CN110288117A - A kind of regional restructuring method of Ionospheric Parameters critical frequency - Google Patents

A kind of regional restructuring method of Ionospheric Parameters critical frequency Download PDF

Info

Publication number
CN110288117A
CN110288117A CN201910389146.2A CN201910389146A CN110288117A CN 110288117 A CN110288117 A CN 110288117A CN 201910389146 A CN201910389146 A CN 201910389146A CN 110288117 A CN110288117 A CN 110288117A
Authority
CN
China
Prior art keywords
latitude
fof2
longitude
critical frequency
mesh point
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN201910389146.2A
Other languages
Chinese (zh)
Other versions
CN110288117B (en
Inventor
孙秀志
贾文科
韩阳
姬生云
韩峰
王健
杨铖
苏海斌
付炜
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
31007 Army Of Chinese People's Liberation Army
Qingdao Agricultural University
China Research Institute of Radio Wave Propagation CRIRP
Original Assignee
31007 Army Of Chinese People's Liberation Army
Qingdao Agricultural University
China Research Institute of Radio Wave Propagation CRIRP
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 31007 Army Of Chinese People's Liberation Army, Qingdao Agricultural University, China Research Institute of Radio Wave Propagation CRIRP filed Critical 31007 Army Of Chinese People's Liberation Army
Priority to CN201910389146.2A priority Critical patent/CN110288117B/en
Publication of CN110288117A publication Critical patent/CN110288117A/en
Application granted granted Critical
Publication of CN110288117B publication Critical patent/CN110288117B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
    • G06Q10/00—Administration; Management
    • G06Q10/04—Forecasting or optimisation specially adapted for administrative or management purposes, e.g. linear programming or "cutting stock problem"

Landscapes

  • Engineering & Computer Science (AREA)
  • Business, Economics & Management (AREA)
  • Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Strategic Management (AREA)
  • Human Resources & Organizations (AREA)
  • Economics (AREA)
  • General Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • Development Economics (AREA)
  • Geometry (AREA)
  • Game Theory and Decision Science (AREA)
  • Evolutionary Computation (AREA)
  • Computer Hardware Design (AREA)
  • Entrepreneurship & Innovation (AREA)
  • Marketing (AREA)
  • Operations Research (AREA)
  • Quality & Reliability (AREA)
  • Tourism & Hospitality (AREA)
  • General Business, Economics & Management (AREA)
  • Position Fixing By Use Of Radio Waves (AREA)

Abstract

The invention discloses a kind of regional restructuring methods of Ionospheric Parameters critical frequency, it includes the following steps, step A: reading the longitude and latitude of detection site, the Ionospheric Parameters foF2 and detection time of real-time detection；Step B: selecting the region of Ionospheric reconstruction, determines mesh point warp, latitude；Step C: by the time of input, the Ionospheric Parameters foF2 on these mesh points is calculated using China reference ionosphere；Step D: ionosphere characterisitic parameter foF2 is reconstructed using Kalman filter assimilation method.Beneficial effect is: invention introduces real-time detection datas, and fusion amendment has been carried out on the basis of China reference ionosphere, and the accuracy of forecast result is higher, provide more reliable data support for short wave communication frequency-selecting.The present invention is based on the regional restructuring methods of the ionospheric critical frequency foF2 of Kalman filter, the Ionospheric Parameters foF2 based on real-time detection, can be realized more accurate regional restructuring forecast.

