PRD - SMBA Implementation Phase RFI.pdf

Effective Date: TBD, DRAFT Expiration Date: TBD, DRAFT

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470-SMBA-00435, Revision DRAFT LEO Programs Division, Code 470

Near Earth Orbit Network (NEON) Program Sounder for Microwave-Based

Applications (SMBA) Performance Requirements Document

(PRD)

NOAA / NASA

Goddard Space Flight Center

Greenbelt, Maryland

GSFC SMBA CMO

<Date>

DRAFT

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Near Earth Orbit Network (NEON) Program Sounder for

Microwave-Based Applications (SMBA) Performance Requirements Document (PRD)

Review/Signature/Approval Page

Prepared By:

Kenneth Yienger

Reviewed By:

Jessica Knizhnik

Approved By:

Roger Clason

Electronic Approval available on-line at: https://jpssmis.gsfc.nasa.gov/frontmenu_dsp.cfm https://jpssmis.gsfc.nasa.gov/frontmenu_dsp.cfm iii Check the LEO MIS Server at https://jpssmis.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the correct version prior to use.

Preface

This document is under NEON Program configuration control. Once this document is approved, NEON Program approved changes are handled in accordance with Class I and Class II change control requirements as described in the NEON Program Configuration Management Procedures, and changes to this document shall be made by complete revision.

Any questions should be addressed to:

NEON Program Configuration Management Office

NASA/GSFC

Code 470 Greenbelt, MD 20771 iv Check the LEO MIS Server at https://jpssmis.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the correct version prior to use.

Change History Log

Revision Effective Date Description of Changes

(Reference the CCR & CCB/ERB Approval Date) Rev. – February 7, 2023 This version incorporates 470-CCR-22-0372 which was approved by the SMBA ERB on December 22, 2022, and by the SMBA CCB on the effective date shown.

Rev. A TBD Updated Table 2.1-1, Table 4.0-1, Table 4.1-1, Section

5.6.2.4 Instrument Engineering Mode, SMBA-52 (mass), SMBA-54 (power) SMBA-55, SMBA 221, SMBA-224;

SMBA-225.

Added definition of “component” in Section 1.5.

Add new instrument requirements in Sections 4.2 Hyperspectral and 4.7.1 RFI, and 4.8.3 Scan Characteristics Editorial throughout (Reqt Id’s, formatting) v Check the LEO MIS Server at https://jpssmis.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the correct version prior to use.

Table of Deviations/Waivers [optional]

Item No. Deviation/Waiver Waiver Approved Effectivity vi Check the LEO MIS Server at https://jpssmis.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the correct version prior to use.

Table of TBDs/TBRs/TBSs

Item No.

Location Summary Individual/ Organization

Due Date

1 4.1 Table 4.1-1: NEON Program Microwave Sounder Baseline Requirements (TBS)

Instrument Provider

2 4.7 4.7.2 Striping (TBS) Instrument Provider 3 4.7 4.7.3 Inter-channel Noise

Correlation (TBS) Instrument Provider

4 4.7 4.7.4 Noise Power Spectral Density (TBS)

Instrument Provider

5 5.1 Instrument Accommodations (TBR) (Power, Heat Transfer, Uncompensated Momentum)

ISE

6 5.4.2 Table 5.4.2-1 Mission End-to-End Pointing Requirements at Instrument LOS (TBS)

Instrument Provider

7 5.6.1.4 Spacecraft Attitude/Ephemeris Estimation Packet Frequency

(TBR)

ISE

8 5.6.1.4.2 Instrument Calibration Maneuvers

(TBS)

Instrument Provider

9 5.7.1 Worst Case Launch Load (axial/lateral) (TBR)

ISE

10 7.3.1.4 Table 7.3.1.4-1 Intentional and Unintentional Radiated Electric Field Emissions Limits at the SMBA Instrument Interface, 18 to 200 GHz (TBR)

Instrument Provider

11 7.3.1.4 Table 7.3.1.4-2 SMBA Receive Sensitivity (TBR)

Instrument Provider

12 7.3.2.2 Table 7.3.2.2-1 Spacecraft Transmitter Frequency Susceptibility Test Levels (TBS)

Instrument Provider

13 7.6.3 Instrument Outgassing rate limit.

