Attachment B PORD.pdf

Effective Date: November 02, 2020 418-XO-GXIPORD-0024 Expiration Date: Five years from date of last signature Version 1.0 Responsible Organization: GEO-XO Flight Project/Code 418

Geostationary and eXtended Orbits Imager (GXI)

Performance & Operational Requirements Document

(PORD)

Signature page

Prepared by:

Electronically approved 11/02/2020

Jemma Klein Date GEO XO Flight Project, System Eng.

NASA GSFC, Code 418

Reviewed by:

Electronically approved 10/28/2020

Alexander Krimchansky Date GEO XO Flight Project, Sys. Eng. Mgr.

NASA GSFC, Code 599

Electronically approved 11/02/2020

Phillip Driggers Date GEO XO Flight Project, Sys. Eng. Mgr.

NASA GSFC, Code 599

Approved by:

Electronically approved 11/02/2020

Jason H. Hair Date GEO XO Flight Project, Project Manager NASA GSFC, Code 418

/GEO-XO Imager

GXIPORD

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document

Version: 1.0 Printed by: rkhoover Printed on: Monday, November 2, 2020

No filter applied.

No sort applied.

Generated from DOORS 9.6.1.11

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 5Applicable Documents

3 6Sensor Requirements

3.1 6Sensor Definition

3.1.1 6Imager Modes

3.1.1.1 6Safe Mode

3.1.1.2 6Normal Operational Mode

3.1.1.3 6Instrument Diagnostic Mode

3.1.1.4 7Outgas Mode

3.1.2 7On-Orbit Operations

3.1.2.1 7Zones of Reduced Data Quality

3.1.2.1.1 7Operational Zone

3.1.2.1.2 7Restricted Zone

3.1.2.2 8Imaging the Sun

3.1.2.3 8Eclipse

3.1.2.4 8Operations After Maneuvers

3.1.2.4.1 8Yaw Flip

3.1.2.4.2 8Stationkeeping

3.1.2.4.3 8Post Storage Activation

3.1.2.5 8Detector Operating Temperatures

3.2 9Sensor Characteristics

3.2.1 9Coverage

3.2.1.1 9Imaging Modes

3.2.1.1.1 9Imaging Mode A

3.2.1.1.2 9Imaging Mode B

3.2.1.1.3 9Full Disk

3.2.1.1.4 9Superregional

Project: GEO-XO Imager Module: GXIPORD Baseline Version: 1.0

Contents ii

3.2.1.1.5 9Mesoscale

3.2.1.2 10Flexible and Efficient Imaging Pattern

3.2.1.3 10Field of Regard

3.2.1.4 10Simultaneity

3.2.1.5 10Data Timeliness

3.2.1.6 11Data Collection Overlap

3.2.2 11Channel Definitions, NEDT, 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 14Within Channel Spectral Response Uniformity

