Fiducial Reference Measurement
Concept
2nd EarthCARE Cal/Val Workshop
25 May 2021

Jonas v. Bismarck, Philippe Goryl
Issue/Revision: 0.0
Reference:
Status:ESA UNCLASSIFIED - For Official Use

FIDUCIAL
fi·du·cial (adj) Regarded or employed as a standard ofreference, as in surveying.
[Late Latin fdcilis, from Latin fdcia, trust, from fdere, to trust; seebheidhin Indo-European roots.]•Cal/Val activities are a key component of a satellite mission, giving credibility to the mission data. For ESA’s
EO mission they usually are a complementary effort of:•
ESA and ESL/DISC/MPC expert teams•
Independent validation teams and ESA campaigns••

FRMs (Fiducial Reference Measurements)

Maintaining quality is all about a regular stream of verification and validation data that can be used to checkmission and product performance. Optimally:•Validate satellites with standard data that we can be trusted à FIDUCIAL•

fundamental traceability and uncertainty budgets for ground measurements used

Slide 2

FRM: definitions and scope

Fiducial Reference Measurements (FRM)“Fiducial Reference Measurements (FRM) are a suite ofindependent, fully characterized, and traceable groundmeasurements that follow the guidelines outlined by the GEO/CEOS
Quality Assurance framework for Earth Observation (QA4EO). These
FRM provide the maximum Return On Investment (ROI) for asatellite mission by delivering, to users, the required confidence indata products, in the form of independent validation results andsatellite measurement uncertainty estimation, over the entire endto-end duration of a satellite mission..”->In short: FRMs are tailored and fully characterizedmeasurements in support of satellite Cal/Val, directly
mimicking the satellite sensor measurements when possible.
«FRM4» projects : preparatory R&D activities
Slide 3

FRM: definitions and scope

Fiducial Reference Measurements (FRM)
The defining characteristics for FRM are:
• FRM measurements should ideally have documented SI traceability using metrology
standards and/or community recognised best practices;• FRM measurements are independent from the satellite geophysical retrieval process;• An uncertainty budget for all FRM instruments, and derived measurements, isavailable and maintained;• FRM measurement protocols, procedures and community-wide management practices(measurement, processing, archive, documents, etc.) are defined, published andadhered to by FRM instrument deployments;• FRM are accessible to other researchers allowing independent verification of processingsystems;• FRM are required to determine the in-orbit uncertainty characteristics of satellite
geophysical measurements via independent validation activities.
Slide 4

Selection of FRM4 and FRM Projects run by the ESA SPPA team:
http://frm4ghg.aeronomie.be/

The focus of the “FRM Ground-Based FTIR Greenhouse Gas Observations” (FRM4GHG)
project is the intercomparison of instruments and harmonization of products andretrievals from ground based FTIR systems à Greenhouse Gas. New project starting
2021, 4 years duration.

http://frm4doas.aeronomie.be/

The “FRM for Ground-Based DOAS Air-Quality Observations” project aims at theharmonization of the retrievals from UV-Visible ground based spectrometers (MAXDOASor Pandora) -> the standards of FRMs for NO2 and ozone. New project starting 2021, 4years duration.

FRM4SARBest practice for deploying an a site (and analysis) for accurate geometric calibration.

FRM4RADAR -> see following
presentation

Mini observation network for validation/ verification of cloud profile measurements fromspace (EarthCARE CPR L2A etc) integrated and fully compatible with ACTRIS-Cloudnet

https://www.pandoniaglobal-network.org/

PGN is a joint ESA-NASA ground-based remote sensing network for trace gases andatm composition. The main instrument of Pandonia is the Pandora-1S/2S system.

FRM4VEG https://frm4veg.org/

Protocols for traceable in-situ measurements of vegetation-related parameters, tosupport the validation of Copernicus products from Sentinel-2, -3, and PROBA-V andoptical Sensor TPMs. Characterisation of Sites.

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FRM: Conclusions• Fiducial Reference Measurements (FRM) are tailored and fully characterized measurements
in support for satellite Cal/Val, and may be considered a sub-set of ‘in-situ’ measurements.
• They are a prioritized suite of measurements to demonstrate that mission products meet themission’s requirements.
• The FRM are essential for the validation of satellite measured parameters, in particular for
missions aiming to respond to long-term public needs (e.g. Sentinel missions, meteorologicalmissions).
• The FRM shall meet specific mission requirements in terms of accuracy and traceability

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