Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
  • G01S13/88—Radar or analogous systems specially adapted for specific applications
  • G01S13/95—Radar or analogous systems specially adapted for specific applications for meteorological use
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
  • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
  • G01S13/06—Systems determining position data of a target
  • G01S13/08—Systems for measuring distance only
  • G01S13/10—Systems for measuring distance only using transmission of interrupted, pulse modulated waves
  • G01S13/22—Systems for measuring distance only using transmission of interrupted, pulse modulated waves using irregular pulse repetition frequency
  • G01S13/227—Systems for measuring distance only using transmission of interrupted, pulse modulated waves using irregular pulse repetition frequency with repetitive trains of uniform pulse sequences, each sequence having a different pulse repetition frequency
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
  • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
  • G01S13/50—Systems of measurement based on relative movement of target
  • G01S13/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
  • G01S13/581—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of interrupted pulse modulated waves and based upon the Doppler effect resulting from movement of targets
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
  • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
  • G01S13/50—Systems of measurement based on relative movement of target
  • G01S13/52—Discriminating between fixed and moving objects or between objects moving at different speeds
  • G01S13/522—Discriminating between fixed and moving objects or between objects moving at different speeds using transmissions of interrupted pulse modulated waves
  • G01S13/524—Discriminating between fixed and moving objects or between objects moving at different speeds using transmissions of interrupted pulse modulated waves based upon the phase or frequency shift resulting from movement of objects, with reference to the transmitted signals, e.g. coherent MTi
  • G01S13/53—Discriminating between fixed and moving objects or between objects moving at different speeds using transmissions of interrupted pulse modulated waves based upon the phase or frequency shift resulting from movement of objects, with reference to the transmitted signals, e.g. coherent MTi performing filtering on a single spectral line and associated with one or more range gates with a phase detector or a frequency mixer to extract the Doppler information, e.g. pulse Doppler radar
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
  • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
  • G01S13/50—Systems of measurement based on relative movement of target
  • G01S13/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
  • G01S13/581—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of interrupted pulse modulated waves and based upon the Doppler effect resulting from movement of targets
  • G01S13/582—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of interrupted pulse modulated waves and based upon the Doppler effect resulting from movement of targets adapted for simultaneous range and velocity measurements
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
  • G01S13/88—Radar or analogous systems specially adapted for specific applications
  • G01S13/95—Radar or analogous systems specially adapted for specific applications for meteorological use
  • G01S13/951—Radar or analogous systems specially adapted for specific applications for meteorological use ground based
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
  • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
  • G01S7/28—Details of pulse systems
  • G01S7/285—Receivers
  • G01S7/292—Extracting wanted echo-signals
  • G01S7/2923—Extracting wanted echo-signals based on data belonging to a number of consecutive radar periods
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
  • Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Definitions