3.2.2.2.3 14Out-of-Band Response

3.2.2.3 14Low Light Visible Channel

3.2.3 14Spatial Resolution and Sampling

3.2.3.1 14System Modulation Transfer Function

3.2.3.2 15Spatial Response Uniformity

3.2.3.3 16Ringing from a Sharp Edge

3.2.4 16Image Navigation and Registration

3.2.4.1 16Star Sensing

3.2.4.2 16INR Performance Requirements

3.2.4.2.1 17Navigation

3.2.4.2.2 17Frame-to-Frame Registration

3.2.4.2.3 17Within Frame Registration

3.2.4.2.4 17Collection-to-Collection Registration

3.2.4.2.5 17Channel-to-Channel Registration

3.2.5 17Radiometric Accuracy and Precision

3.2.5.1 18Calibration and Accuracy for Wavelengths Greater than 3 Microns

3.2.5.1.1 18Full Aperture Calibration

3.2.5.1.2 18Absolute Accuracy

3.2.5.2 18Repeatability

3.2.5.2.1 18Pixel-to-Pixel

3.2.5.2.2 18Collection-to-Collection

3.2.5.2.3 19Channel-to-Channel

3.2.5.2.4 19Image-to-Image

3.2.5.2.5 20Blackbody Calibration-to-Calibration

3.2.5.3 20Coherent Noise

3.2.5.4 21Calibration of Channels Less Than 3 Microns

3.2.5.4.1 21On-Board Calibration

Contents iii

3.2.5.5 22Spatial Uniformity of Data

3.2.5.6 22Crosstalk

3.2.5.6.1 22Channel-to-Channel

3.2.5.6.2 22Within Channel

3.2.5.7 22Blooming

3.2.5.8 22Quantization Step Size

3.2.5.9 22Electronic In-Flight Calibration

3.2.5.10 23Polarization of Channel Less Than 3 Microns

3.2.5.10.1 23Polarization Control

3.2.6 23System Linearity

3.2.7 23Data Compression

3.2.7.1 23Lossless Data Compression

3.2.7.2 23Lossy Compression

3.3 23Design Requirements

3.3.1 24Reliability

3.3.2 24Mechanical Requirements

3.3.2.1 24Design Limit Loads

3.3.2.2 24Nonlinear Loads

3.3.2.3 24Yield Strength

3.3.2.4 24Ultimate Strength

3.3.2.5 25Structural Stiffness

3.3.2.6 25Unit Stiffness

3.3.2.7 25Material Properties

3.3.2.8 25Critical Members Design Values

3.3.2.9 25Redundant Members Design Values

3.3.2.10 26Selective Design Values

3.3.2.11 26Structural Reliability

3.3.2.12 26Mechanisms

3.3.2.13 27Pressurized Units

3.3.2.14 27Alignment Reference

3.3.3 27Thermal Requirements

3.3.3.1 27Temperature Limits

3.3.3.2 27Non Operational Temperature

3.3.3.3 27Thermal Control Hardware

3.3.3.4 27Detector Cooling Margin

3.3.4 28Onboard Processors Requirements

3.3.4.1 28Flight Load Non-Volatile Memory

3.3.4.2 28Commandable Reinitialization

Contents iv

3.3.4.3 28Deterministic Power-on Configuration

3.3.4.4 28Fail-safe Recovery Mode

3.3.5 28Flight Software Requirements

3.3.5.1 28Language and Methodology

3.3.5.2 28Flight Software Upload

3.3.5.3 29Flexibility and Ease of Software Modification

3.3.5.4 29Version Identifiers

3.3.5.5 29Flight Processor Resource Sizing

3.3.5.6 29Software Event Logging

3.3.5.7 30Warm Restart

3.3.5.8 30Memory Tests

3.3.5.9 30Memory Dump

3.3.5.10 30Telemetry

3.3.6 30Power Requirements

3.3.6.1 30Power Regulators and Supplies

3.3.6.2 30Fuses

3.3.6.3 30Test Connectors

3.3.7 30Magnetic Properties

3.3.8 31Spacecraft Level Ground Testing

3.3.9 31Ground Support Equipment and Development Facilities

3.3.9.1 31Electrical System Test Equipment

3.3.9.2 31Flight Software Development Environment

3.3.9.3 32Shipping Container

3.3.9.4 32Instrument Emulator

4 34Acronyms

5 35Design Verification Requirements

5.1 35Performance Operating Time and Trouble-Free Performance Testing

5.2 35Structural and Mechanical Verification Requirements

5.2.1 35Mechanical Test Factors and Duration

5.2.2 35Minimum Workmanship

5.2.3 35Testing in Flight Configuration

5.2.4 35Structural Proof Testing

5.2.5 35Modal Survey Characterization

5.2.6 36Structural Qualification

5.2.7 36Deployment and Articulation Verification

5.2.8 36Life Test

5.2.9 37Mechanical Clearance Verification

Contents v

5.3 37Electromagnetic Compatibility Requirements

5.3.1 37General

5.3.2 37Electrostatic Arc-Discharge Susceptibility

5.3.2.1 37External Surface-to-Surface direct discharge

5.3.2.2 37Deep Dielectric Charging

5.3.2.3 37ESD Characteristics

5.4 38Magnetic Properties

5.4.1 38General

5.5 38Thermal Requirements

5.5.1 38General

5.5.1.1 38Test Chronology

5.5.1.2 39Thermal Test Chronology

5.5.1.3 39Pressure

5.5.2 39Thermal Vacuum

5.5.2.1 39Transition Rates

5.5.2.2 39Corona Operation

5.5.2.3 39Hot and Cold Start Demonstrations

5.5.2.4 39Heater Verification

5.5.2.5 40Flight Temperature Sensor Verification

5.5.3 40Thermal Cycling

5.5.3.1 40Spacecraft Level TV Test

5.5.3.2 40Cumulative Cycles

5.5.3.3 40Instrument Level TV Cycling

5.5.3.4 40Unit Level TV Cycling

5.5.3.5 41Ambient Pressure Thermal Cycling Substitution

5.5.3.6 41Test Temperatures

5.5.3.6.1 41Mission Allowable Temperatures

5.5.3.6.2 41Qualification, Protoflight and Acceptance Temperatures

5.5.3.6.3 42Non-operating Temperatures

5.5.3.7 42Temperature test tolerances

5.5.3.8 42Plateau Criteria

5.5.4 42Thermal Balance (TB)

5.5.4.1 42TB Applicability

5.5.4.2 42Balance Points

5.5.4.3 42TB-Instrument Configuration

5.5.4.4 43TB Accuracy and Knowledge

5.5.4.5 43TB Steady State Criteria

5.6 43Test Condition Tolerances

Contents vi

5.6.1 43General

6 46Appendix 1

6.1 47Priority 1

6.2 48Priority 2

6.3 49Priority 3

Contents vii

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ID

GXIPORD1

GXIPORD2

GXIPORD3

GXIPORD4

GXIPORD5

GXIPORD6

GXIPORD10

GXIPORD11

GXIPORD12

GXIPORD13

GXIPORD14

GXIPORD15

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

1.2.0-5

1.3

1.3.0-1

1.4

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) 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 and eXtended orbits Imager (GXI). The imager may incorporate additional capabilities described in Appendix 1.

1.2 Mission Review

The GXI is a multi-channel, visible through infrared, passive imaging radiometer used to measure environmental data as part of a 3-axis stabilized, geostationary weather satellite system. The GXI remotely collects imagery of the Earth’s surface (land and water) and atmosphere to aid in the prediction of weather and climate monitoring. The data provide adequate spatial, temporal and radiometric resolution to accurately monitor rapidly changing weather.

The imager objectives are as follows:

a) Provide environmental data that will be used by NOAA and other public and private agencies to produce routine meteorological analyses and forecasts.

b) Maintain continuity of Geostationary-eXtended Orbits (GEO-XO) services to the user agencies.

c) Provide environmental data that will be used to expand knowledge of mesoscale and synoptic scale storm development and provide data that may be used to help in forecasting severe weather events.

The imager instrument provides data to the Ground System via the spacecraft communication system. The Ground System takes the data, spacecraft telemetry data, orbit determination data and other required information and autonomously generates radiometrically calibrated and navigated data for the NOAA users.

The Ground System will be procured by the Government but will implement algorithms developed by the GXI contractor to satisfy performance requirements.

The Ground System will calibrate and then resample the data to generate the fixed grid. Resampling requires that the raw imagery be adequately sampled to maintain radiometric accuracy after resampling.

1.3 Document Overview

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

1.4 Terminology

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ID

GXIPORD16

GXIPORD17

GXIPORD696

GXIPORD697

GXIPORD698

GXIPORD699

GXIPORD18

GXIPORD19

GXIPORD20

GXIPORD21

GXIPORD22

GXIPORD23

GXIPORD24

GXIPORD25

GXIPORD26

Object Number

1.4.0-1

1.4.0-2

1.4.0-3

1.4.0-4

1.4.0-5

1.4.0-6

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

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

The term “(TBS)”, which means “to be specified”, means that the contractor will supply the missing information in the course of the contract. These serve as a placeholder for future requirements. The contractor is not liable for compliance with these “placeholder” requirements, as insufficient information is provided on which to base a design.

