FINAL ATTACHMENT B PORD.pdf

Effective Date: August 22, 2023 418-XO-OCXPORD-0119 Responsible Organization: GeoXO Flight Project/Code 418 Baseline Version 1.0

To verify the correct version of this document, please contact the GeoXO Series Configuration Management Office.

Geostationary Extended Observations (GeoXO) Ocean Color (OCX)

Performance and Operational Requirements Document (PORD) Signature page

Prepared by:

Email approval by: 08/22/2023

Michael Otero Date GeoXO Flight Project, Instrument Systems Engineer NASA GSFC, Code 418

Reviewed by:

Electronically approved by: 08/01/2023

Kevin J. Tewey Date GeoXO Flight Project, Instrument Manager

Approved by:

Electronically approved by: 08/21/2023

Steven W. Bidwell Date GeoXO Flight Project, Mission Systems Engineer

Electronically approved by: 08/21/2023

Sergey Krimchansky Date GeoXO Flight Project, Instrument Systems Manager

Effective Date: August 22, 2023 418-XO-OCXPORD-0119 Responsible Organization: GeoXO Flight Project/Code 418 Baseline Version 1.0

To verify the correct version of this document, please contact the GeoXO Series Configuration Management Office.

Approved by:

Electronically approved by: 08/22/2023

Monica Todirita Date GeoXO Flight Project, Deputy Project Manager NOAA GSFC, Code 418

/GeoXO Flight Project OCX

OCXPORD

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and Operational Requirements Document (PORD)

Version: 1.0 Printed by: hlhedger Printed on: Wednesday, August 23, 2023

No filter applied.

No sort applied.

Generated from DOORS 9.7.2.4

Contents

1 1Scope

1.1 1Identification

1.2 1Mission Review

1.3 1Document Overview

1.4 1Terminology

1.5 2Definitions

1.6 4Requirement Applicability

2 5Documents

2.1 5Applicable Documents

2.2 5Reference Documents

3 6Sensor Requirements

3.1 6Sensor Definition

3.1.1 6OCX Modes

3.1.1.1 6Safe Mode

3.1.1.2 7Normal Operational Mode

3.1.1.3 7Diagnostic Mode

3.1.1.4 8Outgassing

3.1.2 8On-Orbit Operations

3.1.2.1 8Operational Zones

3.1.2.1.1 8Performance Zone

3.1.2.2 8Imaging the Sun

3.1.2.3 8Operations After Maneuvers

3.1.2.3.1 8Yaw Flip

3.1.2.3.2 9Stationkeeping

3.1.2.3.3 9Post Storage Activation

3.1.2.4 9Detector Operating Temperatures

3.2 9Normal Operational Mode Sensor Requirements

3.2.1 9Coverage

3.2.1.1 9Coverage Rate

3.2.1.2 10Flexible and Efficient Imaging Pattern

3.2.1.3 11Field of Regard

3.2.1.4 11Simultaneity

3.2.1.5 11Data Latency

Project: GeoXO Flight Project OCX Module: OCXPORD Baseline Version: 1.0

Contents ii

3.2.2 11Channel Definitions, SNR, Dynamic Range

3.2.2.1 11Baseline

3.2.2.2 12System Spectral Response

3.2.2.2.1 12Spectral Response Envelope

3.2.2.2.2 13Within Channel Spectral Response Uniformity

3.2.2.2.3 13Channel Center Wavelength Knowledge

3.2.3 13Spatial Resolution and Sampling

3.2.3.1 13System Modulation Transfer Function

3.2.3.2 14Spatial Response Uniformity

3.2.3.3 14Ringing from a Sharp Edge

3.2.4 14Image Navigation and Registration

3.2.4.1 14Star Sensing

3.2.4.2 14INR Performance Requirements

3.2.4.2.1 15Navigation

3.2.4.2.2 15Frame-to-Frame Registration

3.2.4.2.3 15Within Frame Registration

3.2.4.2.4 15Channel-to-Channel Registration

3.2.5 15Radiometric Accuracy and Precision

3.2.5.1 15Repeatability

3.2.5.1.1 15Pixel-to-Pixel

3.2.5.2 16Coherent Noise

3.2.5.3 16Calibration of Channels

3.2.5.4 17Spatial Uniformity of Data

3.2.5.5 17Crosstalk

3.2.5.5.1 17Channel-to-Channel

3.2.5.5.2 18Within Channel

3.2.5.6 18Blooming

3.2.5.7 18Quantization Step Size

3.2.5.8 18Polarization

3.2.5.8.1 18Polarization Control

3.2.6 18System Linearity

3.2.7 19Data Compression

3.2.7.1 19Lossless Data Compression

3.2.7.2 19Lossy Compression

3.3 19Visualization Algorithm

4 20Design Requirements

4.1 20Reliability

4.2 20Redundancy

Contents iii

4.2.1 20Redundant Component Selectabiltiy

4.2.2 20Interchangability of Flight Model Units

4.2.3 20Reserved

4.3 20Mechanical Requirements

4.3.1 20Design Limit Loads

4.3.2 21Yield Strength

4.3.3 21Ultimate Strength

4.3.4 22Unit Stiffness

4.3.5 22Critical Members Design Values

4.3.6 22Redundant Members Design Values

4.3.7 22Selective Design Values

4.3.8 22Fracture Control

4.3.9 23Mechanisms

4.3.10 24Pressurized Units

4.3.11 24Alignment Reference

4.3.12 24Precision Component Assembly

4.4 24Thermal Requirements

4.4.1 24Mission Allowable Temperatures

4.4.2 25Thermal Gradients

4.4.3 25Non-Operational Temperatures

4.4.4 25Thermal Control Hardware

4.4.5 25Detector Cooling Margin

4.4.6 26Radiator

4.4.7 26Heat Pipe (Two-phase Heat Transfer Device)