(TBS)

Instrument Provider vii Check the LEO MIS Server at https://jpssmis.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the correct version prior to use.

Table of Contents

1 INTRODUCTION

1.1 Purpose

1.2 Document Scope

1.3 NEON Program and NEON Series-1 Project Overview

1.4 The Sounder for Microwave-Based Applications

1.5 Requirements Definitions

2 APPLICABLE/REFERENCE DOCUMENTS

2.1 Applicable Documents

2.2 Reference Documents

3 GENERAL REQUIREMENTS

3.1 On-Orbit Coordinate System

3.2 Mission Time Convention

3.3 Risk Classification and Mission Assurance Requirements

4 SMBA SCIENCE REQUIREMENTS

4.1 Science Performance Requirements

4.2 Hyperspectral Capability

4.3 Calibration Accuracy

4.4 Temperature Sensitivity

4.5 Channel Dynamic Range

4.6 Channel Linearity

4.7 Noise Characteristics

4.7.1 Radio Frequency Interference Detection Capability

4.7.2 Striping (TBS)

4.7.3 Inter-channel Noise Correlation (TBS)

4.7.4 Noise Power Spectral Density (TBS)

4.8 Beam Characteristics

4.8.1 Channel Rejection

4.8.2 Gain

4.8.3 Scan Characteristics

4.9 Spectral Response Function

4.10 Calibration

5 NEON SERIES-1 SATELLITE-LEVEL REQUIREMENTS

5.1 Instrument Accommodations

5.2 Mission Orbit Requirements

5.3 Mission Lifetime, Commissioning, and Storage Requirements

5.4 Mission Data Requirements

5.4.1 Mission Data Geolocation Requirements

5.4.2 Instrument Pointing, Accuracy, and Stability Requirements

5.4.3 Instrument Timing Requirements

5.5 NEON Series-1 Project Mission Phases

5.5.1 Satellite Assembly, Integration and Test, and Ground Storage Phase

5.5.2 Pre-Launch/Launch Site Processing Phase

5.5.3 Launch and Orbit Insertion Phase

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5.5.4 Satellite Activation, Checkout, and Commissioning Phase

5.5.5 Mission Operations Phase

5.5.6 End-of-Life Decommissioning Phase

5.6 Instrument Functional Requirements

5.6.1 Typical Spacecraft Modes

5.6.1.1 Spacecraft Off Mode

5.6.1.2 Launch Mode Functional Requirements

5.6.1.3 Spacecraft Safe Modes

5.6.1.3.1 Earth-Pointing Safe Mode

5.6.1.3.2 Sun-Pointing Safe Mode

5.6.1.4 Spacecraft Engineering Mode

5.6.1.4.1 Orbit Adjust/Collision Avoidance

5.6.1.4.2 Instrument Calibration Maneuvers

5.6.1.5 Spacecraft Science Operations Mode

5.6.1.6 End-of-Mission Passivation Mode

5.6.2 Typical Instrument Modes

5.6.2.1 Instrument OFF Mode

5.6.2.2 Instrument Survival Mode

5.6.2.3 Instrument Safe Mode

5.6.2.4 Instrument Engineering Modes

5.6.2.4.1 Instrument Activation Mode

5.6.2.4.2 Instrument Diagnostic Mode

5.6.2.5 Instrument Operational Mode

5.6.3 Contingency Management

5.7 Instrument Design Requirements

5.7.1 Structural Requirements

5.7.2 Mechanism Design Requirements

5.7.2.1 Torque/Force Margins

5.7.2.2 Binding/Jamming/Seizing

5.7.2.2.1 Clearances

5.7.2.2.2 Tolerancing

5.7.2.2.3 Lubrication

5.7.2.2.3.1 Lubricant Compatibility

5.7.2.2.3.2 Lubricant Life

5.7.2.2.3.3 Bearing Lubrication

5.7.2.3 Scan Motor

5.7.2.3.1 Scan Control Capability

5.7.2.3.2 Contingency Capability

5.7.2.4 Mechanism Performance and Strength Analysis

5.7.3 Electrical Systems Requirements

5.7.4 Electromagnetic Interference (EMI) and Electromagnetic Compatibility (EMC)

Requirements

5.7.5 Thermal Control Requirements

5.7.6 Contamination Control Requirements

5.7.7 Instrument Flight Software Requirements

5.7.8 Instrument Simulator and Emulator Requirements

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6 SPACE ENVIRONMENT REQUIREMENTS