The term “(TBR)”, which means “to be refined/reviewed”, means that the requirement is subject to review for appropriateness and subject to revision. The contractor is liable for compliance with the requirement as if the “TBR” notation did not exist. The “TBR” merely provides an indication that the value is more likely to change in a future modification than requirements not accompanied by a

“TBR”.

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

The use of “should” designates good practice.

The use of “will” is a statement of fact.

The use of “may” designates permission by the Government.

1.5 Definitions

Throughout this document, the following definitions apply (note that Appendix 1 has optional updates to some terms):

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.

All requirements/all performance requirements/all operational requirements:

Refers to any performance characteristic or requirement in the GXIPORD, GXIUIID, and the GIRD.

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.

Fixed Grid Format: Refers to the idealized geoeferenced positions for pixel locations. The fixed grid has the following characteristics:

a) The fixed grid is rectified to a GRS80 geoid viewed from the idealized geostationary position.

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ID

GXIPORD26

GXIPORD38

GXIPORD39

GXIPORD40

GXIPORD41

GXIPORD42

GXIPORD43

GXIPORD44

GXIPORD45

Object Number

1.5.0-8

1.5.0-9

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

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

b) The pixels have the same angular separation for East/West and North/South.

c) From the viewpoint of a right-hand coordinate system of the idealized geostationary satellite with its x-axis in the direction of the velocity and the z-axis pointed at nadir, the North/South angle is determined by a rotation about the x-axis and the East/West angle is determined by a rotation about the rotated y-axis.

d) For the 0.64 micron channel the angular separation is 14 microradians.

e) For the 0.47, 0.55, 0.865, 1.61, and 3.9 micron channels the angular separation is 28 microradians.

f) For all other channels, the angular separation is 56 microradians.

g) The center of the 14 microradian grid is offset by 7 microradians in both directions from the center of the 28 microradian grid such that four 14 microradian pixels fill the same area as a single 28 microradian pixel.

h) The center of the 28 microradian grid is offset by 14 microradians in both directions from the center of the 56 microradian grid such that four 28 microradian pixels fill the same area as a single 56 microradian pixel.

i) The ideal sub-satellite point is at the corner of a pixel on the 14, 28, and 56 microradian grids.

j) Pixels are defined out to the edge of the earth's limb as defined by the GRS80 ellipsoid from the ideal geosynchronous satellite.

k) For the purposes of commanding targets off the limb of the earth the reference frame is the fixed grid defined in item c).

Full Disk: Defined as a 17.4 degree diameter circle centered at nadir, plus any additional imaging required for uncompensated non ideal orbit and image motion compensation.

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.

Image: Refers to a full disk, superregional, or mesoscale image in the fixed grid.

Image Navigation: Refers to the determination of the location of each image pixel relative to a fixed reference, such as fixed-grid angle coordinates.

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

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

Mesoscale Region: Defined as the equivalent of a 1.6043 x 1.6043 degree, 1000 (TBS) x 1000 (TBS) kilometer nadir-viewed area.

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

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ID

GXIPORD46

GXIPORD47

GXIPORD48

GXIPORD49

GXIPORD50

GXIPORD51

GXIPORD52

GXIPORD53

GXIPORD54

Object Number

1.5.0-17

1.5.0-18

1.5.0-19

1.5.0-20

1.5.0-21

1.5.0-22

1.6

1.6.0-1

1.6.0-2

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

Pixel: Applies to data samples after resampling during the ground processing.

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.

Superregional: Defined as the equivalent of a 5000 kilometer East/West x 3000 kilometer North/South nadir-viewed area.

Transfer Orbit: The sequence of events that transpires to establish the GEO-XO satellite on-station after the GEO-XO 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 GXIPORD pertain to the GXI ‘system’, which may include motors, optics, detectors, signal processing electronics and software, and ground processing. The GXI 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 imager. Data performance requirements, such as Modulation Transfer Function (MTF) and Image Navigation and Registration (INR), apply to data after all ground processing, except as indicated.

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ID

GXIPORD55

GXIPORD56

Object Number

2.0-1

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

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

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

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

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

Space Mechanisms Handbook, Document Number NASA TP-1999-206988

General Environmental Verification Specification For GSFC Flight Programs and Projects, Document Number GSFC-STD-7000A, April 22, 2013

AFSPCMAN 91-710, Air Force Space Command Manual 91-710 (AFSPCMAN 91-710), Range Safety Requirements, July 2004

Standard General Requirements for Safe Design and Operation of Pressurized Missile and Space Systems, Document Number MIL-STD-1522A, Sept. 4, 1992

Radiance Upwelling, 417-R-RPT-0064, dated May 3, 2004

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ID

GXIPORD65

GXIPORD66

GXIPORD67

GXIPORD68

GXIPORD69

GXIPORD70

GXIPORD71

GXIPORD72

GXIPORD73

GXIPORD74

GXIPORD75

GXIPORD76

GXIPORD77

GXIPORD78

GXIPORD79

GXIPORD80

GXIPORD81

GXIPORD82

GXIPORD83

GXIPORD84

GXIPORD85

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

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

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

3 Sensor Requirements

3.1 Sensor Definition

3.1.1 Imager Modes

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

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

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

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

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

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

3.1.1.1 Safe Mode

The imager shall implement a Safe Mode.

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

The imager shall enter Safe Mode upon detection of internal faults capable of causing permanent damage to the instrument.

3.1.1.2 Normal Operational Mode

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

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

3.1.1.3 Instrument Diagnostic Mode

The imager shall implement an Instrument Diagnostic Mode.

