above which a precipitating particle is resolved.

4. The observing system of claim 3 in which said resolving means includes means for maintaining said
threshold above the level due to suspended particles .

5. The observing system of claim 2 in which said means for determining size and velocity includes means for
generating a peak signal value and means for generating a time-in-sample value..

6. The observing system of claim 2 in which said identifying means includes means for matching size and velocity of said precipitating particle with predetermined values of precipitation particle sizes and velocities.

7. The observing system of claim 2 in which said resolving means includes means for distinguishing a
precipitating particle signal greater than a predetermined magnitude from a precipitating particle signal less than the predetermined magnitude.

8. The observing system of claim 7 in which said greater signal is due to a particle having a size larger than said predetermined magnitude and said lesser signal is due to a particle having a size smaller than said
predetermined magnitude. .

9. The observing system of claim 7 in which said means for determining size and velocity includes:
means for generating- a peak signal value having a first peak signal generator responsive to said greater signal and a second peak signal generator responsive to said lesser signal; and
means for generating a time-in-sample value having a first time-in-sample generator responsive to said greater signal and a second time-in-sample generator responsive to said lesser signal.

10. The observing system of claim 7 in which said means for determining size and velocity includes means for indicating said resolved precipitating particle signal and means for counting said indications.

11. The observing system of claim 10 in which said identifying means includes means for matching size and velocity of said precipitating particle with first
predetermined values for precipitation sizes and velocities when an indication rate is less than a predetermined rate and with second values when the indication rate greater than a predetermined rate.

12. The observing system of claim 11 further including means for ascertaining the amount of precipitation.

13. The observing system of claim 12 in which said ascertaining means includes means for discerning the volume of said precipitating particle.

14. The observing system of claim 13 in which said ascertaining means includes means for summing the volumes of more than one precipitating particle over a known time~ period.

15. The observing system of claim 2 in which said means for providing a beam emits square-wave modulated radiation.

16. The observing system of claim 15 in which said radiation is emitted at a rate of one to four kilohertz.

17. The observing system of claim 15 in which said means for determining size and velocity includes adjusting means for synchronizing said determining means with said pulse rate.

18. The observing of claim 2 in which said means for providing a beam emits radiation having a wavelength
selected from visible and near-visible spectral regions.

19. The observing system of claim 18 in which said means for providing a beam includes a light-emitting diode.

20. The observing system of claim 2 in which said detecting means has a field of view encompassing only, the forward scattered radiation.

21. The observing system of claim 20 in which said field of view encompasses radiation scattered forward at an average angle of 30 to 55 degrees from the axis of said beam.

22. ' The observing system of claim 2 in which said detecting means includes a photoelectric element.

23. The observing system of claim 22 in which said photoelectric element is a photovoltaic cell.

24. The observing system of claim 2 in which said detecting means includes means for separating signals due to scattered radiation from signals due to ambient radiation.

25. The observing system of claim 24 in which said means for separating signals includes an optical bandpass filter.

26. The observing system of claim 2 in which said sample volume is in the range of two hundred to one thousand milliliters.

27. The observing system of claim 2 in which said resolving means includes rectifying means for inverting negative peaks of signals from said detecting means.

28. The observing system of claim 2 in which said resolving means also resolves the precipitating particle signal from signals due to signal noise created by said detecting means.

29. A present weather observing system comprising:
means for providing a modulated beam of radiation in the atmosphere;
means, having a field of view intersecting said beam to define a sample volume, for detecting scattered radiation from particles within said sample volume and having at least one photoelectric element;
means, responsive to said detecting means, for determining size and velocity of at least one particle precipitating through said sample volume, said means for determining- size and velocity including means for resolving a signal due to at least one precipitating particle from signals due to suspended particles and due to signal noise created by said detecting means; and
means for defining the atmospheric extinction coefficient.

30. The observing system of claim 29 in which said coefficient defining means includes means, responsive to said detecting means, for subtracting signals due to
scattered radiation detected when at least one precipitating particle is resolved from scattered radiation detected during the remainder of the sampling period when such a particle is not resolved.

31. The observing system of claim 30 in which said coefficient defining means includes means for averaging said scattered radiation signals and means for averaging the output of the subtracting means.

32. The observing system of claim 31 in which said coefficient defining means includes means for obtaining the total extinction coefficient from the average of the
scattered radiation signals and means for obtaining the extinction coefficient due to suspended particles from the average of the output of the subtracting means.

33. The observing system of claim 32 further including a humidity sensor for sensing relative humidity and means for identifying the type of suspended particles within the sample volume by matching the extinction coefficient due to suspended particles with predetermined values for types of suspended particles and with the relative humidity.

34. The observing system of claim 30 in which said means for defining the extinction coefficient includes means responsive to said detecting means for providing said scattered radiation signals in DC analog form.

35. A method of identifying the type of precipitation comprising:
providing a beam of radiation in. the atmosphere;
detecting scattered radiation in a sample volume of the beam;
resolving at least one precipitating particle from suspended particles;
generating a peak signal value and a
time-in-sample value for a resolved particle;
determining particle size from the peak signal value;
determining velocity from the time-in-sample value; and
matching size and velocity of the particle with predetermined values of precipitation particle sizes and velocities.

36. The method of claim 35 further including:
discerning the volume of said precipitating particle; and
summing the volumes of more than one precipitating particle over a known time period to determine the amount of precipitation.

37. The method' of claim 35 further including:
subtracting signals due to scattered radiation detected when at least one precipitating particle is
resolved from scattered radiation detected during the remainder of a sampling period when such a particle is not resolved to provide signals due to suspended particles;
averaging the scattered radiation signals;
averaging the suspended-particle signals;
obtainin'g the total extinction coefficient from the average" of the scattered radiation signals; and
obtaining the extinction coefficient due to suspended particles from the average of the
suspended-particle signals.

38. The. method of claim 37 further including sensing the relative humidity and identifying the type of suspended particle within the sample volume by matching the extinction coefficient due to suspended particles with predetermined values for types of suspended particles and with the
relative humidity.