CN103389073A - Method for selecting satellite-to-ground matched data through water-color remote sensing - Google Patents

Abstract

The invention discloses a method for selecting satellite-to-ground matched data through water-color remote sensing. The method comprises the following steps: aiming at a certain sea area, acquiring satellite remote sensing reflectance data of a static orbit satellite within a period of at least continuous three hours in the sea area; calculating the spatial distribution of optical water body factors in the sea area according to each satellite remote sensing reflectance datum; calculating the change distribution of the optical water body factors in the sea area by adopting a feature extraction algorithm to obtain credible time periods of different regions in the sea area, and further determining the satellite-to-ground matched data. The method disclosed by the invention is simple and easy to implement and capable of effectively ensuring the reliability of the satellite-to-ground matched data.

Description

The choosing method of a kind of Ocean Color Remote Sensing star ground matched data

Technical field

The present invention relates to the ocean remote sensing technical field, relate in particular to the choosing method of a kind of Ocean Color Remote Sensing star ground matched data.

Background technology

Water constituent concentration information on a large scale can be synchronously obtained in ocean color remote sensing, such as chlorophyll, suspension etc., bringing into play irreplaceable vital role in the research such as sea fishery, marine ecosystems, ocean water quality environment and application, is the important means that ocean surface is surveyed.The operation of current Ocean Color Remote Sensing business mostly is open ocean preferably, the perhaps optical property water body of homogeneous comparatively, in coastal waters than feculent water body, application power and degree are also lower, it mainly is subject to authenticity verification, namely select star ground matched data, the result of remote-sensing inversion is compared, with the accuracy of evaluation remote sensing algorithm and the availability of Remote Sensing Products.

And a difficult point of authenticity verification is to choose star ground matched data.

In fact strict, star ground matched data must be both precise synchronizations, i.e. the data of field observation and moonscope data be precise synchronization in time.Ocean Color Remote Sensing is subjected to the meteorological conditions such as cloud to affect very serious, because field observation can't be predicted the air space above sea weather conditions in advance, and satellite scanning to obtain a scape image be approximately 5 minutes (take AQUA MODIS as example), want to obtain corresponding field observation in satellite passes by the time period of obtaining image, be difficult to realize.

In view of the situation, prior art is often passed by satellite and was set as time synchronized in 1 hour when choosing star ground matched data, perhaps time synchronized is elected as 3 hours to a greater degree,, to obtain relatively accurate star ground, this zone matched data, carried out the checking of Ocean Color Remote Sensing product authenticity.

The relative ocean of Changes in weather, overhead, offshore sea waters are more complicated, and water body is comparatively muddy, complicated Hydrodynamic Process causes water body optical property and water constituent to present higher spatial-temporal characteristics, prior art is only applicable to water body optical property comparatively homogeneous or the comparatively stable waters of water constituent, can't guarantee the reliability of star ground matched data in offshore sea waters.

Summary of the invention

Technical matters to be solved by this invention is the defect for background technology, and a kind of Ocean Color Remote Sensing star ground matched data choosing method that can effectively guarantee star ground matched data reliability is provided.

The present invention is for solving the problems of the technologies described above by the following technical solutions:

The choosing method of a kind of Ocean Color Remote Sensing star ground matched data, the concrete steps of choosing star ground matched data for a certain marine site are as follows:

Step 1), obtain the satellite remote sensing reflectivity data of the continuous at least three hours satellites in this marine site;

Step 2), after gained satellite remote sensing reflectivity data is carried out preliminary atmospheric correction, the pixel of removing land and affected by cloud;

Step 3), calculate the time period distribution trusty of this marine site;

Step 4), filter out the star ground matched data in the time period distribution trusty of this marine site from existing star ground matched data.

As the further preferred version of the present invention, described to calculate the concrete steps that this marine site time period trusty distributes as follows:

Step 301),, to satellite remote sensing reflectivity data each time, choose the wave band of image study object water body optical signature, the water body optics factor space that calculates this marine site distributes, and the computing formula of water body optics factor Cindx is as follows:

${\mathrm{Cindx}}_j=\frac{\mathrm{\Σ}{A}_i{R}_{i,j}}{r_j}$

Wherein, A is weight coefficient, and R is the remote sensing reflectivity after preliminary atmospheric correction, i=1,2,, m is selected wave band number, j=1,2, n is pixel point number in image, and r represents the average remote sensing reflectivity of the wave band of remote sensing reflectivity sum maximum, and m, n are and are greater than or equal to 1 natural number;

Step 302), adopt feature extraction algorithm, the water body optics factor variations that calculates this marine site distributes;

Step 303), the value that setting is no more than the water body optics factor mean value 10% of all satellite remote sensing reflectivity datas of this marine site is threshold value, chooses water body optics factor numerical value and is less than or equal to the time period distribution of this threshold value as the time period distribution trusty of this zone.

