Background technology
Chlorophyll concentration is an important indicator of reaction marine phytoplankton density, through keeping watch on red tide and water quality environment situation to the measurement of chlorophyll concentration in the water.In addition, the content of chlorophyll concentration can also be as the important evidence of estimation primary productivity of marine ecosystem.
The measurement of seawater chlorophyll concentration mainly contains spot sampling laboratory measurement, scene and walks aerial survey amount and large tracts of land remote sensing survey continuously.
Shortcomings such as the spot sampling measurement has the sampling difficulty, real-time is poor, the cycle is long.
The aerial survey amount is walked at the scene continuously and the large tracts of land remote sensing survey can be measured in real time; Wherein, the scene is walked the aerial survey amount continuously and is utilized ship towing probe to realize measuring, and this metering system needs that the optical fiber that head is equipped with probe is stretched into marine bottom and measures; Though can probe be stretched into different depth; Make the chlorophyll Vertical Profile, but transmit signal, make troubles to measurement owing to rely on optical fiber; Though and the large tracts of land remote sensing survey can be realized fast, high precision, large tracts of land Measuring Oceanic top layer chlorophyll concentration, the chlorophyll measurement of vertical direction different depth had certain limitation.
At present; Laser inductive fluorescence method is obtaining application aspect the water body chlorophyll concentration measurement; This method is to utilize the laser radiation water body, excites chlorophyll molecular emission fluorescence signal in the water body, behind the reception fluorescence signal it is analyzed the concentration that draws water body chlorophyll.
Summary of the invention
For overcoming the deficiency of prior art, the object of the invention is to provide a kind of telemetry system of seawater chlorophyll concentration, and it can not only solve seawater chlorophyll concentration distribution problem in vertical direction, the characteristics that have simultaneously easily and fast, measure in real time.
The telemetry system of a kind of seawater chlorophyll vertical distribution concentration that the present invention proposes; Comprise LASER Light Source 1, modulator 2, transmitter-telescope 3, receiving telescope 4, wave filter 5, photoelectric commutator 6 and data handling system 7; The light-emitting window of LASER Light Source 1 is aimed at the light inlet of modulator 2, and the light-emitting window of modulator 2 is aimed at the light inlet of transmitter-telescope 3, and the light-emitting window of transmitter-telescope 3 is aimed at the light inlet of receiving telescope 4; Receiving telescope 4 connects wave filter 5; Wave filter 5 connects photoelectric commutator 6, and photoelectric commutator 6 converts the light signal of wave filter 5 outputs into electric signal, and photoelectric commutator 6 connects data handling system; Wherein:
Said transmitter-telescope 3 is made up of with fixed convex lens 9 removable convex lens 8; The light-emitting window of removable convex lens 8 is aimed at the light inlet of convex lens 9; The optical axis of removable convex lens 8 and fixed convex lens 9 is placed on the same straight line, and removable convex lens 8 are fixed along this rectilinear motion;
Said receiving telescope 4 is made up of with loop concave mirror 11 a small-sized concave mirror 10; Loop concave mirror 11 is installed towards seawater surface; Small-sized concave mirror 10 is installed towards loop concave mirror 11, and the distance that small-sized concave mirror 10 and loop concave mirror are 11 is both focal length sums.
Among the present invention, described LASER Light Source 1 adopts pulsed laser.
Among the present invention, described modulator 2 carries out bandwidth control with incident laser.
Among the present invention, described transmitter-
telescope 3 is made up of with fixed
convex lens 9 removable convex lens 8.The optical axis of
removable convex lens 8 and fixed
convex lens 9 is placed on the same straight line, and
removable convex lens 8 are along this rectilinear motion, thereby changes the distance between
removable convex lens 8 and the fixed convex lens 9.Can know by the convex lens image-forming principle:
; Wherein,
is object distance;
is image distance, and
is the focal length of convex lens.The removable convex lens post-concentration of parallel beam process is on its focus, and directive fixed convex lens, assembles once more behind the light process fixed convex lens.Can know by the convex lens image-forming principle; The distance of removable concave lens focus and fixed convex lens center point is object distance
; Fixed convex lens center point is image distance
with the distance of final light convergent point; Because the inverse of object distance and the sum reciprocal of image distance equal the inverse of focal length; Therefore transmitter-telescope can be through regulating the position of removable convex lens; Promptly through changing the distance between removable convex lens and the fixed convex lens; Thereby change object distance
, and then change the convergent point of fixed convex lens emergent ray.
