SU1631370A1 - Method of determining bio-productivity of plankton - Google Patents

Abstract

The invention relates to optical methods for studying the natural resources of the Earth by remote sensing methods. The aim of the invention is to expand the range of measured parameters. The method allows the detection of low-contrast bioproductive objects and an estimate of the concentration of plankton on the color tone of the image synthesized from two zonal images formed in spectral zones from 1 to 12 nm wide within the ranges of 550-580 and 650-680 nm, and the zonal brightness images in the range of 550-580 nm are reduced to a level of about 50% when visually detected or to a level of about 10% when recorded by physical radiation receivers. 2 Il. v ё

Description

The invention relates to optical methods for studying the natural resources of the Earth by remote sensing and can be used to detect bioproductive zones that are low-contrast objects, as well as to classify them by the concentration of plankton.

The purpose of the invention is to expand the range of measured parameters for determining the biological productivity by the value of the concentration of plankton.

FIG. 1 shows a device for implementing the method for visual registration; in fig. 2 - spectral luminances of four types of bioproductive waters.

The device contains a lens 1 and a 2-division system of translucent and

reflecting mirrors with the help of which two optical channels are formed, one of which contains successively located adjustable aperture 3, a neutral filter 4 and an interference filter 5 with a spectral transmission range of 550-580 nm, and the other with an interference spectrum of 650-680 nm, at the output of which is placed the system 7 combining optical images from a translucent and reflecting mirrors, behind which the lens 8 and the prism 9 combining are placed, on one of the faces to using the lens 10, an image of the color scale 11 is generated, illuminated by a standard light source 12, as well as an image recorder

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of brazil Evaluation of the latter can be performed visually with the help of an ocular 13 or with other optical radiation receivers.

The device works as follows.

The luminous flux of an object is formed by lens 1 and is split into two parts using the light-separation system 3, one of which is attenuated by a neutral light filter 4, respectively, to a level of about 50% (g 0.5) upon visual registration and to a level of the order of 10% (t 0.1) when registering by other optical radiation receivers and the diaphragm 3, which performs additional attenuation control for specific observation conditions, falls on an interference optical filter 5 with a passband from 1 to 12 nm in the range 550-580 nm forming th one of the image zone, and the other passes through an interference filter 6 with a passband from 1 to 12 nm in the range 650-680 nm, forming a second zone of the image. In this case, both zonal images fall into the registration system 7, which forms a synthesized image focused by the lens 8 on one of the faces of the combination prism 9. On the other side of the latter, an image of a color scale 11, illuminated by a standard source 12 of light, is formed using a lens 10. Moreover, both images are observed by the operator through the ocular p 13.

The color scale is a set of color colors imitating the color of the synthesized image of an object at different values of plankton concentration, as well as digitizing these values in terms of the concentration of plankton in a suspension of seawater (mg / m). In order to take into account the influence of specific observation conditions and the subjective properties of the operator's analyzer, the color scale is calibrated for areas with clear water, as a rule, being the background, and for a special color world reproducing the color scale used. For example, color scales may be used that simulate various types of interference (atmospheric mist, pollution and salinity, etc.).

The width of the spectral zone from 1 nm to. 12 nm is determined from the following. : 1 nm - the minimum value of the working channel (resolution) of the modern spectral equipment used

in spectrometry of natural objects (for example, the resolution of the CXR spectral spectrometer NRB Spectrum-256 from 1 nm to 2.5 nm) (and 12 nm is determined by the shape of the real spectral curves of the studied objects (Fig. 2), where the width of the peaks and valleys is 12 nm .

The boundary values of the spectral ranges are determined by the specific course of the experimentally obtained spectral curves. Moreover, the value of 550 nm is the minimum wavelength at which the strong influence of the atmosphere ceases to affect, and the value of 680 nm determines the upper limit of wavelengths in the visible range, where a difference in the spectral curves of different plankton species appears. As a result of experimental spectral studies of plankton in apparent composition and in various regions of the oceans, it was revealed that their characteristic zones can vary in the range not exceeding 30 nm, and therefore the values of the spectral ranges of 550-580 and 650-680 are determined. nm.

The method for determining the bio-productivity of plankton is based on the following.

Using the experimental spectrometric data on various types of bioproductive seawater, shown in FIG. 2, where the content of plankton is from 2 to 10 mg / m and more corresponds to curve 14, from 0.5 to 5.0 mg / m - curve 15, from 0.2 to 1.0 kg / m - curve 16, less than 0.5 mg / m - curve 17. It is possible to determine that, when directly observed, their range of color difference is no more than three color difference thresholds for four types of bioproductive waters. Moreover, the presence of atmospheric haze at the time of observation reduces this value to one color difference threshold. Based on the form of the indicated spectral curves, two informative ranges are distinguished - 550-580; 650–680 nm, characterizing the maximum differences of the four types of bioproductive waters and free from the influence of atmospheric haze, which already have little effect on wavelengths longer than 540–550 nm.

The choice of the spectral band width of not more than 12 nm is determined by a discrete change in the course of the spectral curves. However, this choice of spectral zones and ranges only slightly expands the range of color discrimination. This is due to the fact that the luminous flux from bioproductive objects in the range of 550-580 nm is much higher than the luminous flux in the range of 650-680 nm.

attenuate the light flux in the range of 550-580 nm. The magnitude of attenuation can be estimated using the dependence of the range of variation of the dominant wavelengths of the synthesized image for four types of water on the degree of suppression of the light flux within 550-580 nm. Suppression up to a level of 10% is optimal.

Based on the specifics of visual perception of optical radiation, an optimal color difference is calculated, which is obtained by suppressing the light flux in the range of 550-680 nm to a level of about 50%. The dependence of the concentration of plankton in the suspension of seawater on the dominant wavelength of the synthesized image or, taking into account the peculiarities of visual perception, on the number of color difference thresholds is determined. The magnitude of the obtained range of color difference makes it possible to reliably recognize bioproductive objects according to the degree of plankton concentration.

The presence of external adverse observation conditions, such as increased atmospheric haze density, seawater pollution, the presence of suspensions, worsens the range of color difference, but for these four types of bioproductive waters, the possibility of reliable color difference remains. In addition, adjustment can be made to specific observation conditions by changing the spectral zones within the ranges 550-580 and 650-680 nm and changing the fraction of the light flux in the range 550-580 nm in total

luminous flux in order to increase the range of color difference.

The method allows visually or in automatic mode to quickly detect the bioproductive zones in the oceans and inland waters and to determine the concentration of plankton in them. The method is remote, it can be used when working on any carriers - marine,

at the same time, it allows to increase the range of color difference from 1 to 14 thresholds. This makes it possible not only to isolate a bioproductive object from the background, but also to classify it by

Claims (1)

plankton content, which makes it possible to evaluate its potential for commercial purposes. In addition, it is possible to quickly assess the environmental situation of the regions. Invention Formula The method for determining the bioproductivity of plankton, which consists in forming - zonal-h images in two channels, changing the strengths of the obtained images, combining and recording them, characterized in that, in order to expand the range of measured parameters, the formation of zonal images produce spectral zones from 1 to 12 nm wide within 550580 nm for the first and 650-680 nm DLR of the second channel, while the brightness of the zonal image in the first channel reduced to a level of 50% when visually registered or to a level of 10% when registered by physical radiation receivers and the color tone of the obtained image, the concentration of plankton is established. f P / I J 4 5 sh I P -a / 1 Sh 500 550 580 600 650 680 - fm.g eight $ & - $ - / / iI /    / , NM