4.5 26Power Requirements

4.5.1 26Power Regulators and Supplies

4.5.2 26Fuses

4.5.3 27Covers for test Connectors

4.5.4 27Keyed Connectors

4.6 27Onboard Processors Requirements

4.6.1 27Flight Load Non-Volatile Memory

4.6.2 27Commandable Reinitialization

4.6.3 27Deterministic Power-on Configuration

4.6.4 27Fail-safe Recovery Mode

4.7 27Flight Software Requirements

4.7.1 27Language and Methodology

4.7.2 27Flight Software Upload

4.7.3 28Flexibility and Ease of Software Modification

Contents iv

4.7.4 28Version Identifiers

4.7.5 28Flight Processor Resource Sizing

4.7.6 29Software Event Logging

4.7.7 29Warm Restart

4.7.7.1 29Processor Re-Start

4.7.7.2 29Autonomous Re-Start

4.7.8 29Memory Integrity

4.7.8.1 29Memory Verification

4.7.8.2 29Bit Error Detection and Correction

4.7.9 29Memory Dump

4.7.10 30Telemetry Cadence and Dwell Control

4.7.11 30Long-Duration Test

4.7.12 30Unnecessary and Unreachable Software

5 31Ground Support Equipment and Development

5.1 31Electrical System Test Equipment

5.2 31Flight Software Development Environment

5.3 31Ground Processing Demonstration System

5.4 32FM and GSE Shipping Containers

6 33OCX Simulators

6.1 33OCX Instrument Hardware Simulator (OCX-IHS)

6.2 33OCX Instrument Software Simulator (OCX-ISS)

7 35FM Design Verification Requirements

7.1 35Powered-on Operating Time and Trouble-Free Performance Testing

7.2 35Structural and Mechanical Verification Requirements

7.2.1 35Mechanical Test Factors and Duration

7.2.2 38Minimum Workmanship

7.2.3 39Testing in Flight Configuration

7.2.4 39Structural Proof Testing

7.2.5 39Modal Survey Characterization

7.2.6 39Structural Qualification

7.2.7 39Deployment and Articulation Verification

7.2.8 40Life Test

7.2.9 40Mechanical Clearance Verification

7.3 40Electromagnetic Compatibility Verification

7.3.1 40General

7.3.2 40Electrostatic Arc-Discharge Susceptibility

Contents v

7.3.2.1 40External Surface-to-Surface direct discharge

7.3.2.2 40Deep Dielectric Charging

7.3.2.3 40ESD Characteristics

7.4 41Thermal Test Requirements

7.4.1 41General

7.4.1.1 41Thermal Test Chronology

7.4.1.2 42Pressure

7.4.2 42Thermal Vacuum

7.4.2.1 42Transition Rates

7.4.2.2 42Corona Operation

7.4.2.3 42Hot and Cold Start Demonstrations

7.4.2.4 42Heater Verification

7.4.2.5 43Flight Temperature Sensor Verification

7.4.3 43TV Thermal Cycling

7.4.3.1 43Cumulative Cycles

7.4.3.2 43Ambient Pressure Thermal Cycling Substitution

7.4.3.3 43Qualification, Protoflight and Acceptance Temperatures

7.4.3.4 44Survival Heater Verification

7.4.3.5 44Temperature test tolerances

7.4.3.6 44Plateau Criteria

7.4.4 45Thermal Balance (TB)

7.4.4.1 45Balance Points

7.4.4.2 45Instrument Configuration

7.4.4.3 45Accuracy and Knowledge

7.4.4.4 45Steady State Criteria

7.5 46Test Condition Tolerances

8 48Acronyms

Contents vi

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ID

OCXPORD1

OCXPORD2

OCXPORD3

OCXPORD4

OCXPORD5

OCXPORD6

OCXPORD7

OCXPORD8

OCXPORD9

OCXPORD10

OCXPORD11

OCXPORD12

OCXPORD13

OCXPORD14

OCXPORD15

Object Number

1.1

1.1.0-1

1.2

1.2.0-1

1.2.0-2

1.2.0-3

1.2.0-4

1.3

1.3.0-1

1.4

1.4.0-1

1.4.0-2

1.4.0-3

1.4.0-4

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

1 Scope

1.1 Identification

This Performance and Operational Requirements Document (PORD) sets forth the performance requirements for the National Oceanic and Atmospheric Administration (NOAA) Geostationary eXtended Orbits (GeoXO) Ocean Color (OCX) instrument.

1.2 Mission Review

The OCX is a multi-channel, UltraViolet (UV) through infrared, passive imaging radiometer used to measure environmental data as part of a 3-axis stabilized, geostationary weather satellite system. The OCX remotely collects imagery of the Earth’s coastal waters for harmful algal blooms, water turbidity, and general water quality, fisheries management, habitat quality/assessment/mapping, pollution tracking, biogeochemical processing in coastal regions, warnings and predictions.

The OCX objectives are as follows:

a) Provide new NOAA ocean color operational data that will be used by NOAA and other public and private agencies to produce forecasts of water quality pollution including turbidity and harmful algal blooms.

b) Provide ocean color operational data that will be used to expand knowledge of coastal waters and ocean processes in the exclusive economic zone (EEZ).

The OCX provides data to the Ground System via the spacecraft communication system. The Ground System takes the OCX data, spacecraft telemetry data, orbit determination data and other required information and autonomously generates radiometrically calibrated and navigated data (Level 1b data) for the NOAA users.

The Ground System procured by the Government will implement algorithms developed by the OCX Contractor to satisfy performance requirements. The Ground System will calibrate and navigate the data to generate Level 1b data.

1.3 Document Overview

This document contains all performance requirements for the OCX instrument and Ground Support Equipment (GSE). This document, the General Interface Requirements Document (GIRD), and the OCX Unique Instrument Interface Document (UIID) define all instrument to spacecraft interfaces for the OCX instrument.

1.4 Terminology

The use of “shall” designates a requirement that must be met.

The use of “will” designates a statement of fact or intention of the Government.

The use of “may” designates that permission has been granted by the Government.

The term “TBD” means, “to be determined” and is used when no value is available with subsequent study needed to obtain it.

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ID

OCXPORD16

OCXPORD17

OCXPORD18

OCXPORD19

OCXPORD20

OCXPORD21

OCXPORD22

OCXPORD23

OCXPORD27

OCXPORD28

OCXPORD24

Object Number

1.4.0-5

1.5

1.5.0-1

1.5.0-2

1.5.0-3

1.5.0-4

1.5.0-5

1.5.0-6

1.5.0-7

1.5.0-8

1.5.0-9

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

The term “TBR” means “to be refined/reviewed” for a value that is subject to review for appropriateness and is subject to revision. The Contractor is liable for compliance with the information marked “TBR” as if the “TBR” notation did not exist.