Description

A kind of regional restructuring method of Ionospheric Parameters critical frequency
Technical field
The invention belongs to a kind of ionosphere characteristic computing methods, and in particular to a kind of area of Ionospheric Parameters critical frequency Domain reconstructing method.
Background technique
China reference ionosphere and international reference ionosphere disclose a kind of ionosphere characterisitic parameter based on historical data Forecasting procedure, detection data of this method based on dozens of website obtain the statistics of Ionospheric variability by statistical analysis Model carries out the prediction of ionosphere characterisitic parameter according to sunspot number.The shortcomings that model is can only to predict the statistics middle of the month Value, real-time prediction result precision are lower.
Summary of the invention
It is an object of the invention to provide a kind of regional restructuring methods of Ionospheric Parameters critical frequency, it overcomes Chinese ginseng Examine ionosphere can only predicted month intermediate value the shortcomings that, realize the forecast of more accurate regional restructuring.
Technical scheme is as follows: a kind of regional restructuring method of Ionospheric Parameters critical frequency, it includes as follows Step,
Step A: the longitude and latitude of detection site, the F2 layer critical frequency foF2 and detection time of real-time detection are read；
Step B: selecting the region of Ionospheric reconstruction, determines mesh point warp, latitude；
Step C: by the time of input, the critical frequency of F2 layer on these mesh points is calculated using China reference ionosphere Rate foF2；
Step D: F2 layers of critical frequency foF2 are reconstructed using Kalman filter assimilation method.
The unit of longitude and latitude in the step A is " degree ", when detection time includes year, month, day and Beijing.
Region in the step B is rectangular area, including minimum and maximum longitude and latitude, grid interval size, most The unit of greatly/minimum longitude and latitude and grid interval size is " degree ".
The step B includes the following steps:
Step B1: mesh point latitude vector λ is calculatedi,λminAnd λmaxRespectively represent minimum latitude and maximum latitude, λdIt indicates Gap size of the grid on latitude direction, λnFor latitudinal mesh point quantity,
λn=int [(λmax-λmin)/λd]+1
λi=(λmin,λmin+λd,λmin+2×λd,……,λmin+i×λd,……,λmin+λn×λd,λmax)
Step B2: mesh point longitude vector θ is calculatedi, θminAnd θmaxRespectively represent minimum longitude and maximum longitude, θdIt indicates Gap size of the grid in longitudinal, θmFor the mesh point quantity of longitudinal；
θm=int [(θmax-θmin)/θd]+1
θi=(θmin,θmin+θd,θmin+2×θd,θmin+i×θd,……,θmin+θm×θd,θmax)
Step B3: the mesh point longitude and latitude matrix of reconstruction region is generated；
When the step C judges that the time inputted in China reference ionosphere is universal time or Beijing, if the world When, then it is converted when needing with Beijing, conversion formula is BT (when Beijing)=UT (universal time)+8；If when Beijing, not into Row conversion.
The step D includes the following steps,
Step D1: background error covariance matrix P is calculatedb, refer to that China reference ionosphere calculates the moon of sensing point position The covariance of median result and actual detection data error；
Step D2: calculating the correlation matrix of ambient field, calculates the ginseng such as each mesh point longitude and latitude, foF2 with Euclidean distance Several distances calculates correlation matrix R using Gauss correlation function, and wherein there are three variables in the calculation formula of Euclidean distance, divides It is not that latitude, longitude and F2 layers of critical frequency foF2, F2 layers of critical frequency foF2 therein are obtained by China reference ionosphere calculating , mesh point longitude and latitude is calculated by step B and is obtained,
In formula, faAnd fbRespectively different mesh point a and b corresponding F2 layers of critical frequency foF2, unit MHz, λa, λb The corresponding latitude of respectively different mesh point a and b, θa, θbThe corresponding longitude of respectively different mesh point a and b, l is feature ruler Degree, is selected as 0.01；
Step D3: gain matrix K is calculated；
K=PbHT(HPbHT+R)-1
Wherein, H is Observation Operators,
H=E, i.e. H (i, j)=1
Step D4: F2 layers of critical frequency foF2 of predicted grid point；
xa=xb+K(x°-Hxb)
Wherein, xaFor prediction result, xbFor Reference ionosphere calculated result, x°For real-time detection result.
The beneficial effects of the present invention are: invention introduces real-time detection datas, in the base of China reference ionosphere Fusion amendment is carried out on plinth, the accuracy of forecast result is higher, provides more reliable data support for short wave communication frequency-selecting. The present invention is based on the regional restructuring methods of the F2 of Kalman filter layer critical frequency foF2, and the F2 layer based on real-time detection is critical Frequency foF2 can be realized more accurate regional restructuring forecast.