6.1 General Radiation

6.2 EMI/EMC - RF Environment

7 VERIFICATION REQUIREMENTS

7.1 Mission Requirements Verification

7.2 Electrical Functional Test Requirements

7.2.1 Electrical Interface Testing

7.2.2 Comprehensive Performance Tests (CPTs)

7.2.3 Limited Performance Tests (LPTs) and Aliveness Tests

7.2.4 NEON Series-1 Ground System Compatibility Tests (GCTs)

7.2.5 Flight Hardware Operating Time (Burn-In) and Failure Free Performance

7.3 Satellite-Level EMC/EMI Testing

7.3.1 Radiated Emissions (RE)

7.3.1.1 RE, Electric Field, Standard Bandwidth(s)

7.3.1.2 RE, Electric Field, Narrow Bandwidth(s)

7.3.1.3 Radiated Emissions, Spacecraft Transmitters

7.3.1.4 Radiated Emissions, SMBA Instrument Compatibility

7.3.2 Radiated Susceptibility (RS)

7.3.2.1 RS, Electric Field, Orbit and Launch Levels

7.3.2.2 RS, Electric Field, Satellite Transmitters

7.3.3 RF Airlink/Self-Compatibility Test

7.4 Structural and Mechanical Verification Requirements

7.4.1 Structural Loads Qualification

7.4.2 Acoustic Testing

7.4.3 Random Vibration Testing

7.4.3.1 Random Vibration After Rework

7.4.4 Sine Vibration Testing

7.4.5 Shock Testing

7.5 Mechanism and Deployment Verification

7.6 Thermal Vacuum Environmental Testing

7.6.1 Thermal Vacuum Cycling

7.6.2 Thermal Design Margin (Thermal Balance) Testing

7.6.3 Contamination/Bake-Out Requirements

8 REQUIREMENTS VERIFICATION MATRIX

8.1 General Verification Requirements

8.2 Verification Cross Reference

8.3 Definition of Verification Methods

8.3.1 Verification by Analysis

8.3.2 Verification by Inspection

8.3.3 Verification by Demonstration

8.3.4 Verification by Test

APPENDIX A ABBREVIATIONS AND ACRONYMS

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List of Figures

Figure 1.3-1. Notional NEON Series-1 Project Architecture Figure 3.1-1. On-Orbit Coordinate Systems Figure 5.4.2-1. Pointing Terminology Figure 5.4.2-2. Analysis of Geolocation Knowledge Uncertainty at Nadir Figure 5.6.1-1. Typical Spacecraft Mode Transitions Figure 5.6.1.3.1-1. Typical Spacecraft Configuration for Earth-Pointing Safe Mode Figure 5.6.1.3.2-1. Typical Spacecraft Configuration for Sun-Pointing Safe Mode Figure 5.6.1.4-1. Typical Spacecraft Configuration for Engineering Mode and Science

Operations Mode Figure 5.6.2-1. Typical Instrument Mode Transition Diagram Figure 7.4.3.1-1. Minimum Workmanship Random Vibration Test Levels Figure 7.4.5-1. Shock Response Spectrum (SRS) for Assessing Component Test Requirements

List of Tables

Table 2.1-1. Applicable Document List Table 2.2-1. Reference Documents List Table 4.0-1. Microwave Instrument Performance Capabilities Prioritization1 Table 4.1-1. NEON Program Microwave Sounder Baseline Requirements (TBS) (This table can be revised to reflect the specifics of the instrument chosen) Table 4.2-1. Hyperspectral and RFI Detection Capabilities by Band Table 5.4.2-1. Mission End-to-End Pointing Requirements at Instrument LOS[1] Table 5.6.1.4.2-1. Suggested Instrument Calibration Maneuver Requirements (TBS) Table 5.6.2-1. Instrument Mode Characterization Table 5.7.1-1. Flight Hardware Design/Analysis Factors of Safety Applied to Limit Loads [¹] [²]

