Analysis Ready Data .

Background . LSI-VC was tasked to progress ARD “Define intercomparable Analysis-Ready Data (ARD) products within the context of land surface imaging”

Process and progress . Plenary assigns action : 2015-11 Plenary, Kyoto LSI-VC-1, Frascati : 2016-02 Initial Draft : 2016-03, Canberra SEO initiate; input from many Final Daft : 2016-07, LAX A few open questions / clarifications / suggestions Present to SIT : 2016-07, email + Draft CEOS resolution SIT discussion : 2016-09, Oxford Plenary consideration : 2016-11, Brisbane

Working Definition of ARD . Analysis Ready Data (ARD) are satellite data that have been processed to a minimum set of requirements and organized into a form that allows immediate analysis without additional user effort

ARD needs and benefits . Ensure users have access to data that they can ‘just use’ as an input for their specific use: confident that it is consistent, comparable, and representative of the ‘real world’. Input for users is a measurement of the Earth, not pictures from a satellite. Currently, the data provided to users stops several steps earlier, requiring them to independently undertake complex pre-processing steps before they can even start to do what they want: extract information

ARD needs and benefits . Land surface applications need: Measurements that can be compared differences are due to the target changing, not the observation process Known location – ‘Stackable through time’ Metadata – ‘I trust the source of these measurements, and I think this observation is okay to use’

Measurements . Comparable measurements are fundamental to science, e.g., Temperature – degrees Wind speed – m/s Sea level – meters Measuring conditions are controlled Direct sun; wind obstructions; land subsidence Different instruments are used Where, and when are known!

Measurements . The Definition says: Ideally, ARD will provide geophysical quantities such as surface reflectance, temperature, or backscatter amplitude facilitating the use of observations from multiple platforms and sensors. An example is normalised land surface reflectance

Known location – stackability . Don’t move the weather station! The definition says: Geometric Calibration – Establishing ground position, taking into account terrain and ground control points and assessing position accuracy. Geometric calibration allows products to be used with other spatial data, and in particular to be ‘stacked as time- series’. Grid projection choices do not impact minimum ARD requirements. Adjustments for ground variability typically use a Digital Elevation Model (DEM).

Metadata – informing the user . Where did the measurement come from? Should you trust it? How was it made? General Metadata – Dataset and pixel descriptive information that establish the lineage of the product and provide confidence to the user that it is authoritative, by detailing the steps taken to produce the data in its current state. This includes: satellite, instrument, acquisition date and time, spatial boundaries, pixel locations, mode, processing details, and grid projection

Metadata – informing the user . Is the actual measurement okay? Accuracy? Quality Metadata -Dataset and pixel descriptive information such as quality flags which allow users to make informed decisions about the suitability of the products for a particular use. For example clouds, land type, missing data, saturation and accuracy assessments.

ARD removes a barrier to use .

ARD removes a barrier to use .

Some points of discussion . Data Policy – can data be ‘analysis ready’ if not free and open?(JAXA) Data policy is a different potential barrier to use The definition is silent on this question No change needed

Some points of discussion . Is RADAR data in or out? Is it in scope? Radar data are a crucial element of land surface imaging Is there agreement on the main concepts? Yes - (e.g. JAXA, CSIRO, CATAPULT, …) However, interferometric analyses are a separate processing chain. ARD will not ‘help’ that.

Some points of discussion . Is RADAR data in or out? "Analysis Ready Data (ARD) for SAR refers to spatially and temporally registered backscattering coefficients.  These data, together with associated Local Incidence Angle (LIA) and layover/shadow maps should be provided in the data cube.  The definition and processing steps should satisfy 80% of SAR users."

Some points of discussion .

Some points of discussion . USGS / GA - Would prefer a more generic definition “Geophysical measurements that are comparable in space and time with sufficient per-pixel (observation) metadata to enable users to select ‘observations of interest’ as input into their analyses.”

Some points of discussion . USGS / GA - there should be room for improvement in the specifications for ARD data, e.g.: Target, Threshold, & Breakthrough specifications A minor change of wording caters for this: data products (e.g. composites, indices or additional corrections) that meet or exceed these minimum requirements would also be considered ARD

Some points of discussion . Differing views on the need for a definition CSA ARD not helpful for interferometry (but MSSR) RCA will explore ARD specifications to allow users avoid pre-processing steps ESA “Data exploitations platforms” => no need CSIRO, SEO, GA see a clear need Others – ARD ‘resonates’ USGS – CEOS Chair 2017 - CEOS strategy for ARD

Process and progress . Plenary assigns action : 2015-11 Plenary, Kyoto LSI-VC-1, Frascati : 2016-02 Initial Draft : 2016-03, Canberra SEO initiate; input from many Final Daft : 2016-07, LAX A few open questions / clarifications / suggestions Present to SIT : 2016-07, email Draft CEOS resolution SIT discussion : 2016-09, Oxford Plenary consideration : 2016-11, Brisbane

Progress and next steps . Note the work of the Land Surface Imaging Virtual Constellation, working with …, in progressing it’s work plan as indicated in the 2015 Plenary (Kyoto) to produce a high level definition of Analysis Ready Data. Adopt and endorse the high level definition of Analysis Ready Data presented by LSI-VC, and the accompanying detail that further clarifies the concept. Initiate further work through the appropriate CEOS instruments to develop a CEOS strategy in relation to Analysis Ready Data to ensure that …. https://docs.google.com/document/d/181mFoYt1K1yhLhb6BMwtuGZkAYTeHsWIhvQJn4y0-lE/edit?usp=sharing