1.5 Definitions

Throughout this document, the following definitions apply:

Accuracy: Refers to the error in a measurement, that is the difference between the measurement result and the object to be measured (the measured or true value). It includes both systematic and random errors. Systematic errors must be estimated from an analysis of the experimental conditions and techniques. Random errors can be determined, and reduced, through repeated measurements under identical conditions.

Albedo: Refers to the fraction of the solar spectrum taken from the default MODTRAN solar irradiance file, version 4V1R1 (newkur.dat) that is reflected by the Earth at the top of the atmosphere assuming a Lambertian surface (see Ocean Color (OCX) Radiances Upwelling Document, document number 418-XO-RPT-0077, for values).

All requirements/all performance requirements/all operational requirements: Refers to any performance characteristic or requirement in the OCX PORD, OCX UIID, and the

GIRD.

Credible Failure: A failure condition that has a reasonable likelihood of occurrence over the mission life. With consideration of reliability analysis and engineering experience, the Government technical authority will determine credibility of failure. For the purposes of this document, failures of structure, pressure vessels, and pressurized lines and fittings are not considered credible failure modes if those elements comply with the applicable requirements of this document.

Derived Noise Equivalent Delta Radiance (NEDN): Refers to the NEDN required to meet the Noise Equivalent Delta Temperature (NEDT) specification or Signal-to-Noise Ratio (SNR) specification.

Detector sample or element: Refers to the output of a physical detector after the Analog-to-Digital (A/D) converter and Time Delay and Integration (TDI) processing, if applicable.

Eclipse: Defined as when the solar disk is completely occulted by the Earth or Moon, as viewed from the satellite.

EEZ East Region: Any spatial resolution element in the Atlantic along the US East or Gulf Coast including the Gulf of Mexico and within 400 km from the continental US shoreline, with inclusion of Puerto Rico in the Caribbean. This is a region of approximately 6110 km x 400 km in area without including Puerto Rico and 6300 km by 400 km including Puerto Rico EEZ.

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ID

OCXPORD25

OCXPORD29

OCXPORD31

OCXPORD30

OCXPORD26

OCXPORD35

OCXPORD32

OCXPORD221

Object Number

1.5.0-10

1.5.0-11

1.5.0-12

1.5.0-13

1.5.0-14

1.5.0-15

1.5.0-16

1.5.0-17

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

EEZ West Region: Any spatial resolution element in the Pacific along the US West coast and within 400 km from the continental US shore plus any spatial resolution element in the Pacific along the Hawaii coast and within 400 km from the Hawaiian shore, plus approximately 2000 km of the observable southern Alaska coast from the GOES West slot (137 West) that falls within 400 km from the Alaskan shore. This is a region of approximately 3600 km by 400 km in area plus 2000 km by 400 km in area for Alaska totaling 5600 km by 400 km in area.

Fixed-Grid Angles: Refers to North/South (NS) and East/West (EW) Euler angles defined as follows. Starting with the orbit reference frame (ORF) in GIRD62 at the ideal satellite location, a positive NS angle is a rotation of the ORF about its +x axis, and a positive EW angle is a subsequent rotation of the rotated frame about its +y axis. The +z axis of the final frame is the line of sight (LOS) represented by the EW and NS fixed-grid angles.

Frame: Collection of pixels from a contiguous region as commanded by a minimum bounding rectangle.

Fully Functional Configuration: Being able to perform the following functions: scene radiance measurement, radiometric calibration, star sensing, on-orbit monitoring of calibration sources and instrument response changes, acquisition of sensor health and status data, generation of sensor, calibration, monitoring, health and status data streams, and reception and execution of command and control data.

Great Lakes: Any spatial resolution element in the Great Lakes. This is a region of approximately 900 km by 1250 km in area.

Launch: The period of time between lift off and the separation of the satellite from the launch vehicle.

Level 0 data: Raw data reconstructed to unprocessed instrument data at full space-time resolution with all available supplemental information to be used in subsequent processing (e.g., ephemeris, health and safety) appended.

Level 1a data: Unpacked and reformatted Level 0 data with all supplemental information to be used in subsequent processing appended. Data generally presented as full space/time resolution. A wide variety of sub-level products are possible. Note:

For OCX, data are not resampled.

Level 1b data: Unpacked and reformatted Level 0 data with all supplemental information to be used in subsequent processing appended. Radiometric calibration and navigation are applied to produce parameters in physical units. Data generally presented as full space/time resolution. Note: For OCX, data are not resampled.

Level 2+ data: Retrieved environmental variables (e.g., sea surface temperature) and higher products.

Mission Allowable Temperatures (MAT): Mission Allowable Temperatures are the established range of temperatures that instrument units are permitted to experience while operating in orbit. MAT are established based upon analytical temperature predictions with appropriate margin based on the state of the thermal design. MAT encompasses worst-case operating temperature predictions, uncertainty, and any Contractor desired temperature margin.

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ID

OCXPORD33

OCXPORD36

OCXPORD218

OCXPORD37

OCXPORD38

OCXPORD39

OCXPORD34

OCXPORD40

OCXPORD41

OCXPORD42

OCXPORD43

OCXPORD44

OCXPORD45

Object Number

1.5.0-18

1.5.0-19

1.5.0-20

1.5.0-21

1.5.0-22

1.5.0-23

1.5.0-24

1.5.0-25

1.5.0-26

1.5.0-27

1.6

1.6.0-1

1.6.0-2

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

Navigation: Refers to the determination of the location of each pixel relative to a fixed reference, namely for the OCX, the GRS80 geoid viewed from the idealized geostationary position, with latitude and longitude information appended in the Level 1b product.

Navigation Error: Refers to the angular error of locations in the fixed-grid angles.

Non-operational Temperatures (NOT): Non-operational Temperatures are the established range of temperatures that instrument units are permitted to experience while not operating and not powered. NOT represent the permissible range while the hardware is powered off. Survival heaters maintain hardware at or above the cold NOT limits and passive design maintains hardware below the upper NOT limits. NOT are also known as non-operating MAT.

Pixel: All spectral channels associated with a given spatial resolution element after processing, including calibration and navigation (Level 1b).

Polarization Sensitivity: Defined as the ratio of the difference between maximum and minimum output to the sum of the maximum and minimum output obtained when the plane of incoming 100% linearly polarized radiation is rotated through 180 degrees.