Table 5.7.4-1. Instrument and Subsystem Level Test Applicability Matrix Table 5.7.7-1. Flight Processor Resource Utilization Limits Table 6.2-1. Radiated Susceptibility Levels Due to Factory/Transport, Launch Site, Launch

Vehicle, Ascent, and On-Orbit Phases Table 7.3-1. Satellite-Level EMI/EMC Test Applicability Matrix Table 7.3.1.1-1. Unintentional Radiated Electric Field Emissions, 2 MHz to 18 GHz, Standard

MIL-STD-461G Bandwidths, Orbit Mode Table 7.3.1.1-2. Radiated Electric Field Emissions, 14 kHz to 18 GHz, Standard MIL-STD-

461G Bandwidths, Launch Mode, at Separation Plane Table 7.3.1.2-1. Unintentional Radiated Electric Field Emissions, Receiver Frequencies, Narrowband (notched) MIL-STD-461G Scans (Modified Bandwidths), Orbit Mode Table 7.3.1.2-2. Radiated Electric Field Emissions, Receiver Frequencies, Narrowband MIL-

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Table 7.3.1.4-1. Intentional and Unintentional Radiated Electric Field Emissions Limits at the SMBA Instrument Interface, 18 to 200 GHz (TBR)

Table 7.3.1.4-2. SMBA Receive Sensitivity (TBR) Table 7.3.2.2-1. Spacecraft Transmitter Frequency Susceptibility Test Levels (TBS) Table 7.4-1. Structural and Mechanical Verification Test Requirements Table 7.4.3.1-1. Component Minimum Workmanship Random Vibration Test Levels

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1 INTRODUCTION

1.1 Purpose

This Sounder for Microwave-Based Applications (SMBA) Instrument Performance Requirements Document (PRD) specifies instrument-level functional, design, performance, integration, test, and delivery requirements for the instrument provider.

1.2 Document Scope

This specification establishes the requirements for the Sounder for Microwave-Based Applications (SMBA) instrument. The scope of the PRD includes all functional, design, performance, integration, test, and delivery requirements for the instrument, but does not include mission-specific accommodation and interface requirements for the instrument on the spacecraft.

The instrument provider is responsible for developing and maintaining a hierarchy of lower-tier specifications that derive and allocate requirements to subsystems and components.

1.3 NEON Program and NEON Series-1 Project Overview

The Near Earth Orbit Network (NEON) Program in the NESDIS Office of LEO Observations provides a framework to provide global measurements of earth systems. These environmental measurements will be able to support a wide variety of atmospheric, terrestrial, marine, and polar observations. The data includes the numerical weather prediction models, fire and flood models, atmospheric chemistry observations, and multiple land imagery products that have been a crucial piece of the NOAA strategic goal to create a “Climate Ready Nation” and which provide essential information to NOAA's broader environmental stewardship mission. Following the recommendations from the 2017 NOAA Satellite Observation System Architecture (NSOSA) study, the NEON Program intends to use a combination of small and medium satellite platforms in a disaggregated architecture. This approach will provide an efficient means of filling gaps quickly and taking advantage of emerging remote sensing technologies.

To execute a disaggregated LEO architecture and other NSOSA recommendations, the NEON Program plans to:

• Use industry’s significant investment of funding, expertise, and innovation in space and space systems technology.

• Deploy NOAA observation system assets where and when they are most needed, enabled by shorter development timelines and more frequent launches.

• Leverage smaller instruments, satellites, and evolving small launch vehicles; and

• Achieve greater agility to incorporate continuous advancement, using new business models and partners.

The NEON Program will accomplish these goals by continuing to leverage the multi-decadal partnership between NOAA and NASA.