Specific embodiment
Invention is further described in detail combined with specific embodiments below.
A kind of regional restructuring method of Ionospheric Parameters critical frequency of the present invention is with the forecast result of China reference ionosphere As ambient field data, using real-time detection data as observation field data, using Kalman filter assimilation method, by background Field and observation field data are merged, to realize the regional restructuring of real-time ionospheric characterisitic parameter.Specific step is as follows:
Step A: the longitude and latitude of detection site, the F2 layer critical frequency foF2 and detection time of real-time detection are read.This The unit of longitude and latitude is " degree " in invention, when detection time includes year, month, day and Beijing.
Step B: selecting the region of Ionospheric reconstruction, determines mesh point warp, latitude.Region in the present invention is rectangle region Domain, including minimum and maximum longitude and latitude, grid interval size.The unit of maximum/minimum longitude and latitude and grid interval size is " degree ".
Further, step B is specifically described as follows:
Step B1: mesh point latitude vector λ is calculatedi,λminAnd λmaxRespectively represent minimum latitude and maximum latitude, λdIt indicates Gap size of the grid on latitude direction, λnFor latitudinal mesh point quantity,
λn=int [(λmax-λmin)/λd]+1
λi=(λmin,λmin+λd,λmin+2×λd,……,λmin+i×λd,……,λmin+λn×λd,λmax)
Step B2: mesh point longitude vector θ is calculatedi, θminAnd θmaxRespectively represent minimum longitude and maximum longitude, θdIt indicates Gap size of the grid in longitudinal, θmFor the mesh point quantity of longitudinal.
θm=int [(θmax-θmin)/θd]+1
θi=(θmin,θmin+θd,θmin+2×θd,θmin+i×θd,……,θmin+θm×θd,θmax)
Step B3: the mesh point longitude and latitude matrix of reconstruction region is generated.
Step C: by the time of input, the Ionospheric Parameters on these mesh points are calculated using China reference ionosphere foF2.In the present invention it should be noted that when the time inputted in China reference ionosphere is universal time or Beijing, if the world When, then it is converted when needing with Beijing, conversion formula is BT (when Beijing)=UT (universal time)+8；If when Beijing, then not It is converted.
Step D: F2 layers of critical frequency foF2 are reconstructed using Kalman filter assimilation method.
Further, step B is specifically described as follows:
Step D1: background error covariance matrix P is calculatedb, refer mainly to China reference ionosphere and calculate sensing point position The moon median result and actual detection data error covariance.
Step D2: the correlation matrix of ambient field is calculated, utilizes each mesh point longitude and latitude of Euclidean distance calculating in the present invention The distance of the parameters such as degree, foF2 calculates correlation matrix R using Gauss correlation function.Here have in the calculation formula of Euclidean distance Three variables are latitude, longitude and F2 layers of critical frequency foF2 respectively, and F2 layer critical frequency foF2 here is referred to by China Ionosphere, which calculates, to be obtained, and mesh point longitude and latitude is calculated by step B and obtained.
In formula, faAnd fbRespectively different mesh point a and b corresponding foF2, unit MHz.
λa, λbThe corresponding latitude of respectively different mesh point a and b；
θa, θbThe corresponding longitude of respectively different mesh point a and b；
L is characteristic dimension, is selected as 0.01 here.
Step D3: gain matrix K is calculated
K=PbHT(HPbHT+R)-1
Wherein, H is Observation Operators.
H=E, i.e. H (i, j)=1
Step D4: predicted grid point Ionospheric Parameters foF2.
xa=xb+K(x°-Hxb)
Wherein, xaFor prediction result, xbFor Reference ionosphere calculated result, x°For real-time detection result.
In conclusion the present invention provides a kind of F2 layer critical frequency foF2 based on Kalman filter assimilation technique Regional restructuring method.Sharpest edges of the invention are can be based on China reference ionosphere model, in conjunction with the electricity of real-time detection Absciss layer data, the reconstruct of Ionospheric Parameters foF2 is carried out to specified region, and this method accuracy with higher cuts and is easy to work Cheng Shixian.By experimental verification, the present invention is suitable for regional, can if this method is using international reference ionosphere model It is enough that region Ionospheric Parameters in global range are reconstructed.
The foregoing is only a preferred embodiment of the present invention, but protection scope of the present invention be not limited to This, anyone skilled in the art in the technical scope disclosed by the present invention, the variation that can readily occur in or replaces It changes, should be covered by the protection scope of the present invention.Therefore, protection scope of the present invention should be with the guarantor of claims It protects subject to range.

