Sampled Together: Assessing the Value of Simultaneous Co-located Measurements

TL;DR

This paper introduces a quantitative metric to evaluate the representativeness of non-simultaneous, co-located observations, aiding in satellite network design by quantifying decorrelation in space and time.

Contribution

It applies a known data assimilation metric to assess the value of simultaneous measurements in a new context, enabling better satellite constellation and observation network decisions.

Findings

Quantifies representativity errors due to spatial and temporal separations.

Provides a method to estimate errors without prior instrument performance data.

Assists in designing satellite networks with optimal observation strategies.

Abstract

This work applies a quantitative metric well-known to the data assimilation community to a new context in order to capture the relative representativeness of non-simultaneous or non-co-located observations and quantify how these observations decorrelate in both space and time. This methodology allows for the effective determination of thresholding decisions for representative matchup conditions, and is especially useful for informing future network designs and architectures. Future weather and climate satellite missions must consider a range of architectural trades to meet observing requirements. Frequently, fundamental decisions such as the number of observatories, the instruments manifested, and orbit parameters are determined based upon assumptions about the characteristic temporal and spatial scales of variability of the target observation. With the introduced methodology, representativity errors due to separations in space and time can be quantified without prior knowledge of instrument performance, and errors driven by constellation design can be estimated without model ingest or analysis.