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

The imager shall by command send selected channels while in Instrument Diagnostic Mode.

The imager shall by command send the individual measurement in those cases where TDI data is digitally processed off the focal plane while in Instrument Diagnostic Mode.

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ID

GXIPORD86

GXIPORD87

GXIPORD88

GXIPORD89

GXIPORD90

GXIPORD91

GXIPORD92

GXIPORD93

GXIPORD94

GXIPORD95

GXIPORD96

GXIPORD97

GXIPORD98

GXIPORD100

Object Number

3.1.1.3.0-5

3.1.1.3.0-6

3.1.1.3.0-7

3.1.1.3.0-8

3.1.1.3.0-9

3.1.1.4

3.1.1.4.0-1

3.1.1.4.0-2

3.1.2

3.1.2.1

3.1.2.1.1

3.1.2.1.1.0-1

3.1.2.1.1.0-2

3.1.2.1.2

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

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

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

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

The imager shall by command perform electronic in-flight calibration while in Instrument Diagnostic Mode.

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

3.1.1.4 Outgas Mode

The imager shall implement an Outgas Mode.

The imager shall sublimate and evaporate contaminants from hardware to prevent contamination from jeopardizing performance while in Outgas Mode.

3.1.2 On-Orbit Operations

3.1.2.1 Zones of Reduced Data Quality

3.1.2.1.1 Operational Zone

The imager shall meet all of its performance requirements for all pixels in channels greater than 3 microns whose distance from the center of the uneclipsed portion of the sun is greater than 7.5 degrees.

The imager shall meet all of its performance requirements for all pixels in channels less than 3 microns when the distance from the center of the sun to any part of the earth is greater than the limits in the Operational Zones Table.

Operational Zones Table

Channel Outer Limit Low light 10° All other reflective 30°

3.1.2.1.2 Restricted Zone

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ID

GXIPORD101

GXIPORD103

GXIPORD104

GXIPORD105

GXIPORD106

GXIPORD107

GXIPORD108

GXIPORD109

GXIPORD110

GXIPORD111

GXIPORD112

GXIPORD113

GXIPORD114

GXIPORD115

GXIPORD116

GXIPORD117

GXIPORD118

Object Number

3.1.2.1.2.0-1

3.1.2.2

3.1.2.2.0-1

3.1.2.3

3.1.2.3.0-1

3.1.2.3.0-2

3.1.2.4

3.1.2.4.1

3.1.2.4.1.0-1

3.1.2.4.2

3.1.2.4.2.0-1

3.1.2.4.3

3.1.2.4.3.0-1

3.1.2.5

3.1.2.5.0-1

3.1.2.5.0-2

3.1.2.5.0-3

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

For all pixels in channels greater than 3 microns whose distance from the center of the uneclipsed portion of the sun is between the inner and outer limits shown in the Restricted Zones Table, the imager shall meet all requirements, except for a factor of two degradation of the SNR and NEDT requirements stated in requirement number GXIPORD161, a factor of two degradation of the absolute accuracy requirement stated in GXIPORD309, and a navigation relaxation as described in GXIPORD292.

Restricted Zones Table

Channel Inner Limit Outer Limit <4.5 micrometers 5° 7.5° All others 3° 7.5°

3.1.2.2 Imaging the Sun

The imager shall be able to image the sun for 4 seconds, two times within 30 seconds or less, without interrupting normal imaging operations or sustaining damage.

3.1.2.3 Eclipse

The imager shall be capable of continuous operation through eclipse periods.

During eclipse periods, for all channels with wavelengths greater than 3 microns, the imager shall meet all requirements, except as noted in requirement number

GXIPORD292.

3.1.2.4 Operations After Maneuvers

3.1.2.4.1 Yaw Flip

The imager 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.

3.1.2.4.2 Stationkeeping

The imager shall meet all radiometric, coverage and INR requirements within 2 minutes after the spacecraft interface has returned to being within specification following spacecraft stationkeeping maneuvers.

3.1.2.4.3 Post Storage Activation

The imager shall meet all requirements within 5 days of turn on after post storage activation for passively cooled detectors and 3 days for actively cooled detectors.

3.1.2.5 Detector Operating Temperatures

The detector operation temperatures shall be selectable by command.

The detector control temperature shall be in 1K increments or smaller.

The detector control temperature shall be at least +10K/-5K of the nominal operational temperature.

Page 9 of 50 Printed Monday, November 2, 2020

ID

GXIPORD119

GXIPORD120

GXIPORD121

GXIPORD122

GXIPORD123

GXIPORD124

GXIPORD125

GXIPORD126

GXIPORD131

GXIPORD132

GXIPORD135

GXIPORD136

GXIPORD137

GXIPORD138

GXIPORD139

GXIPORD140

Object Number

3.1.2.5.0-4

3.2

3.2.1

3.2.1.1

3.2.1.1.0-1

3.2.1.1.0-2

3.2.1.1.1

3.2.1.1.1.0-1

3.2.1.1.2

3.2.1.1.2.0-1

3.2.1.1.3

3.2.1.1.3.0-1

3.2.1.1.3.0-2

3.2.1.1.4

3.2.1.1.4.0-1

3.2.1.1.5

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

The precision on the control temperatures of the detectors shall be less than +/-

0.5 K.

3.2 Sensor Characteristics

3.2.1 Coverage

3.2.1.1 Imaging Modes

Routine operations, such as uploading commands and data to the imager, shall not interfere with data collection in any imaging mode.

The imager shall be capable of interrupting current operations by command and starting the acquisition of a new image, after an image coordinate upload, within 30 seconds.