Claims (6)

1. a kind of regional restructuring method of Ionospheric Parameters critical frequency, it is characterised in that: it includes the following steps,
Step A: the longitude and latitude of detection site, the F2 layer critical frequency foF2 and detection time of real-time detection are read；
Step B: selecting the region of Ionospheric reconstruction, determines mesh point warp, latitude；
Step C: by the time of input, the Ionospheric Parameters foF2 on these mesh points is calculated using China reference ionosphere；
Step D: F2 layers of critical frequency foF2 are reconstructed using Kalman filter assimilation method.
2. a kind of regional restructuring method of Ionospheric Parameters critical frequency as described in claim 1, it is characterised in that: described The unit of longitude and latitude in step A is " degree ", when detection time includes year, month, day and Beijing.
3. a kind of regional restructuring method of Ionospheric Parameters critical frequency as described in claim 1, it is characterised in that: described Region in step B is rectangular area, including minimum and maximum longitude and latitude, grid interval size, maximum/minimum longitude and latitude and net The unit of lattice gap size is " degree ".
4. a kind of regional restructuring method of Ionospheric Parameters critical frequency as claimed in claim 1 or 3, it is characterised in that: institute The step B stated includes the following steps:
Step B1: mesh point latitude vector λ is calculatedi,λminAnd λmaxRespectively represent minimum latitude and maximum latitude, λdIndicate grid Gap size on latitude direction, λnFor latitudinal mesh point quantity,
λn=int [(λmax-λmin)/λd]+1
λi=(λmin,λmin+λd,λmin+2×λd,……,λmin+i×λd,……,λmin+λn×λd,λmax)
Step B2: mesh point longitude vector θ is calculatedi, θminAnd θmaxRespectively represent minimum longitude and maximum longitude, θdIndicate grid Gap size in longitudinal, θmFor the mesh point quantity of longitudinal；
θm=int [(θmax-θmin)/θd]+1
θi=(θmin,θmin+θd,θmin+2×θd,θmin+i×θd,……,θmin+θm×θd,θmax)
Step B3: the mesh point longitude and latitude matrix of reconstruction region is generated；
5. a kind of regional restructuring method of Ionospheric Parameters critical frequency as described in claim 1, it is characterised in that: described When step C judges that the time inputted in China reference ionosphere is universal time or Beijing, if universal time, then need and Beijing Shi Jinhang conversion, conversion formula are BT (when Beijing)=UT (universal time)+8；If when Beijing, without conversion.
6. a kind of regional restructuring method of Ionospheric Parameters critical frequency as described in claim 1, it is characterised in that: described Step D includes the following steps,
Step D1: background error covariance matrix P is calculatedb, refer to that China reference ionosphere calculates the moon intermediate value knot of sensing point position The covariance of fruit and actual detection data error；
Step D2: calculating the correlation matrix of ambient field, calculates each mesh point longitude and latitude, F2 layers of critical frequency with Euclidean distance The distance of foF2 calculates correlation matrix R using Gauss correlation function, wherein in the calculation formula of Euclidean distance there are three variable, It is latitude, longitude and F2 layers of critical frequency foF2 respectively, F2 layers of critical frequency foF2 therein is calculated by China reference ionosphere It obtaining, mesh point longitude and latitude is calculated by step B and is obtained,
In formula, faAnd fbRespectively different mesh point a and b corresponding foF2, unit MHz, λa, λbRespectively different mesh point a Latitude corresponding with b, θa, θbThe corresponding longitude of respectively different mesh point a and b, l is characteristic dimension, is selected as 0.01；
Step D3: gain matrix K is calculated；
K=PbHT(HPbHT+R)-1
Wherein, H is Observation Operators,
H=E, i.e. H (i, j)=1
Step D4: F2 layers of critical frequency foF2 of predicted grid point；
xa=xb+K(xo-Hxb)
Wherein, xaFor prediction result, xbFor Reference ionosphere calculated result.
CN201910389146.2A 2019-05-10 2019-05-10 Regional reconstruction method for critical frequency of ionosphere parameters Active CN110288117B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910389146.2A CN110288117B (en) 2019-05-10 2019-05-10 Regional reconstruction method for critical frequency of ionosphere parameters