Among the present invention, described receiving telescope 4 is made up of with loop concave mirror 11 a small-sized concave mirror 10.Loop concave mirror 11 is installed towards seawater surface; The fluorescence signal of reflected back is assembled; Another small-sized concave mirror 10 is installed towards loop concave mirror 11; The distance that small-sized concave mirror 10 and loop concave mirror are 11 is both focal length sums, makes the fluorescence signal of convergence can become directional light through small-sized concave mirror radiation, and directional light sees through the circular hole outgoing at loop concave mirror center.
Among the present invention, described wave filter 5 adopts BPF., removes and receives the hydrone Raman scattering signal except the chlorophyll molecule fluorescence signal and other algae or organism excited fluorescent signal in the light, makes output light wavelength near 685nm.
Among the present invention, said data handling system 7 is mainly used in calculates and regulates removable convex lens position, analysis of fluorescence reflected signal.Before Laser emission, data handling system calculates the distance between removable convex lens and fixed convex lens according to specifying the incident degree of depth, and sends to instruct and make removable convex lens move to assigned address.When LASER Light Source gave off laser beam, data handling system picked up counting, and according to the time of specifying this degree of depth fluorescence signal of incident depth calculation to return.During to this time, data handling system is isolated the strongest fluorescence signal, and fluorescence signal spectrum is analyzed, and according to the linear relationship of fluorescence spectrum peak height and chlorophyll concentration, draws the concentration that seawater is specified the chlorophyll molecule at incident degree of depth place.
Technique effect of the present invention is following: can realize the quick real-time measurement; Can be through the relative position between removable convex lens and the fixed convex lens in the adjusting transmitter-telescope; Change the convergent point position of transmitter-telescope shoot laser, thereby obtain on the vertical direction in the transmitter-telescope range relation between the degree of depth and chlorophyll concentration arbitrarily.
Description of drawings
Fig. 1 is a principle of work synoptic diagram of the present invention.
Fig. 2 is the receiving telescope schematic diagram.
Label among the figure: the 1st, LASER Light Source, the 2nd, modulator, the 3rd, transmitter-telescope, the 4th, receiving telescope, the 5th, wave filter, the 6th, photoelectric commutator, the 7th, data handling system, the 8th, removable convex lens, the 9th, fixed convex lens, 10 small-sized concave mirrors, 11 loop concave mirrors.
Embodiment
Combine accompanying drawing to further specify the present invention through embodiment below.
Embodiment 1:
Like Fig. 1, data handling system 7 draws the distance between the removable convex lens 8 and fixed convex lens 9 in the transmitter-telescope 3 according to specified incident depth calculation, and regulates removable convex lens 8 to assigned address.LASER Light Source 1 sends the laser that wavelength is 532nm, carries out the bandwidth modulation through modulator 2, and collimated laser beam is injected the sea through transmitter-telescope 3.
Laser beam is being set the convergence of incident degree of depth place; Excite chlorophyll in the seawater to send the fluorescence signal of 685nm; Receiving telescope 4 is assembled the fluorescence signal that fires back; Through wave filter 5 filtering, remove and receive the hydrone Raman scattering signal except the chlorophyll molecule fluorescence signal and other algae or organism excited fluorescent signal in the light, then; Wavelength is that the chlorophyll fluorescence signal of 685nm converts electric signal into through photoelectric commutator 6, gets into data handling system and carries out data processing.
Data handling system 7 picks up counting when LASER Light Source 1 gives off laser beam; And calculate the time that the incident degree of depth excited fluorescent signal that sets returns; In the corresponding time, data handling system 7 is isolated the strongest fluorescence signal, and the spectrum of fluorescence signal is analyzed; According to the linear relationship of fluorescence spectrum peak height and chlorophyll concentration, draw the concentration that seawater is specified the chlorophyll molecule at incident degree of depth place.
The principle of work of transmitter-telescope 3:
Like Fig. 2, transmitter-telescope 3 is made up of with fixed convex lens 9 removable convex lens 8.
The focal length of
removable convex lens 8 is
; Collimated laser beam is focused on its focus through removable
convex lens 8, and the distance that the focus of removable
convex lens 8 and fixed convex lens are 9 is
.
The focal length of fixed
convex lens 9 is
, and laser passes through fixed
convex lens 9 post-concentrations at a distance any of fixed distance
convex lens 9
.Therefore the distance of ignoring fixed convex lens and seawater face, the value of
is the degree of depth of specified laser incident seawater here.
Substitution convex lens imaging formula can be known
; Because
is a definite value; Therefore;
Data handling system 7 can calculate the distance between
removable convex lens 8 and the fixed
convex lens 9 according to the requirement of the incident degree of depth.Data handling system provides instruction, makes that the distance adjustment between
removable convex lens 8 and the fixed
convex lens 9 becomes designated value, just can satisfy the incident requirement of this device.