The NEON Series-1 Project is an initial operational project for the NEON Program featuring the development, integration, test, launch, and science operations of the SMBA instrument – a successor to the Advanced Technology Microwave Sounder (ATMS) instrument, versions of

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which are on each of the JPSS satellites. It will allow the NEON Program to provide continuity with the existing JPSS-era microwave sounder measurements as well as leverage newer technological advances to advance the collection of hyperspectral microwave sounding data that is crucial to numerical weather prediction models.

Figure 1.3-1. Notional NEON Series-1 Project Architecture

Utilizing elements and best practices of the commercial space industry to meet federal program level requirements, the NEON Series-1 Project will demonstrate the NEON Program can provide operational hyperspectral microwave sounding observation capabilities with a small satellite that can be flexibly deployed to a variety of operational orbits. This first operational project, consisting of four individual flight missions to two distinct sun synchronous orbits (local time of ascending nodes of 1330 and 1730), will demonstrate the NEON disaggregated mission portfolio that provides the program with the flexibility of placing hyperspectral microwave sounders in either operational orbit (1330 or 1730 LTAN), at any desired launch cadence as the program needs to support hyperspectral microwave sounder needs.

NEON Series-1 Project will also leverage mission assurance practices relative to established commercial New Space missions and establish a referenceable knowledge base of rapid procurement practices that will benefit the future environmental observation missions planned in the high launch tempo NEON Program.

The NEON Series-1 Project is Class C as per NPR 8705.4, which applies the appropriate NASA management controls, systems engineering processes, mission assurance requirements and risk management processes.

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1.4 The Sounder for Microwave-Based Applications

The Sounder for Microwave-Based Applications (SMBA) instrument is the principal instrument aboard the NEON Series-1 satellite. The instrument (hereafter referred to as the 'SMBA instrument' or simply the 'instrument'), collects hyperspectral microwave radiometric data that are used to calculate the vertical distribution of temperature (T), moisture (q), and pressure in the Earth's atmosphere.

The instrument measures atmospheric radiances within the microwave range of approximately 20-300 GHz over a swath width of approximately 2,530 km from an altitude of 824 km.

Instrument data is acquired continuously, stored on-board the satellite, and subsequently downlinked to a ground network for capture, preprocessing, and routing to meteorological centers.

The instrument produces Raw Data Records (RDRs) in an uncalibrated form. Engineering, instrument telemetry, science data, radiometric, and spectral calibration data is provided to enable the RDRs to be calibrated and geolocated. In addition, diagnostic RDR data may be acquired for testing purposes. The data are sent to the NOAA Ground System where they are used as input to science algorithms that generate Temperature Data Records (TDRs), Sensor Data Records (SDRs), and Environmental Data Records (EDRs).

The instrument system performance requirements are provided in subsequent sections.

1.5 Requirements Definitions

Throughout this PRD:

a. Contractually imposed mandatory requirements are identified by “shall” statements with requirement identification numbers of the form SMBA-XXXX. Any deviation from these requirements requires approval of the Government Contracting Officer.

b. Preferred good practices are identified by “should” statements. “Should” designates performance, which is requested, but not mandatory. Noncompliance of a “should” statement does not require Government approval but shall be addressed at the earliest applicable project milestone.

c. Permission is identified by “may” or “can” statements.

d. Expected outcome or action is identified by “will” statements.

e. The term “instrument” refers to the SMBA instrument which may be constructed of one or more “components” that are individually mounted to the spacecraft. If the instrument is a single assembly, then the term “component” is synonymous with “instrument”. If not, then the term “component” is applicable to each severable unit of the instrument assembly.

f. The term “spacecraft bus” refers to the NEON Series-1 spacecraft without instruments.

