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1 Primary & Middle School Mathematics1–9 年级在线 2 High School Mathematics10–12 年级在线 3 University Mathematics — Year 1本科一年级在线 4 University Mathematics — Year 2本科二年级在线 5 University Mathematics — Year 3本科三年级在线

1 Primary & Middle School Physics1–9 年级在线 2 High School Physics10–12 年级在线 3 University Physics — Year 1本科一年级在线 4 University Physics — Year 2本科二年级在线 5 University Physics — Year 3本科三年级在线

1 School Chemistry — Grades 1 to 121–12 年级在线 2 University Chemistry — Year 1本科一年级在线 3 University Chemistry — Year 2本科二年级在线 4 University Chemistry — Year 3本科三年级在线

1 Primary & Middle School Biology1–9 年级在线 2 High School Biology10–12 年级在线 3 University Biology — Year 1本科一年级在线 4 University Biology — Year 2本科二年级在线 5 University Biology — Year 3本科三年级在线

1 Primary & Middle School Earth and Space Sciences1–9 年级在线 2 High School Earth and Space Sciences10–12 年级在线 3 University Earth and Space Sciences — Year 1本科一年级在线 4 University Earth and Space Sciences — Year 2本科二年级在线 5 University Earth and Space Sciences — Year 3本科三年级在线

1 Markets I: The Ecosystem and Exchange-Traded Markets市场在线 2 Markets II: Rates, FX and Credit市场在线 3 Markets III: Commodities, Energy and Crypto市场在线 4 Quantitative Methods方法在线 5 Derivatives and Volatility衍生品在线 6 Rates, Credit, XVA and Risk利率、信用与风险在线 7 Research Craft: Predictors, Backtests, Measurement, Portfolios研究在线 8 Strategies I: Equities and Futures策略在线 9 Strategies II: Volatility, Relative Value, Macro and the Bank Desks策略在线 10 Microstructure and Execution交易执行在线 11 Market Making and High-Frequency Trading做市在线 12 Machine Learning for Markets机器学习在线 13 Low-Latency Software技术在线 14 Networks, Hardware and Trading Infrastructure技术在线 15 Research, Data and Risk Platforms技术在线 16 The Desk and the Firm公司运营在线 17 The Industry: Firms, Roles and Careers职业发展在线 18 Interviews I: Maths, Probability and Speed职业发展在线 19 Interviews II: Markets, Trading Games and the Final Round职业发展在线 20 Interviews III: Code职业发展在线

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Earth and Space Sciences · 术语表

什么是 Spectral signature？

Definition 25.1 University Earth and Space Sciences — Year 3 · 第 25 章 — Remote Sensing and GIS

The spectral signature of a material is its reflectance as a function of wavelength, $R(\lambda)$ , the fraction of the incident radiation it reflects. Over the thermal infrared, where surfaces emit rather than reflect, the signature is the emissivity $\varepsilon(\lambda)$ ; for an opaque sample $\varepsilon = 1 - R$ .

Laboratory reflectance spectra of five surfaces (ECOSTRESS Spectral Library, reproduced through the courtesy of the Jet Propulsion Laboratory, California Institute of Technology), with the six reflective bands 2 to 7 of the Landsat 8 and 9 imager shaded. Green grass is dark in the visible, brightest in the near infrared; kaolinite is bright everywhere but for a narrow absorption at 2.2\, µ m; haematite absorbs the blue and green and reflects the red; water reflects a few percent at every wavelength. — Laboratory reflectance spectra of five surfaces (ECOSTRESS Spectral Library, reproduced through the courtesy of the Jet Propulsion Laboratory, California Institute of Technology), with the six reflective bands 2 to 7 of the Landsat 8 and 9 imager shaded. Green grass is dark in the visible, brightest in the near infrared; kaolinite is bright everywhere but for a narrow absorption at $2.2\,\text{µ}\mathrm{m}$ ; haematite absorbs the blue and green and reflects the red; water reflects a few percent at every wavelength.

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