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910389146.2A CN110288117B (en) 2019-05-10 2019-05-10 Regional reconstruction method for critical frequency of ionosphere parameters

Publications (2)

Publication Number Publication Date
CN110288117A true CN110288117A (en) 2019-09-27
CN110288117B CN110288117B (en) 2021-06-29

Family

ID=68001925

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910389146.2A Active CN110288117B (en) 2019-05-10 2019-05-10 Regional reconstruction method for critical frequency of ionosphere parameters

Country Status (1)

Country Link
CN (1) CN110288117B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110909447A (en) * 2019-10-19 2020-03-24 中国电波传播研究所（中国电子科技集团公司第二十二研究所） High-precision short-term prediction method for ionization layer region
CN110909449A (en) * 2019-10-19 2020-03-24 中国电波传播研究所（中国电子科技集团公司第二十二研究所） Multi-source data ionization layer region reporting method
CN112272067A (en) * 2020-10-15 2021-01-26 天津大学 Short wave broadcast frequency scheduling method based on multi-source data processing

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050148346A1 (en) * 2003-12-30 2005-07-07 Maloney John E. TDOA/GPS hybrid wireless location system
EP3109672A1 (en) * 2015-06-24 2016-12-28 Centre National d'Etudes Spatiales Gnss receiver with a capability to resolve ambiguities using an uncombined formulation
CN106788815A (en) * 2016-11-28 2017-05-31 北京航空航天大学 A kind of short wave communication reliability estimation method based on many system detection datas
CN107113054A (en) * 2014-12-11 2017-08-29 天波网络有限责任公司 Use low delay/low data bandwidth and the communication means and system of high delay/high data bandwidth passage
CN107911185A (en) * 2017-11-03 2018-04-13 中国电波传播研究所（中国电子科技集团公司第二十二研究所） A kind of maximum usable frequency computational methods suitable for short-wave link during ionospheric storm

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050148346A1 (en) * 2003-12-30 2005-07-07 Maloney John E. TDOA/GPS hybrid wireless location system
CN107113054A (en) * 2014-12-11 2017-08-29 天波网络有限责任公司 Use low delay/low data bandwidth and the communication means and system of high delay/high data bandwidth passage
EP3109672A1 (en) * 2015-06-24 2016-12-28 Centre National d'Etudes Spatiales Gnss receiver with a capability to resolve ambiguities using an uncombined formulation
CN106788815A (en) * 2016-11-28 2017-05-31 北京航空航天大学 A kind of short wave communication reliability estimation method based on many system detection datas
CN107911185A (en) * 2017-11-03 2018-04-13 中国电波传播研究所（中国电子科技集团公司第二十二研究所） A kind of maximum usable frequency computational methods suitable for short-wave link during ionospheric storm