As the further preferred version of the present invention, described satellite adopts the GOCI satellite.

The present invention adopts above technical scheme compared with prior art, has following technique effect:

1. be simple and easy to realize;

2. effectively guarantee the reliability of star ground matched data.

Description of drawings

Fig. 1 is process flow diagram of the present invention.

Embodiment

Below in conjunction with accompanying drawing, technical scheme of the present invention is described in further detail:

As shown in Figure 1, the present embodiment discloses the choosing method of a kind of Ocean Color Remote Sensing star ground matched data, and selecting eastern China sea zone is survey region, and concrete steps are as follows:

Step 1), obtain the satellite remote sensing reflectivity data of the continuous at least three hours GOCI satellites in this marine site;

Step 2), after gained satellite remote sensing reflectivity data is carried out preliminary atmospheric correction (Rayleigh correction), the pixel of removing land and affected by cloud;

Step 3), to satellite remote sensing reflectivity data each time, the water body optics factor space that the data of choosing the 1st wave band, the 2nd wave band, the 4th wave band, the 6th wave band and the 8th wave band are calculated this marine site distributes, and the computing formula of water body optics factor Cindx is as follows:

${\mathrm{Cindx}}_j=\frac{\mathrm{\Σ}{A}_i{R}_{i,j}}{r_j}$

Wherein, A is weight coefficient, and R is the remote sensing reflectivity after preliminary atmospheric correction, i=1,2,, m is selected wave band number, j=1,2, n is pixel point number in image, and r represents the average remote sensing reflectivity of the wave band of remote sensing reflectivity sum maximum, and m, n are and are greater than or equal to 1 natural number;

Step 4), adopt feature extraction algorithm, and the water body optics factor variations that calculates this marine site distributes;

Step 5), the value that setting is no more than the water body optics factor mean value 10% of all satellite remote sensing reflectivity datas of this marine site is threshold value, chooses water body optics factor numerical value and is less than or equal to the time period distribution of this threshold value as the time period distribution trusty of this zone;

Step 6), filter out the star ground matched data in the time period distribution trusty of this marine site from existing star ground matched data.

Claims (3)

1. the choosing method of an Ocean Color Remote Sensing star ground matched data, is characterized in that, the concrete steps of choosing star ground matched data for a certain marine site are as follows:

Step 1), obtain the satellite remote sensing reflectivity data of the continuous at least three hours satellites in this marine site;

Step 2), after gained satellite remote sensing reflectivity data is carried out preliminary atmospheric correction, the pixel of removing land and affected by cloud;

Step 3), calculate the time period distribution trusty of this marine site;

Step 4), filter out the star ground matched data in the time period distribution trusty of this marine site from existing star ground matched data.

2. the choosing method of a kind of Ocean Color Remote Sensing star according to claim 1 ground matched data is characterized in that the concrete steps of step 3) are as follows:

Step 301),, to satellite remote sensing reflectivity data each time, choose the wave band of image study object water body optical signature, the water body optics factor space that calculates this marine site distributes, and the computing formula of water body optics factor Cindx is as follows:

${\mathrm{Cindx}}_j=\frac{\mathrm{\Σ}{A}_i{R}_{i,j}}{r_j}$

Wherein, A is weight coefficient, and R is the remote sensing reflectivity after preliminary atmospheric correction, i=1,2,, m is selected wave band number, j=1,2, n is pixel point number in image, and r represents the average remote sensing reflectivity of the wave band of remote sensing reflectivity sum maximum, and m, n are and are greater than or equal to 1 natural number;

Step 302), adopt feature extraction algorithm, the water body optics factor variations that calculates this marine site distributes;

Step 303), the value that setting is no more than the water body optics factor mean value 10% of all satellite remote sensing reflectivity datas of this marine site is threshold value, chooses water body optics factor numerical value and is less than or equal to the time period distribution of this threshold value as the time period distribution trusty of this zone.

3. the choosing method of a kind of Ocean Color Remote Sensing star according to claim 1 ground matched data, is characterized in that, described satellite adopts the GOCI satellite.

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