• the present invention relates to "a method of measuring the air velocity in a region of the atmosphere.
• the radar transmits sinusoidal wave trains or pulses which are returned to the radar by particles suspended in the air; if the air has a movement causing the particles to move away from or towards the radar, the pulses returned to the radar have a phase shift with respect to the pulses emitted, an offset which makes it possible to calculate the radial velocity of the particles relative to the radar and therefore the speed of the air that carries them.
• the speed can thus be determined without ambiguity if the real speed of the particles is within a so-called Nyquist interval depending on the rate of emission of the pulses (also called emission frequency).
• the calculated velocity is equal to the actual velocity modulo the width of the Nyquist interval.
• drawbacks in particular a strong solicitation of the transmitter, a significant consumption of the latter and a reduction in the range of the radar.
• a method for measuring the air velocity in a Doppler zone of the atmosphere by means of a radar comprising the steps of:
• each pulse is emitted at a rate different from that of subsequent pulses.
• the Nyquist interval is obtained by combining the three emission rates so that the Nyquist interval is relatively wide. The pulses at the three emission rates are emitted successively to the same zone of the atmosphere, which limits the imprecision of the process.
• the calculation of the velocity V of the air comprises the phases of:
• the method comprises a step of determining the rates
• V neq ppcm (p, r) * V n i
• This mode of determination is relatively simple, reliable and fast.
• the method comprises the step to assign to the speeds V 1 ', V 2 ' and V 3 ', before their use in the calculations, a noise corresponding to the noise specific to the radar and to the usual atmospheric conditions in the measuring zone and the step of folding the speeds V 1 ', V 2 ' and V 3 'and noisy in the intervals [-Vm, Vm] / [-V n2 , V 112 ] and [-V n3 , V n3 ] to obtain the speeds V 1 ', V 2 'and V 3 ' used later in the calculations.
• FIG. 1 is a block diagram illustrating the general course of the process of the invention
• FIG. 2 is a block diagram illustrating the progress of the frequency determination step according to the invention
• FIG. 3 is a diagram illustrating the emission of pulses over time.
• the method according to the invention is implemented by means of a Doppler radar capable of emitting pulses of pulses by changing the transmission rate between each pulse. .
• the method of the invention starts with the step of emitting gusts of three pulses 1, 2, 3 at different rates F 1 , F 2 , F 3 (the duration t1 separating the pulses 1 and 2 is different from the duration t2 separating the pulses 2 and 3 and the duration t3 separating the pulse 3 from a burst of the pulse 1 of the following burst is also different from the times t1 and t2, see Figure 3).
• step 40 for determining the velocities V 1 , V 2 , V 3 of the air from the pulses received in return from the pulses 1, 2, 3 of each burst.
• the speed V of the air is then calculated from the speeds V 1 , V 2 , V 3 determined for the pulses received in return for each burst (step 50).
• step 60 the average quadratic differences obtained for all the values of k are compared with each other and the speed V te st corresponding to the smallest mean square deviation is selected as the speed V of the air (step 60).
• the step 10 for determining the rates Fi, F 2 , F 3 is detailed in FIG. 2 and begins with a phase 11 for determining pairs of parameter ratios p / q and r / s which will be used to define the rates F 2 , F 3 according to Fi.
• constraints are imposed in the choice of the parameters p, q, r, s:
• q and s are greater than p and r respectively, p / q is greater than r / s,
• r is greater than s / 2.
• the parameters p and r are advantageously greater than q / 2 and s / 2 respectively, to prevent the rates F 2 and F 3 are much lower than the rate F 1 , which may cause wear magnetron radar.
• the parameter q is preferably equal to p + 1.
• the step of determining the pulse emission rates continues with a phase 12 during which the selection of a first rate F 1 depends on the technical characteristics of the radar and the calculation of a Nyquist velocity V nl. corresponding.
• a noise corresponding to the noise specific to the radar and the usual atmospheric conditions in the measurement zone is assigned to the speed V 1 'and the velocity V 1 ' thus noisy is folded as before in the range [- Vm / V nl ] to obtain the speed V 1 'used later in the calculations.
• the noise added to the speed V 1 1 is a Gaussian distribution noise of zero average and standard deviation parameterizable so that this noise corresponds to that encountered under conditions of use.
• the step of determining the pulse transmission rates is completed by comparing the test speeds V obtained for all the couples and the speed V to select the best torque.
• the frequency determination method can be carried out for several noise levels in order to evaluate the relevance of the selected pairs with respect to the noise levels encountered.

Landscapes

• Engineering & Computer Science (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Physics & Mathematics (AREA)
• Computer Networks & Wireless Communication (AREA)
• General Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Radar Systems Or Details Thereof (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=35774618

Family Applications (1)

Country Status (4)

Families Citing this family (6)

Family Cites Families (13)

• 2005
  • 2005-06-02 FR FR0505607A patent/FR2886737B1/fr not_active Expired - Fee Related
• 2006
  • 2006-05-30 EP EP06755534A patent/EP1886166A1/de not_active Withdrawn
  • 2006-05-30 US US11/921,242 patent/US7579977B2/en not_active Expired - Fee Related
  • 2006-05-30 WO PCT/FR2006/001220 patent/WO2006129006A1/fr active Application Filing

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events