Method for Identifying Sunny and Rainy Moments by Utilizing Multiple Characteristic Quantities of High-frequency Satellite-ground Links

A method for identifying sunny and rainy moments by utilizing multiple characteristic quantities of high-frequency satellite-ground links, comprising the following steps:

• step 1:
• establishing high-frequency satellite-ground links;
• step 2:
• carrying out time domain sampling on the high-frequency satellite-ground links at intervals of ΔT to obtain an original received signal SN;
• step 3:
• filtering the original received signal SN with a wavelet analysis method and eliminating changes caused by tropospheric scintillation to obtain a signal S(n);
• step 4:
• extracting characteristic quantities of the signal S(n), for the signal S(n) at each moment;
• step 5:
• adjusting a calculation window area Wi of each of the characteristic quantities, and selecting an optimal time window W;
• step 6:
• representing eigenvectors composed of the characteristic quantities obtained by the step 4 of two signals at different moments with x1 and x2, selecting a Gaussian kernel function K(x1, x2) and a penalty factor C:
• K
• ⁡
• (
• x
• 1
• ,
• x
• 2
• )
• =
• exp
• ⁡
• (
• -
• 
• x
• 1
• -
• x
• 2
• 
• 2
• ⁢
• σ
• 2
• )
• where σ represents a bandwidth and is used for controlling an action range of the Gaussian kernel function;
• and constructing an optimization problem:
• min
• α
• ⁢
• 1
• 2
• ⁢
• ∑
• i
• =
• 1
• n
• ⁢
• ⁢
• ∑
• j
• =
• 1
• n
• ⁢
• ⁢
• α
• i
• ⁢
• α
• j
• ⁢
• y
• i
• ⁢
• y
• j
• ⁢
• K
• ⁡
• (
• x
• i
• ,
• x
• j
• )
• -
• ∑
• i
• =
• 1
• n
• ⁢
• ⁢
• α
• i
• s
• .
• t
• .
• ⁢
• ∑
• i
• =
• 1
• n
• ⁢
• ⁢
• α
• i
• ⁢
• y
• i
• =
• 0
• 0
• ≤
• α
• i
• ≤
• C
• where y represents classification results, and a represents a Lagrange multiplier;
• step 7:
• solving an optimal α based on a quadratic programming problem, and constructing a decision function G(x) to distinguish between sunny and rainy moments:
• G
• ⁡
• (
• x
• i
• )
• =
• sign
• (
• ∑
• i
• ⁢
• α
• i
• ⁢
• y
• i
• ⁢
• K
• ⁡
• (
• x
• i
• ,
• x
• j
• )
• +
• b
• )
• b
• =
• y
• j
• -
• ∑
• i
• ″
• ∈
• SV
• ⁢
• α
• i
• ″
• ⁢
• y
• i
• ″
• ⁢
• K
• ⁡
• (
• x
• j
• ,
• x
• i
• ″
• )
• where SV represents a support vector.