Precision: Refers to the standard deviation of a statistically meaningful number of samples of a measurement.

Registration: Refers to maintaining the spatial relationship between pixels within frames, between frames, and between channels.

SNR: Signal-to-Noise Ratio.

Transfer Orbit: The sequence of events that transpires to establish the GeoXO satellite on-station after the GeoXO satellite has separated from the launch vehicle.

Unit: A functional subdivision of a subsystem and generally a self-contained combination of items performing a function necessary for the subsystem's operation.

Examples are electronics unit and sensor unit.

1.6 Requirement Applicability

The requirements in this OCX PORD pertain to the OCX ‘system’, which may include motors, optics, detectors, signal processing electronics and software, and ground processing. The OCX Contractor is not responsible for the whole Ground System, but certain specifications may require some level of ground processing after collection but before data distribution, i.e., decompression, re-sampling, and calibration.

All requirements apply over the entire life of the OCX. Requirements, such as Modulation Transfer Function (MTF) and Image Navigation and Registration (INR), apply after including Level 1b ground processing impacts, except as indicated.

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ID

OCXPORD46

OCXPORD47

OCXPORD48

OCXPORD49

OCXPORD50

Object Number

2.1

2.1.0-1

2.2

2.2.0-1

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

2 Documents

2.1 Applicable Documents

The following form a part of this specification to the extent specified herein.

1. CCSDS Recommendation for Space Data System Standards, Image Data Compression, CCSDS 122.0-B-2, September 2017.

2. CCSDS Recommendation for Space Data System Standards, Low- Complexity Lossless and Near-Lossless Multispectral and Hyperspectral Image Compression, CCSDS 123.0-B-2, February 2019.

3. Structural Design and Test Factors of Safety for Spaceflight Hardware, NASA, Document Number NASA-STD-5001B, August 6, 2014

4. General Environmental Verification Specification for GSFC Flight Programs and Projects, Document Number GSFC-STD-7000B, April 28, 2021

5. NASA Payload Safety Requirements NASA-STD-8719.24A, March 30, 2022, with NASA-STD-8719.24-ANNEX Rev B, May 22, 2023

6. Geostationary eXtended Observations (GeoXO) Ocean Color (OCX) Radiances Upwelling Document, 418-XO-RPT-0077

2.2 Reference Documents

The following are reference documents.

1. Report Concerning Space Data System Standards: LOSSLESS

MULTISPECTRAL AND HYPERSPECTRAL IMAGE COMPRESSION,

Informational Report CCSDS 120.2-G-2, GREEN BOOK, December 2022.

2. Recommendation for Space Data System Standards: SPECTRAL

PREPROCESSING TRANSFORM FOR MULTISPECTRAL AND

HYPERSPECTRAL IMAGE COMPRESSION” Recommended Standard CCSDS 122.1-B-1, BLUE BOOK, September 2017.

3. Moving Mechanical Assemblies for Space and Launch Vehicles, AIAA S-114A-2020, Jan. 14, 2021.

4. General Specification for Assemblies, Moving Mechanical, for Space and Launch Vehicles, Document Number MIL-A-83577B, February 1, 1988.

5. Space Mechanisms Handbook, Document Number NASA TP-1999-206988, March 1, 2002.

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OCXPORD52

OCXPORD53

OCXPORD54

OCXPORD55

OCXPORD56

OCXPORD57

OCXPORD58

OCXPORD59

OCXPORD60

OCXPORD61

OCXPORD62

Object Number

3.1

3.1.1

3.1.1.0-1

3.1.1.0-2

3.1.1.0-3

3.1.1.0-4

3.1.1.0-5

3.1.1.0-6

3.1.1.1

3.1.1.1.0-1

3.1.1.1.0-2

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

3 Sensor Requirements

3.1 Sensor Definition

3.1.1 OCX Modes

The OCX shall execute commands to individually enable and disable each autonomous function.

Rationale: Autonomous capability needs to be able to be disengaged as well.

The OCX shall initiate all commanded mode transitions in no more than 20 seconds after receipt of command.

Rationale: Mode transitions should occur rapidly for operators.

The OCX shall make limits and triggers of autonomous functions changeable by command.

Rationale: Autonomous functions should be controlled by operators if there is a special need to do so.

The OCX shall transition from its current mode to any other mode without causing permanent damage to itself.

Rationale: Mode transitions should occur without damage.

The OCX shall indicate the mode of the instrument in housekeeping telemetry.

Rationale: Knowledge of instrument modes is needed for data processing.

The OCX shall provide command and housekeeping telemetry functions in all powered modes.

Rationale: Command and housekeeping telemetry is necessary for monitoring instrument health at all times.

3.1.1.1 Safe Mode

The OCX shall implement a Safe Mode.

Rationale: The OCX needs a Safe Mode to enable straightforward storage.

The OCX shall be in a thermally, electrically, and optically safe configuration for an indefinite period of time while in Safe Mode.

Rationale: Safe Mode of instrument enables a thermally and optically safe configuration for storage.

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ID

OCXPORD63

OCXPORD64

OCXPORD65

OCXPORD66

OCXPORD67

OCXPORD68

OCXPORD219

OCXPORD220

OCXPORD69

OCXPORD70

OCXPORD71

OCXPORD72

Object Number

3.1.1.1.0-3

3.1.1.2

3.1.1.2.0-1

3.1.1.2.0-2

3.1.1.3

3.1.1.3.0-1

3.1.1.3.0-2

3.1.1.3.0-3

3.1.1.3.0-4

3.1.1.3.0-5

3.1.1.3.0-6

3.1.1.3.0-7

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

The OCX shall enter Safe Mode upon receipt of a ground command, receipt of an autonomous safe mode command from the observatory, or detection of internal faults capable of causing permanent damage to the instrument.

Rationale: The OCX needs to employ the Safe Mode after fault detection to ensure that there is time for recovery.

3.1.1.2 Normal Operational Mode

The OCX shall be in a fully functional configuration while in Normal Operational Mode.

Rationale: Normal mode is used for observations that require full functionality.

The OCX shall meet all performance requirements while in Normal Operational Mode without receiving commands or data loads for a minimum of 7 days.

Rationale: Autonomy is required for a period of 7 days, without impacting performance.

3.1.1.3 Diagnostic Mode

The OCX shall implement a Diagnostic Mode.

Rationale: Diagnostic mode is needed for diagnosing anomalies.

The OCX shall enter Diagnostic Mode only on command.

The OCX data transmission rate in Diagnostic Mode shall comply with the allocation in the OCX UIID.

The OCX shall be in a fully functional configuration while in Diagnostic Mode.

Rationale: Diagnostic mode must be fully functional.

The OCX shall by command send telemetry for selected channels while in Instrument Diagnostic Mode.

Rationale: Diagnostic mode will afford commandable channel engagement for diagnosing anomalies.

The OCX shall by command send the individual measurement in those cases where Time Delay Integration (TDI) data is digitally processed off the focal plane while in Diagnostic Mode.

Rationale: Diagnostic mode will send data from TDI if employed to help in validation and in assessing anomalies.

The OCX shall by command send data from all detectors while in Diagnostic Mode.

Rationale: Diagnostic mode will send data from all detectors to help in validation and in assessing anomalies.

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ID

OCXPORD73

OCXPORD74

OCXPORD75

OCXPORD76

OCXPORD77

OCXPORD78

OCXPORD80

OCXPORD81

OCXPORD82

OCXPORD84

OCXPORD86

OCXPORD87

OCXPORD90

OCXPORD91

Object Number

3.1.1.3.0-8

3.1.1.3.0-9

3.1.1.3.0-10

3.1.1.3.0-11

3.1.1.4

3.1.1.4.0-1

3.1.2

3.1.2.1

3.1.2.1.1

3.1.2.1.1.0-1

3.1.2.2

3.1.2.2.0-1

3.1.2.3

3.1.2.3.1

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

The OCX shall by command send the same data both compressed and uncompressed if the data is capable of being compressed while in Diagnostic Mode.

Rationale: Diagnostic mode will send compressed and uncompressed to help in validation and in assessing anomalies

The OCX shall by command send all bits from the A to D converter while in Diagnostic Mode.

Rationale: Diagnostic mode will send all bits to help in validation and in assessing anomalies.

The OCX shall by command perform electronic in-flight calibration.

Rationale: Diagnostic mode electronic in-flight calibration will help in validation and in assessing anomalies.

The OCX shall by command send dwell data (increased samples per second of a particular telemetry measurand) while in Diagnostic Mode.

Rationale: Diagnostic mode dwell data will help in validation and in assessing anomalies.

3.1.1.4 Outgassing

The post-launch outgas period shall be no longer than 14 days.

Rationale: The OCX will sublimate and evaporate contaminants from hardware to prevent contamination from jeopardizing performance.

3.1.2 On-Orbit Operations

3.1.2.1 Operational Zones

3.1.2.1.1 Performance Zone

The OCX shall meet all performance requirements for all pixels whose solar zenith angle (SZA) is less than 70 degrees.

Rationale: SNR, on-orbit calibration, and accuracy are met in well-illuminated conditions during the day and may degrade in performance outside this region. Solar zenith angle is the angle measured off local zenith to the moving sun’s position.

3.1.2.2 Imaging the Sun

The OCX shall survive the presence of the sun within the field of regard without sustaining any permanent degradation in performance.

Rationale: The sun must not result in damage to the instrument.

3.1.2.3 Operations After Maneuvers

3.1.2.3.1 Yaw Flip

Page 9 of 48 Printed Wednesday, August 23, 2023

ID

OCXPORD92

OCXPORD93

OCXPORD94

OCXPORD95

OCXPORD96

OCXPORD97

OCXPORD98

OCXPORD99

OCXPORD100

OCXPORD101

OCXPORD102

OCXPORD103

OCXPORD104

Object Number

3.1.2.3.1.0-1

3.1.2.3.2

3.1.2.3.2.0-1

3.1.2.3.3

3.1.2.3.3.0-1

3.1.2.4

3.1.2.4.0-1

3.1.2.4.0-2

3.2

3.2.1

3.2.1.1

3.2.1.1.0-1

3.2.1.1.0-2

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

The OCX shall meet all radiometric, coverage and INR requirements within 30 minutes after the spacecraft interface has returned to being within specification following a yaw flip.

Rationale: If the spacecraft executes a yaw flip, the instrument recovery will occur in this duration after the interface is restored to nominal conditions.

3.1.2.3.2 Stationkeeping

With the exception of a yaw flip, the OCX shall meet all radiometric, coverage and INR requirements within 2 minutes after the spacecraft interface has returned to being within specification following spacecraft maneuvers.

Rationale: If the spacecraft executes a different maneuver than a yaw flip, the instrument recovery will occur in this short duration after the interface is restored to nominal conditions.

3.1.2.3.3 Post Storage Activation

The OCX shall meet all requirements within 4 days of turn on after post storage activation.

3.1.2.4 Detector Operating Temperatures

The OCX detector set-point temperature shall be selectable by command to ensure radiometric performance during degradation at end of life.

Rationale: This provides for set point temperature adjustments near the operating temperature range that may be needed due to gain changes or troubleshooting.

The OCX detector temperatures shall be included in telemetry to support radiometric performance assessment.

Rationale: OCX may be thermally sensitive due to its detectors and thermal telemetry will provide information for potential corrections and troubleshooting.

3.2 Normal Operational Mode Sensor Requirements

3.2.1 Coverage

3.2.1.1 Coverage Rate

Note that these coverage requirements define a capability and not a definitive operational scenario. Rather, NOAA anticipates operating OCX in an asynchronous manner that uses information from other instruments and models to identify potential regions for scanning/stepping by OCX. To perform its tasks, commanding of OCX for these targeted observations will be based on priorities and availability.

The OCX shall acquire concurrently within 3 hours:

a) Coverage Regions: Either EEZ East Region (EEZE) plus Great Lakes (GL), or EEZ West Region (EEZW). Note that EEZE+GL is larger than EEZW.

b) Any other observations required to meet radiometric and INR requirements

Page 10 of 48 Printed Wednesday, August 23, 2023

ID

OCXPORD104

OCXPORD105

OCXPORD106

OCXPORD107

OCXPORD108

OCXPORD109

OCXPORD110

OCXPORD111

OCXPORD112

Object Number

3.2.1.1.0-2

3.2.1.1.0-3

3.2.1.1.0-4

3.2.1.2

3.2.1.2.0-1

3.2.1.2.0-2

3.2.1.2.0-3

3.2.1.2.0-4

3.2.1.2.0-5

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

Rationale: When covering the driving EEZE plus Great Lakes, the coverage including all calibrations will take 3 hours or less to ensure a timely coverage rate for the instrument that may be used to cover smaller areas in proportionally smaller times.

Nominal coverage from OCX on the GeoXO Imager satellite (GeoI) at 75 W (GeoI- East) will cover EEZE plus Great Lakes and OCX on GeoI-West at 137 W will cover

EEZW.

The OCX shall interrupt current operations by issued command and start the acquisition of a new frame, after a frame coordinate upload, within 30 seconds.

Rationale: The OCX must be commandable to cover regions of interest. Regions will be covered with the same instrument coverage rate, with smaller areas taking proportionally less time.

All corresponding EEZE+GL frames in consecutive revisits shall be spaced at an average time of no more than 3 hours with peak deviation of no more than +/- 30 seconds.

Rationale: The OCX revisit of the entire region should be repeatable if commanded with a regular cadence with limited temporal deviation to support operations.

3.2.1.2 Flexible and Efficient Imaging Pattern

The OCX sensor shall observe an area of commanded size anywhere within the field of regard when commanded.

Rationale: Permits flexible tasking of OCX to regions of interest.

The scan area and geographic location shall be selectable from one frame to the next.

Rationale: Permits flexible tasking of OCX to regions of interest.

The OCX shall be designed such that the Earth-scanning patterns are fully programmable on-orbit.

Rationale: Permits flexible tasking of OCX to regions of interest.

The OCX shall accept fixed grid coordinates for all imaging patterns.

Rationale: Permits mapping to fixed grid.

The OCX shall set the center location of each frame to Fixed Grid Frame coordinates specified by command.

Rationale: Permits centering on fixed grid point for ease of Fixed Grid mapping.

Page 11 of 48 Printed Wednesday, August 23, 2023

ID

OCXPORD211

OCXPORD113

OCXPORD114

OCXPORD115

OCXPORD116

OCXPORD117

OCXPORD118

OCXPORD119

OCXPORD120

OCXPORD123

OCXPORD124

Object Number

3.2.1.2.0-6

3.2.1.3

3.2.1.3.0-1

3.2.1.4

3.2.1.4.0-1

3.2.1.4.0-2

3.2.1.5

3.2.1.5.0-1

3.2.1.5.0-2

3.2.2

3.2.2.1

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

The OCX shall implement an adjustable and commandable scan optimization that accepts priorities from operations and avoids clouds in illuminated regions using an uploaded cloud mask for the cases of a) faster coverage, b) targeted regions of interest.

Rationale: Cloud cover can be variable and requires flexibility in commanding for amount and extent. Adjustable and commandable scan optimization including prioritization by operations will enable either faster acquisition of the coverage regions specified in OCXPORD104 or additional targeted regions of interest.

3.2.1.3 Field of Regard

The OCX Field of Regard (FOR) shall be a minimum of 16.3 degrees to permit observations within the earth's Full Disk.

Rationale: This covers extreme angles of the EEZ.

3.2.1.4 Simultaneity

Corresponding pixels in all spectral channels shall be calculated from detector samples that are collected within 20 seconds of each other.

Rationale: Spectrally simultaneous observations provide observations of the same features and avoid artifacts in resulting data.

All adjacent pixels shall be calculated from detector samples collected within 2 minutes of each other, or OCX shall provide overlap of 42 microradians near adjacent observation edges.

Rationale: This minimum overlap of adjacent observing edges, 42 microradians or 1.5 km at nadir, will provide some shear mitigation for higher-level product processing when the observation edges are not made within 2 min of each other.

3.2.1.5 Data Latency

The OCX shall contribute to the total data latency for the Level 1b product of no more than 5 minutes for calibrated, navigated radiances.

Data latency is measured from the time the instrument collects all samples for an earth scene (or frame) to the time the data is available for dissemination on the ground as Level 1b data. The OCX contribution to data latency includes delay of delivery of data to the spacecraft and delay due to ground algorithm processing (i.e., INR).

Rationale: Latency between the last observation of the input data to the Level 1b processing and the availability of the data for further processing should be as short as practical.

3.2.2 Channel Definitions, SNR, Dynamic Range

3.2.2.1 Baseline

Page 13 of 48 Printed Wednesday, August 23, 2023

ID

OCXPORD130

OCXPORD131

OCXPORD567

OCXPORD132

OCXPORD133

OCXPORD215

OCXPORD216

OCXPORD136

OCXPORD137

OCXPORD138

OCXPORD139

Object Number

3.2.2.2.1.0-1

3.2.2.2.1.0-2

3.2.2.2.1.0-3

3.2.2.2.2

3.2.2.2.2.0-1

3.2.2.2.3

3.2.2.2.3.0-1

3.2.3

3.2.3.1

3.2.3.1.0-1

3.2.3.1.0-2

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

OCX shall collect hyperspectral data with spectral resolution of less than or equal to

0.010 um from 0.670 to 0.680 um.

Rationale: Finer spectral resolution of 0.010 um in this region is driven by chlorophyll-a detection, with at least Nyquist sampling for the 0.010 um preferred. Chlorophyll line is centered at 0.677 um and spans from about 0.665 to 0.690 um.

OCX shall collect hyperspectral data with spectral resolution of less than or equal to

0.020 um over the range specified in OCXPORD125, except for those wavelengths described in OCXPORD130.

Rationale: Spectral resolution of 0.020 um in these regions is driven by other features, with at least Nyquist sampling for the 0.020 um preferred.

OCX shall collect hyperspectral data with at least 2 spectral samples per required spectral resolution element for wavelengths less than or equal to 0.890 um.

3.2.2.2.2 Within Channel Spectral Response Uniformity

The variation in radiance measured between the 1% as-built response points in each spectral channel due to residual spectral differences over the focal plane shall be less than 3x the derived noise for all channels less than or equal to 0.890 um, and reported otherwise including out to 1.02 um, when viewing the simulated upwelling radiance data provided in Ocean Color (OCX) Radiances Upwelling Document, document number 418-XO-RPT-0077.

Rationale: Characterization of spectral features will be employed for processing beyond Level 1b algorithm.

3.2.2.2.3 Channel Center Wavelength Knowledge

The reported spectral sample center wavelength within a channel for any pixel shall have the same spectral sample center wavelength as that reported for any other pixel in the same spectral channel to 0.1 nm, 1-sigma.

Rationale: Constant spectral-sample center information across the FOV is needed for reliable higher product usage. If spectral resampling is needed here, the resampling is not part of the Level 1b algorithm but would be captured in the visualization algorithm.

3.2.3 Spatial Resolution and Sampling

3.2.3.1 System Modulation Transfer Function

The spatial resolution is defined by the sensor system sinusoidal MTF. The following MTF values (exact specification is in cycles/rad) are consistent with 0.3 kilometer resolution in all channels. The spatial frequencies, when referenced to kilometers, are measured at nadir.

The OCX MTF shall meet the requirements in the MTF Requirements Table up to

0.890 um, over the coverage area, in both East/West and North/South directions, after any ground processing, in the presence of jitter, and after any lossy compression/decompression.

Page 15 of 48 Printed Wednesday, August 23, 2023

ID

OCXPORD149

OCXPORD150

OCXPORD151

OCXPORD153

OCXPORD154

OCXPORD155

OCXPORD156

OCXPORD157

OCXPORD159

OCXPORD160

OCXPORD161

OCXPORD162

OCXPORD165

OCXPORD166

Object Number

3.2.4.2.0-1

3.2.4.2.0-2

3.2.4.2.1

3.2.4.2.1.0-1

3.2.4.2.2

3.2.4.2.2.0-1

3.2.4.2.3

3.2.4.2.3.0-1

3.2.4.2.4

3.2.4.2.4.0-1

3.2.4.2.4.0-2

3.2.5

3.2.5.1

3.2.5.1.1

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

All INR requirements listed herein refer to location error of detector samples as expressed in fixed-grid angles; i.e., the requirements apply to the end-to-end system, taking all instrument, spacecraft, and ground processing effects into account. Unless otherwise specified, all INR requirements in this document are specified as North/South and East/West fixed-grid angles, in microradians, 3-sigma, and refer to all hours of operation as defined by the operational zones.

In the context of OCX INR, 3-sigma error is defined to be equal to the 99.73rd percentile of the absolute values of all INR error observations collected over each 24-hour period from local noon to local noon. When INR requirements are temporarily suspended, due to Sun/Earth geometry or maneuver outages (including recovery time), the raw errors during the requirements suspension period should be ignored.

3.2.4.2.1 Navigation

The OCX navigation error shall not exceed 6.3 microradians, 3-sigma, per axis.

3.2.4.2.2 Frame-to-Frame Registration

Frame-to-frame registration error shall not exceed 6.3 microradians, 3-sigma, per axis. Frame-to-frame registration error is the difference in navigation error for an earth location in two consecutive frames within the same channel.

3.2.4.2.3 Within Frame Registration

Within a frame in the same channel, any two pixels shall be separated by the known fixed distance to within an error of 6.3 microradians, 3-sigma, measured radially.

3.2.4.2.4 Channel-to-Channel Registration

Channel-to-channel registration error, or co-registration error, is the difference in line-of-sight fixed-grid angles between spectral channels for any given pixel in the same frame.

Rationale: Co-registration for Level 1b applies to true line-of-sight fixed grid angles rather than the knowledge of those angles.

Co-registration errors between any two spectral channels shall not exceed 1.7 microradians, on a 3-sigma, per axis basis.

Rationale: This uses the same Government methodology as the PRAD.

3.2.5 Radiometric Accuracy and Precision

3.2.5.1 Repeatability

3.2.5.1.1 Pixel-to-Pixel

Page 16 of 48 Printed Wednesday, August 23, 2023

ID

OCXPORD167

OCXPORD172

OCXPORD173

OCXPORD174

OCXPORD175

Object Number

3.2.5.1.1.0-1

3.2.5.2

3.2.5.2.0-1

3.2.5.3

3.2.5.3.0-1

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

For all channels, while viewing a stable, uniform calibration source over expected geostationary environmental conditions and calibration frequency, the OCX shall have a pixel-to-pixel repeatability less than the derived NEDN. Channels will be characterized as if viewing a 100% albedo calibration source.

Rationale: Pixel-to-pixel repeatability should be less than the required noise level to not interefere with scene data collection.

3.2.5.2 Coherent Noise

For all channels, while viewing a stable, uniform calibration source over expected geostationary environmental conditions and calibration frequency, the OCX shall have no spatial coherent noise spectral component exceedances. The spatial coherent noise is defined as the variation in the 2-D Fourier transform of the pixel output of a square region of 0.042 radian by 0.042 radian following all calibration, sampling and detrending. An exceedance is defined as any spatial frequency whose scaled Fourier coefficients are greater than 25 percent of the derived NEDN. The scaled Fourier coefficients are defined using the following equations to scale the amplitude to match the amplitude of a single harmonic.

where x(j,l) are the radiances, N and M are the image size in pixels and Xa are the scaled Fourier coefficients. Detrending allows the removal of scene trends by subtracting the filtered scene using a square box car filter that is 10% of the minimum scene dimension. Edge effects of detrending may be reduced by using a symmetric boundary condition.

Note: The width of bin is defined by the fixed grid spacing. Channels will be characterized as if viewing a 100% albedo calibration source.

Rationale: Coherent noise in a Level 1b product should be less than the one fourth of the noise level to avoid interference.

3.2.5.3 Calibration of Channels

The OCX shall have an on-board optical path calibration capability.

Rationale: An on-board calibration capability of high quality improves near real time calibration accuracy compared to that of vicarious calibration. Additionally, vicarious calibration will also be used.

Page 17 of 48 Printed Wednesday, August 23, 2023

ID

OCXPORD176

OCXPORD177

OCXPORD178

OCXPORD179

OCXPORD180

OCXPORD181

OCXPORD182

OCXPORD183

Object Number

3.2.5.3.0-2

3.2.5.3.0-3

3.2.5.3.0-4

3.2.5.4

3.2.5.4.0-1

3.2.5.4.0-2

3.2.5.5

3.2.5.5.1

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

The OCX shall have an on-board calibration capability for all channels that provides absolute accuracy with traceability to NIST of 2.0%, 1-sigma, or less in the earth albedo measurements for scenes from 3% albedo through 100% albedo.

Rationale: Traceability to NIST (as documented in the SOW) provides improved absolute accuracy for near real time calibration. Calibration of water leaving radiance necessitates calibration accuracy that remains linear down to low albedo levels. Tight absolute accuracy improves the quality of ocean color science as the ocean color signal is a small fraction of the total top of atmosphere scene.

The OCX shall have a calibration capability for all channels that provides drift in calibrated radiances of no more than 0.5% over the OCX lifetime.

Rationale: Instrument degradation over the lifetime, if not corrected in processing, may be misunderstood and changing geophysical parameters over time. Degradation of the instrument and correction method(s) need to be understood and reported to the Government for use in near real time through the instrument Contractor calibration algorithms (updating calibration coefficients)

The OCX shall have a calibration capability for all channels that provides RMS repeatability of 0.2% or less. This requirement is met when no fewer than N independent calibrations are performed as closely as possible together in time and the RMS variation in each calibration coefficient is less than the specified level. N is the number of calibrations required to state at the 90% confidence level that the requirement has been met.

Rationale: Short term RMS repeatability of this level ensures high quality relative accuracy calibration.

3.2.5.4 Spatial Uniformity of Data

The OCX shall have less than 0.3%, 1-sigma, change in response in the calibrated pixel data over the field of regard specified in OCXPORD114 while viewing a stable, uniform calibration source over expected geostationary environmental conditions and calibration frequency.

Rationale: This covers extreme angles of the EEZ.

Channels will be characterized as if viewing a 100% albedo calibration source.

Rationale: Calibrated data needs to be spatial uniform so that variations in the data are not misinterpreted to be real signal variations.

3.2.5.5 Crosstalk

3.2.5.5.1 Channel-to-Channel

Page 18 of 48 Printed Wednesday, August 23, 2023

ID

OCXPORD184

OCXPORD185

OCXPORD186

OCXPORD187

OCXPORD188

OCXPORD189

OCXPORD190

OCXPORD192

OCXPORD193

OCXPORD194

OCXPORD195

Object Number

3.2.5.5.1.0-1

3.2.5.5.2

3.2.5.5.2.0-1

3.2.5.6

3.2.5.6.0-1

3.2.5.7

3.2.5.7.0-1

3.2.5.8

3.2.5.8.1

3.2.5.8.1.0-1

3.2.6

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

The OCX channel-to-channel (electrical, optical, spatial, spectral) crosstalk shall be less than the derived NEDN. Channel-to-channel crosstalk is defined as the change in any channel output when one channel's illumination is changed from 0.1 Nmax to a radiance of Nmax while all other channels remain illuminated at a radiance level less than 0.1 Nmax.

Rationale: Crosstalk between any spectral channels needs to be less than the noise level to minimize spectral artifacts in the data that may be misunderstood to be real features in the data.

3.2.5.5.2 Within Channel

Non-adjacent pixel to pixel within channel cross talk, not including diffraction, shall be less than the derived NEDN. Within channel crosstalk is defined as the change in any non-adjacent pixel when one pixel’s radiance is changed from 0.1 Nmax to a radiance of Nmax while all other pixels in the same band remain illuminated at a radiance level less than 0.1 Nmax.

Rationale: Crosstalk within a spectral channel needs to be less than the noise level to minimize artifacts in the data that may be misunderstood to be real features in the data.

3.2.5.6 Blooming

In all directions from the edge of a 500 by 500 microradian bright target at twice Nmax, all detector outputs in all channels shall recover to normal operation within 24 microradians.

Rationale: Specular solar glint regions are limited to within this spatial distance from the solar sub-point.

3.2.5.7 Quantization Step Size

The quantizing step size for all detector samples shall be less than half the derived

NEDN.

Rationale: Signal quantization by the analog to digital converter should not be the driver in the noise budget in order to avoid having discrete jumps in signal level that can lead to digital artifacts (blocky) data.

3.2.5.8 Polarization

3.2.5.8.1 Polarization Control

Channels shall have less than 3% polarization sensitivity to the incoming light over the FOR specified in OCXPORD114.

Rationale: Polarization sensitivity should be small to limit signal variations with angle.

A polarization sensitivity of less than 3% is important for aerosol characterization for atmospheric correction, particularly 600 nm to 890 nm. Note polarization may vary with wavelength.

3.2.6 System Linearity

Page 19 of 48 Printed Wednesday, August 23, 2023

ID

OCXPORD196

OCXPORD197

OCXPORD198

OCXPORD199

OCXPORD200

OCXPORD201

OCXPORD202

OCXPORD203

OCXPORD204

OCXPORD205

OCXPORD206

OCXPORD207

OCXPORD208

OCXPORD209

OCXPORD210

Object Number

3.2.6.0-1

3.2.7

3.2.7.0-1

3.2.7.0-2

3.2.7.1

3.2.7.1.0-1

3.2.7.2

3.2.7.2.0-1

3.2.7.2.0-2

3.3

3.3.0-1

3.3.0-2

3.3.0-3

3.3.0-4

3.3.0-5

418-XO-OCXPORD-0119, RM Version, Geostationary Extended Observations (GeoXO) Ocean Color (OCX) Performance and

Operational Requirements Document (PORD)

The OCX shall have linear radiometric response, before calibration, such that all points within the dynamic range vary from a linear best fit by no more than 1% of Nmax.

Rationale: Detectors may not be perfectly linear, but small deviations can be well corrected.

3.2.7 Data Compression

The OCX may perform data compression on all data.

Rationale: Data rates may be excessive for downlink without compression.

The OCX may perform lossy data compression.

Rationale: Constraint on application is not to degrade data beyond performance levels

3.2.7.1 Lossless Data Compression

If performed, lossless data compression shall be in accordance with Applicable Document 1 and Applicable Document 2.

Rationale: Lossless data compression when used will follow these references.

3.2.7.2 Lossy Compression

If performed, lossy compression shall not prevent the OCX from meeting requirements, most notably MTF, SNR, and coherent noise.

Rationale: Reference documents provide additional information on data compression.

All calibration data shall be lossless compressed or uncompressed.

3.3 Visualization Algorithm

The OCX Visualization Algorithm (VA) shall provide for visualization of radiances at each spectral channel.

The VA may…