3.2.1.1.1 Imaging Mode A

The imager shall acquire concurrently:

a) Full Disks at 10 minute intervals

b) Superregional images at 5 minute intervals, any of which may be extracted from the full disk images if the timing is correct

c) A Mesoscale image at 30 second intervals

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

3.2.1.1.2 Imaging Mode B

The imager shall acquire concurrently:

a) Full Disks at 5 minute intervals,

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

3.2.1.1.3 Full Disk

In Mode A, an image of the Full Disk shall be acquired with all corresponding pixels in consecutive frames spaced at an average time of 10 minutes with a peak deviation of no more than ± 30 seconds.

In Mode B, an image of the Full Disk shall be acquired with all corresponding pixels in consecutive frames spaced at an average time of 5 minutes with a peak deviation of no more than ± 5 seconds.

3.2.1.1.4 Superregional

In Mode A, an image of the supperregional area shall be acquired with all corresponding pixels in consecutive frames spaced at an average time of 5 minutes with peak deviation of no more than +/- 30 seconds. The design may assume that the spacecraft x axis is parallel to the Earth’s equator within the accuracy as stated in the GIRD.

3.2.1.1.5 Mesoscale

Page 10 of 50 Printed Monday, November 2, 2020

ID

GXIPORD141

GXIPORD142

GXIPORD143

GXIPORD144

GXIPORD145

GXIPORD146

GXIPORD147

GXIPORD148

GXIPORD149

GXIPORD150

GXIPORD151

GXIPORD152

GXIPORD153

GXIPORD154

GXIPORD155

GXIPORD156

Object Number

3.2.1.1.5.0-1

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

3.2.1.2.0-6

3.2.1.2.0-7

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

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

In Mode A, an image of a Mesoscale region viewed anywhere in the Field of Regard shall be acquired with all corresponding pixels in consecutive frames spaced at an average time of no more than 30 seconds apart with a peak deviation of +/- 5 seconds.

3.2.1.2 Flexible and Efficient Imaging Pattern

The imager shall be designed such that the imaging patterns are flexible and programmable on-orbit.

The imager shall accept fixed grid coordinates for all Imaging Modes.

In addition to Full Disk images, the imager shall have the capability to program least two superregional images at any given time.

The imager shall autonomously adjust the Imaging Pattern to avoid imaging within a ground definable angle from the center of the sun.

If star sensing is used, the imager shall autonomously onboard compute the position of stars and adjust the imaging pattern to acquire them (with any adjusted pattern still meeting all other requirements in this document).

The imaging pattern shall be definable by ground modifiable parameters such that full disk, superregional, and mesoscale images, other image regions and sizes, space looks, IR calibration, and star sensing are performed at any user-defined intervals that are consistent with the imaging rates used in predefined imaging modes. These data items will be uploaded during earlier operations and activated with a single command.

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

3.2.1.3 Field of Regard

The unvignetted Field of Regard (FOR) shall include a circle of at least 20 degrees in diameter with its center at the sub-satellite point and accounting for alignment errors as described in the GIRD.

3.2.1.4 Simultaneity

Corresponding pixels in all spectral channels shall be calculated from detector samples that are collected within 5 seconds of each other.

All adjacent pixels shall be calculated from detector samples collected within 30 seconds of each other.

3.2.1.5 Data Timeliness

The imager shall contribute to the total data latency no more than: 50 seconds for a Superregional calibrated, navigated image; 20 seconds for a Mesoscale calibrated navigated image; and 50 seconds for a Full Disk calibrated, navigated image.

Page 11 of 50 Printed Monday, November 2, 2020

ID

GXIPORD157

GXIPORD158

GXIPORD159

GXIPORD160

GXIPORD161

GXIPORD162

GXIPORD163

GXIPORD165

Object Number

3.2.1.5.0-2

3.2.1.6

3.2.1.6.0-1

3.2.2

3.2.2.1

3.2.2.1.0-1

3.2.2.1.0-2

3.2.2.1.0-3

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

Data latency is measured from the time the instrument acquires all samples for a scene to the time the image is available for dissemination on the ground. The imager contribution to data latency includes delay of delivery of data to the spacecraft and delay due to ground algorithm processing (i.e., resampling and

INR).

3.2.1.6 Data Collection Overlap

The imager shall generate each pixel from detector samples contained in a single data set.

3.2.2 Channel Definitions, NEDT, Dynamic Range

3.2.2.1 Baseline

The imager shall collect imagery in the following 17 channels designated by their center wavelength in microns: 0.47, 0.55, 0.64, 0.865, 1.378, 1.61, 2.25, 3.9, 6.185, 6.95, 7.34, 8.5, 9.61, 10.35, 11.2, 12.3, 13.3.

The imager shall meet the SNR, and NEDT listed in the following Radiometric Precision Table.

Radiometric Precision Table

Center Wavelength

Microns

NEDT

@300K +/- 1K

(K)

NEDT

@240K +/- .5K

(K)

SNR at 100% albedo

0.47 - - SNR=300:1

0.55 - - SNR=300:1

0.64 - - SNR=300:1

0.865 - - SNR=300:1

1.378 - - SNR=300:1

1.61 - - SNR=300:1

2.25 - - SNR=300:1

3.9 0.30 1.4

6.185 0.10 0.4

6.95 0.10 0.37

7.34 0.10 0.32

8.5 0.10 0.27

9.61 0.10 0.22

10.35 0.10 0.21

11.2 0.10 0.19

12.3 0.10 0.18

13.3 0.30 0.48

The imager shall meet the dynamic range listed in the following Dynamic Range Table for detector samples.

Page 12 of 50 Printed Monday, November 2, 2020

ID

GXIPORD165

GXIPORD167

GXIPORD168

GXIPORD169

Object Number

3.2.2.1.0-3

3.2.2.2

3.2.2.2.1

3.2.2.2.1.0-1

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

Dynamic Range Table

Center Wavelength Microns

Scene Tmin (K)

Scene Tmax (K)

Nmax

(mW/m2/sr/cm-1)

0.47 N/A - 14.4

0.55 N/A - 17.8

0.64 N/A -

21.1

1.05 (low light)

0.865 N/A - 22.8

1.378 N/A - 21.7

1.61 N/A - 20.0

2.25 N/A - 12.1

3.9 4 400

6.185 4 300

6.95 4 300

7.34 4 320

8.5 4 330

9.61 4 300

10.35 4 330

11.2 4 330

12.3 4 330

13.3 4 305

3.2.2.2 System Spectral Response

3.2.2.2.1 Spectral Response Envelope

The ABI system spectral response shall conform to the envelope per the Spectral Response Figure and Table.

Page 14 of 50 Printed Monday, November 2, 2020

ID

GXIPORD171

GXIPORD172

GXIPORD173

GXIPORD174

GXIPORD175

GXIPORD177

GXIPORD178

GXIPORD179

GXIPORD180

GXIPORD181

GXIPORD182

Object Number

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

3.2.2.2.3.0-2

3.2.2.3

3.2.2.3.0-1

3.2.3

3.2.3.1

3.2.3.1.0-1

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

When viewing the four government-supplied simulated upwelling radiance data sets in 417-R-RPT-0064, the brightness temperature error due to the uncertainty in the spectral response between the 1% as-built response points shall be less than 1K for all channels with center wavelength greater than 3 microns.

3.2.2.2.2 Within Channel Spectral Response Uniformity

When viewing the simulated upwelling radiance data sets in 417-R-RPT-0064 and when viewing the default solar irradiance spectrum from MODTRAN version 4V1R1 (newkur.dat) with the assumption that clouds have Lambertian reflectance with an albedo not less than 50%, the variation in radiance measured between the 1% as-built response points in each spectral channel, due to spectral differences over the focal plane, shall be less than the derived NEDN for all channels.

3.2.2.2.3 Out-of-Band Response

The out-of-band response is defined in the equation as one minus the integrated response between the as-built 1% response points divided by the integrated response from 0.3 microns to 20 microns. Out-of-band response shall be less than 0.25% of the signal for the 1.378 micron channel and 1% of the total signal for all other channels when viewing either a 300 K blackbody (for channel wavelengths greater than 3 microns) or a 100% albedo scene above the atmosphere assuming no attenuation.

Out-of-Band Response Equation responsespectralrelativechanneltheis)( andalbedo100%or blackbody K 300)( where0.01

-11)(Equation

3.0

%1

R

N dRN dRN m responsespectralrelativechanneltheis)( andalbedo100%or blackbody K 300)( where0.01

-11)(Equation

3.0

R dRN dRN

3.2.2.3 Low Light Visible Channel

The imager shall include a low light level (5% albedo) visible (0.64 microns) imaging capability at 20:1 SNR with performance equivalent to the 0.64 microns visible channel except as noted in requirement GXIPORD101 and between the 10 and 30 degrees defined in GXIPORD97 where a factor of two degradation of the MTF requirement (defined as factor of two decrease in specified spatial frequency) stated in GXIPORD182 is imposed.

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 0.5 kilometer resolution in the 0.64 micron channel, 1.0 kilometer resolution in the 0.47, 0.55, 0.865, 1.61, and 3.9 micron channels, and 2.0 kilometer resolution in all other channels. The spatial frequencies, when referenced to kilometers, are

Page 15 of 50 Printed Monday, November 2, 2020

ID

GXIPORD182

GXIPORD185

GXIPORD186

GXIPORD187

GXIPORD188

Object Number

3.2.3.1.0-1

3.2.3.2

3.2.3.2.0-1

3.2.3.2.0-2

3.2.3.2.0-3

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD) measured at nadir. The imager system MTF shall meet the requirements in the following tables over the Full Disk image area, in both East/West and North/South directions, after any ground processing, in the presence of jitter, when averaged over all resampling phases of the detector sample grid to pixel grid, and after any lossy compression/decompression.

MTF Emissive Channel Requirements Table

Emissive channels with 1 km resolution Emissive channels with 2 km resolution

Spatial Period

Spatial Frequency

System

MTF

Spatial Period

Spatial Frequency

System MTF km/cyc cyc/rad km/cyc cyc/rad

8.0 4500 0.84 16.0 2250 0.84

4.0 9000 0.62 8.0 4500 0.62

2.666 13500 0.39 5.333 6750 0.39

2.0 18000 0.22 4.0 9000 0.22

MTF Reflective Channel Requirements Table

0.64 micron channel

0.47, 0.55, 0.86,1.61 micron channels

1.38, 2.25 micron channels

Spatial Period

Spatial Frequency

System

MTF

Spatial Period

Spatial Frequency

System

MTF

Spatial Period

Spatial Frequency

System

MTF

km/cyc cyc/rad km/cyc cyc/rad km/cyc cyc/rad

4.0 9000 0.90 8.0 4500 0.90 16.0 2250 0.90

2.0 18000 0.73 4.0 9000 0.73 8.0 4500 0.73

1.333 27000 0.53 2.666 13500 0.53 5.333 6750 0.53

1.0 36000 0.32 2.0 18000 0.32 4.0 9000 0.32

3.2.3.2 Spatial Response Uniformity

Effects of co-registration and jitter may be ignored for the purposes of evaluating these requirements (GXIPORD186 through 188 and GXIPORD190 through 192).

The normalized radiance difference due to spatial response differences between corresponding pixels in any two spectral channels with a center wavelength greater than 3 microns located X (continuous variable) microradians from the edge of a 1000 by 1000 microradian or larger target with radiance equal or greater than 300 K surrounded by a large region of radiance equal to or less than 240 K shall agree to within 4 % of the step radiance difference for an rms over the sampling-to-edge phasing and the channel-to-channel relative phasing. The calculation of this normalized difference is expressed in equation form below.

Here the overbar represents an average over multiple samples located well away from the edge. This normalized radiance difference due to spatial response differences applies in all four directions, i.e. left of, right of, above, and below the target box. The values of X include all distances between +84 microradians and -84 microradians.

Page 16 of 50 Printed Monday, November 2, 2020

ID

GXIPORD188

GXIPORD190

GXIPORD191

GXIPORD192

GXIPORD193

GXIPORD194

GXIPORD199

GXIPORD200

GXIPORD201

GXIPORD202

GXIPORD203

Object Number

3.2.3.2.0-3

3.2.3.2.0-4

3.2.3.2.0-5

3.2.3.2.0-6

3.2.3.3

3.2.3.3.0-1

3.2.4

3.2.4.1

3.2.4.1.0-1

3.2.4.2

3.2.4.2.0-1

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD) normnorm norm norm

SLDiff

SS

SSS

LL

LLL

240300

240300

Any efforts to blur or enhance channel resolution to match that of other emissive (greater than 3 microns) channels shall be performed in ground system software, not within the instrument.

The reflectance difference due to spatial response differences between corresponding pixels in any two spectral channels with a center wavelength less than 3 microns located X (continuous variable) microradians from an edge of a 1000 by 1000 microradian or larger target with radiance equal to Nmax (see requirement GXIPORD162) surrounded by a large region of radiance equal to or less than 5% Nmax shall be less than 4% of the step function for an rms over the sampling-to-edge phasing and the channel-to-channel relative phasing.

Any efforts to blur or enhance channel resolution to match that of other reflective (less than 3 microns) channels shall be performed in ground system software, not within the instrument.

3.2.3.3 Ringing from a Sharp Edge

For both the North/South and East/West edges, the imager shall not overshoot the top of an edge or undershoot the bottom of edge by more than 2% of the height of the edge where:

a) The height and the overshoot/undershoot are measured in radiance units.

b) The edge delineates a 10% albedo region from a 90% albedo region for channels less than 3 microns.

c) The edge delineates a 240K region from a 300K region for channels greater than 3 microns.

d) The overshoot is averaged over all resampling phases of the detector sample grid to pixel grid and edge position to detector sample grid.

3.2.4 Image Navigation and Registration

3.2.4.1 Star Sensing

If star sensing is employed onboard, the imager shall have an on-board star catalog which is loadable and modifiable from the ground.

3.2.4.2 INR Performance Requirements

All INR requirements listed herein refer to location error of the fixed-grid pixels;

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 angles, in microradians, 3-sigma, and refer to all hours of operation.

Page 17 of 50 Printed Monday, November 2, 2020

ID

GXIPORD204

GXIPORD205

GXIPORD206

GXIPORD207

GXIPORD208

GXIPORD209

GXIPORD210

GXIPORD211

GXIPORD212

GXIPORD213

GXIPORD214

GXIPORD215

GXIPORD216

GXIPORD221

Object Number

3.2.4.2.0-2

3.2.4.2.1

3.2.4.2.1.0-1

3.2.4.2.1.0-2

3.2.4.2.2

3.2.4.2.2.0-1

3.2.4.2.2.0-2

3.2.4.2.3

3.2.4.2.3.0-1

3.2.4.2.4

3.2.4.2.4.0-1

3.2.4.2.5

3.2.4.2.5.0-1

3.2.5

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

In the context of imager 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 instrument navigation error shall not exceed 21 microradians, 3-sigma, per axis, except during eclipse periods.

For up to a four hour period that includes a total or partial eclipse of the sun, the imager navigation requirement in GXIPORD203 shall be relaxed to not exceed +/- 32 microradians. The phasing of the four hour relaxation relative to the eclipse may be design-specific and is TBS.

3.2.4.2.2 Frame-to-Frame Registration

Frame-to-frame registration error shall not exceed 17.6 microradians, 3-sigma, per axis, for channels with a center wavelength less than 4 microns. Frame-to-frame registration error is the difference in navigation error for any given pixel in two consecutive images within the same channel.

Frame-to-frame registration error shall not exceed 23 microradians, 3-sigma, per axis, for channels with a center wavelength greater than 4.5 microns.

3.2.4.2.3 Within Frame Registration

Within an image in the same channel, any two pixels shall be separated by the known fixed distance to within 21 microradians, 3-sigma, measured radially.

3.2.4.2.4 Collection-to-Collection Registration

Collection-to-collection registration error shall not exceed 7.8 microradians, 3-sigma, per axis, where the collection-to-collection error is the relative location error of adjacent pixels across a collection boundary within the same channel.

3.2.4.2.5 Channel-to-Channel Registration

Channel-to-channel registration error, or co-registration, is the difference in navigation errors between spectral channels for any given pixel in the same frame.

The channel-to-channel registration requirements depend on the fixed-grid resolutions of the channels. Co-registration errors between any two spectral channels shall not exceed the values shown in the Channel-to-Channel Registration table, on a 3-sigma, per axis basis.

Channel‐to‐Channel Registration Table

2‐km 1‐km 0.5‐km 2‐km 11.2 microradians 11.2 microradians 11.2 microradians 1‐km ‐‐ 6.0 microradians 6.0 microradians

3.2.5 Radiometric Accuracy and Precision

Page 18 of 50 Printed Monday, November 2, 2020

ID

GXIPORD222

GXIPORD223

GXIPORD224

GXIPORD225

GXIPORD226

GXIPORD227

GXIPORD228

GXIPORD229

GXIPORD230

GXIPORD231

GXIPORD233

GXIPORD234

GXIPORD235

Object Number

3.2.5.1

3.2.5.1.1

3.2.5.1.1.0-1

3.2.5.1.2

3.2.5.1.2.0-1

3.2.5.2

3.2.5.2.1

3.2.5.2.1.0-1

3.2.5.2.1.0-2

3.2.5.2.1.0-3

3.2.5.2.1.0-4

3.2.5.2.2

3.2.5.2.2.0-1

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

3.2.5.1 Calibration and Accuracy for Wavelengths Greater than 3 Microns

3.2.5.1.1 Full Aperture Calibration

The imager shall have full system, end-to-end, and full aperture on-board calibration channels with wavelengths greater than 3 microns.