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
汤 军、姬生云、王 健、王先义: "短波通信选频中的电离层同化短期预报方法", 《电波科学学报》 *
王健、姬生云、王洪发、卢冬鸣、王先义: "基于斜向探测最高可用频率反演电离层参数", 《空间科学学报》 *
赵晶晶: "区域电离层电子密度反演与重构技术研究", 《中国博士学位论文全文 基础科学辑》 *
陈 春、宋 磊、班盼盼、孙树计: "中国地区电离层ｆｏＦ２的重构方法研究", 《电波科学学报》 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110909447A (en) * 2019-10-19 2020-03-24 中国电波传播研究所（中国电子科技集团公司第二十二研究所） High-precision short-term prediction method for ionization layer region
CN110909449A (en) * 2019-10-19 2020-03-24 中国电波传播研究所（中国电子科技集团公司第二十二研究所） Multi-source data ionization layer region reporting method
CN112272067A (en) * 2020-10-15 2021-01-26 天津大学 Short wave broadcast frequency scheduling method based on multi-source data processing
CN112272067B (en) * 2020-10-15 2022-04-08 天津大学 Short wave broadcast frequency scheduling method based on multi-source data processing

Also Published As

Publication number Publication date
CN110288117B (en) 2021-06-29

Similar Documents

Publication Publication Date Title
Kim et al. Evaluation of precipitation extremes over the Asian domain: observation and modelling studies
CN108760643B (en) Drought remote sensing monitoring method suitable for high-altitude area
Rajeevan et al. Development of a high resolution daily gridded rainfall data for the Indian region
Kajikawa et al. A multi-time scale Australian monsoon index
Sneeuw et al. Estimating runoff using hydro-geodetic approaches
CN110288117A (en) A kind of regional restructuring method of Ionospheric Parameters critical frequency
Munoz et al. Varied representation of the Atlantic meridional overturning across multidecadal ocean reanalyses
Fonseca et al. High-resolution temperature datasets in Portugal from a geostatistical approach: Variability and extremes
Diallo et al. Evaluation of RegCM4 driven by CAM4 over Southern Africa: mean climatology, interannual variability and daily extremes of wet season temperature and precipitation
Cao et al. Estimation of forest structural parameters using UAV-LiDAR data and a process-based model in ginkgo planted forests
CN110399634B (en) Forecast area determination method and system based on weather system influence
Zhu et al. Evaluation of a new satellite‐based precipitation data set for climate studies in the Xiang River basin, southern China
Li et al. Streamflow responses to climate change and LUCC in a semi-arid watershed of Chinese Loess Plateau
He et al. A new DRP-4DVar-based coupled data assimilation system for decadal predictions using a fast online localization technique
Xu et al. Estimation of potential ecological carrying capacity in China
Lv et al. Towards understanding multi-model precipitation predictions from CMIP5 based on China hourly merged precipitation analysis data
Nicholas et al. Empirical downscaling of high-resolution regional precipitation from large-scale reanalysis fields
Xie et al. Investigating long-term trends of climate change and their spatial variations caused by regional and local environments through data mining
Liu et al. Unrevealing past and future vegetation restoration on the Loess Plateau and its impact on terrestrial water storage
Liu et al. Evaluating the performance of satellite-based precipitation products using gauge measurement and hydrological modeling: A case study in a dry basin of northwest China
CN113706357A (en) Regional soil erosion evaluation based on GIS and CSLE
Shi et al. Landscape changes and their ecological effects of Miaodao Archipelago with human disturbances and under natural conditions in the past 30 years
Khachoo et al. Machine Learning for Quantification of Land Transitions in Italy between 2000 and 2018 and Prediction for 2050
Schoeneberg et al. Exploring the strength and limitations of PCIC’s CMIP5 hydrologic scenarios
Thakuri et al. Potential habitat modeling of water hyacinth in lakes of Nepal using Maxent algorithm

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant