The Wavenumber Spectra and Standard Deviations of Uncorrelated Errors in SWOT Measurements of Sea-Surface Height for Various Footprint Sizes
The Wavenumber Spectra and Standard Deviations of Uncorrelated Errors in SWOT Measurements of Sea-Surface Height for Various Footprint Sizes
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不同足迹尺寸海面高度SWOT测量中不相关误差的波数谱和标准差
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发表时间：
2019
期刊：
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通讯作者：
D. Chelton
中科院分区：
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作者：
D. Chelton
。海面高度 SWOT 测量误差的科学要求规范在使用 15 km 半功率滤波器截止波长平滑数据后以沿轨迹波数谱的形式表示。对于想要分析 SWOT 数据而不应用 15 公里平滑的用户来说，这种测量误差的表达方式很不方便。更高分辨率的 SWOT 数据主要受到不相关仪器噪声对总测量误差的影响。本说明的目的是从科学要求规范中推导出 0.5 公里、1.0 公里和 2.0 公里足迹尺寸的相应波数谱和不相关测量误差的标准偏差，并且在跨轨道维度上没有 15 公里平滑。分析假设对于每个足迹尺寸，不相关误差的光谱在波长短于 15 km 时为白色。海面高度测量误差可分为不相关测量误差和长波长误差，其中长波长误差可归因于轨道高度误差、天线指向误差、显着波高效应造成的偏差误差以及各种地球物理效应对距离估计的修正误差。跨轨 沿轨波数
. The science requirement specification of the errors in SWOT measurements of sea-surface height is expressed in the form of an along-track wavenumber spectrum after smoothing the data with a half-power filter cutoff wavelength of 15 km. This expression of the measurement errors is inconvenient for users who want to analyze SWOT data without applying 15-km smoothing. Higher-resolution SWOT data are primarily affected by the contribution of uncorrelated instrumental noise to the total measurement errors. The purpose of this note is to derive from the science requirement specification the corresponding wavenumber spectra and standard deviations of the uncorrelated measurement errors for footprint sizes of 0.5 km, 1.0 km and 2.0 km, without 15-km smoothing in the across-track dimension. The analysis assumes that the spectra of the uncorrelated errors are white at wavelengths shorter than 15 km for each of these footprint sizes. The errors of measurements of sea surface height can be partitioned into a contribution from uncorrelated measurement errors and a contribution from long-wavelength errors attributable to orbit height errors, antenna pointing errors, errors in biases from significant wave height effects, and errors in the corrections for various geophysical effects on the range estimates. across-track along-track wavenumber