3.2.5.1.2 Absolute Accuracy

The imager data shall be calibrated to an absolute accuracy with traceability to NIST of +/- 1 K (one sigma) at a 300 K reference temperature (Ref SOW for details on traceability).

3.2.5.2 Repeatability

3.2.5.2.1 Pixel-to-Pixel

For all channels, while viewing a stable, uniform calibration source over expected geostationary environmental conditions and calibration frequency, the imager shall have a pixel-to-pixel repeatability less than the derived NEDN.

Channels with wavelengths less than 3 microns will be characterized as if viewing a 100% albedo calibration source. Channels with wavelengths greater than 3 microns will be characterized as if viewing a 300 K temperature calibration source.

The pixel-to-pixel repeatability is calculated as follows: for each 3 row by 10 column subset of the image the row average is calculated for each row, the RMS of the row averages is then calculated and must be less than the derived NEDN.

This value is then averaged Nimage times where Nimage is the number of samples required to state at the 90% confidence level that the requirement has been met for all possible locations on the full disk.

Pixel-to-Pixel Equation disk. full on the locations possible allfor met be toappliesequation This jcolumn i, rowfor valuepixel resampled theis

i. rowfor mean row theis pixels. 30for mean theis

N

NEDN Derived image ji j jii i j ji

N j i i

P

PR

PR

where

RR

image

3.2.5.2.2 Collection-to-Collection

For each channel with a wavelength greater than 3 microns, while viewing a stable, uniform 300K temperature calibration source over expected geostationary environmental conditions and calibration frequency, the difference in calibrated

Page 19 of 50 Printed Monday, November 2, 2020

ID

GXIPORD235

GXIPORD237

GXIPORD238

GXIPORD239

GXIPORD240

GXIPORD242

GXIPORD243

Object Number

3.2.5.2.2.0-1

3.2.5.2.2.0-2

3.2.5.2.3

3.2.5.2.3.0-1

3.2.5.2.3.0-2

3.2.5.2.4

3.2.5.2.4.0-1

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD) pixel radiance between collection boundaries in a resampled image shall be less than the derived NEDN. The collection-to-collection repeatability is evaluated by computing the RMS of the difference of neighboring row means at collection boundaries for superregional images. NBoundaries is the number of boundaries required to state at the 90% confidence level that the requirement has been met.

In the resampled image, a boundary is where neighboring North/South pixels come from different collected images.

Swath-to-Swath Equation long pixels M of rowhigh pixel one a ofmean theis

NEDN Derived

,0

M i i

South sNBoundarie i

North

P M

R where

RR

sNBoundarie

3.2.5.2.3 Channel-to-Channel

For each channel with a wavelength greater than 3 microns, while viewing a stable, uniform 300K temperature calibration source over expected geostationary environmental conditions and calibration frequency, the imager shall have a channel-to-channel repeatability of less than 0.2 Kelvin. The channel-to-channel repeatability is evaluated by computing the RMS of superregional image mean differences between each channel pair, over a series of NImages. NImages is the number of images required to state at the 90% confidence level that the requirement has been met.

a Superregional image ofmean the is microns 3 an greater th swavelength pair with Channel 2, 1

Im

2.0

1 , 1

0 , 2 , 1 Im

1 , M N j i j i c r ages N r c r

T

NM

T c c where

T T ages N

K

Channel-to-Channel Equation

3.2.5.2.4 Image-to-Image

For each channel with a wavelength greater than 3 microns, while viewing a stable, uniform 300K temperature calibration source over expected geostationary environmental conditions and calibration frequency, the imager shall have an image-to-image repeatability of less than 0.2 Kelvin. The image-to-image repeatability is evaluated by computing the RMS of consecutive superregional image differences over a series of NImages for each channel. NImages is the number of images required to state at the 90% confidence level that the requirement has been met.

Page 20 of 50 Printed Monday, November 2, 2020

ID

GXIPORD244

GXIPORD246

GXIPORD247

GXIPORD248

GXIPORD250

GXIPORD251

Object Number

3.2.5.2.4.0-2

3.2.5.2.5

3.2.5.2.5.0-1

3.2.5.2.5.0-2

3.2.5.2.5.0-3

3.2.5.3

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational Requirements Document (PORD)

Superregional image a ofmean the is

1 -NImages

2.0

1 , 1

0 , 2 Im j i j i r ages N r r

P

NM

I where

I I K

Image-to-Image Equation

3.2.5.2.5 Blackbody Calibration-to-Calibration

For each channel with a wavelength greater than 3 microns, while viewing a stable, uniform 300K temperature calibration source over expected geostationary environmental conditions and calibration frequency, the imager shall have a calibration-to-calibration repeatability of less than 0.2 Kelvin. The calibration-to-calibration-repeatability is evaluated by computing the RMS of consecutive superregional image mean differences with a blackbody calibration event between the images. Ncals is the number of image pairs required to state at the 90% confidence level that the requirement has been met.

The calculation is done in radiance units and converted to temperature with a reference temperature of 300 K in the final step.

Blackbody Calibration-to-Calibration Equation

Superregional image a ofmean the is

2.0

1 , 1

0 , ji ji after

NCals r before

P

NM

I where

I I NCals

K

3.2.5.3 Coherent Noise

Page 21 of 50 Printed Monday, November 2, 2020

ID

GXIPORD252

GXIPORD256

GXIPORD257

GXIPORD258

GXIPORD259

GXIPORD260

GXIPORD261

GXIPORD262

Object Number

3.2.5.3.0-1

3.2.5.3.0-2

3.2.5.3.0-3

3.2.5.4

3.2.5.4.1

3.2.5.4.1.0-1

3.2.5.4.1.0-2

3.2.5.4.1.0-3

418-XO-GXIPORD-0024, RM Version, GEO-XO Imager (GXI) Performance and Operational…