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g. The term “satellite” refers to the NEON Series-1 spacecraft bus integrated with the flight instrument(s). The term “satellite” is equivalent to the term “observatory” used in other NASA and NEON Program documents.

h. The term “spacecraft” may refer to the spacecraft bus or the satellite.

i. The term “instrument provider” refers to the SMBA instrument contractor with whom the government has entered into a contract to execute the SMBA instrument Statement of Work (which is titled “Sounder for Microwave-Based Applications (SMBA) Instrument Statement of Work (SOW) (470-SMBA-00438)”) and satisfy the requirements of this

PSD.

j. The term “government” represents the appropriate NOAA and/or NASA NEON Program or NEON Series-1 Project management office or, where “the government” is indicated as providing a function for or interface to the SMBA instrument provider, the function or interface may be provided by government support services contractors.

k. The term “TBR” (to be reviewed) means that the stated information will be reviewed for appropriateness jointly by the instrument provider and the government and the information may be changed prior to final definition by the government during the course of the contract.

l. The term “TBD” (to be determined) indicates further research or analysis is needed to determine the information during the course of the contract.

m. The term “TBS” (to be supplied) information that will be supplied/specified during course of instrument’s development.

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2 APPLICABLE/REFERENCE DOCUMENTS

2.1 Applicable Documents

The applicable documents listed below are called out within individual requirements specified in the PRD. All or portions of these documents apply directly to the performance required and contain provisions that constitute requirements of this PRD. In the event of a conflict between the language in an applicable document and in this PRD, the PRD will govern.

Table 2.1-1. Applicable Document List

Document Number Revision Document Title

470-SMBA-00436 * SMBA Instrument Mission Assurance Requirements 47x-000xx * NEON Series-1 Spacecraft to SMBA Instrument Interface Control

Document 47x-000xx * NEON Series-1 Spacecraft to SMBA Instrument Mechanical

Interface Control Document 470-REF-00034 * Radiation Environment for the NEON Program ISO 14644-1 May 1, 1999 Cleanrooms and Associated Control Environments

MIL-STD-461C C

August 4, 1986 Electromagnetic Emission and Susceptibility Requirements for the Control of Electromagnetic Interference (EMI), Revision C (August 4, 1986)

MIL-STD-461G G

December 11, 2015

Requirements for the Control of Electromagnetic Interference Characteristics of Subsystems and Equipment, Revision G (December 11, 2015)

MIL-STD-462 Rev - Notice 2 from May 1, 1970

Measurement of Electromagnetic Interference Characteristics (Notice 2)

NASA-STD-2017 B Design and Development Requirements for Mechanisms NASA-STD-5001 B w/ change 3 Structural Design and Test Factors of Safety for Spaceflight

Hardware NASA-STD-5017 B Mechanism Design Requirements NASA-STD-8719.14 C NASA Process for Limiting Orbital Debris NASA-STD-8719.24 Initial with Change 1, Annex with Change 2 Jun 2012

NASA ELV Payload Safety Requirements

NPR 8715.6 B NASA Procedural Requirements for Limiting Orbital Debris ORDEM Version 3.2 Orbital Debris Engineering Model MEM Version 3.0 Meteoroid Environment Model

* See contract's applicable documents List for the current revision

2.2 Reference Documents

The reference documents listed below are referred to within the PRD and contain information relating to the work required. The documents do not contain provisions that constitute requirements of this PRD, but rather serve to amplify or clarify the requirements.

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Table 2.2-1. Reference Documents List

Document Number Revision Document Title 470-SMBA-00438 * NEON Series-1 SMBA Implementation Phase Statement of

Work (SOW) 470-SMBA-00439 * NEON Series-1 SMBA Implementation Phase Contract Data

Requirements List (CDRL) 472-00228 * JPSS Flight Project Contamination Control Plan ASTM E595 Revision dated

5/14/2021 Standard Test Method for Total Mass Loss and Collected Volatile Condensable Materials from Outgassing in a Vacuum Environment

CCSDS 301.0-B-4 November 2010 Consultative Committee for Space Data Systems (CCSDS) Time Code Formats Standard

GSFC-STD-7000 B General Environmental Verification Standard (GEVS) for GSFC Flight Programs and Projects

IEST-STD-CC1246 E Product Cleanliness Levels and Contamination Control Program

JSC-CR-06-070 August 2006 Space Vehicle RF Environments NPR 8705.4 4/29/2021 Risk Classification for NASA Payloads http://outgassing.nasa.gov Outgassing Data for Selecting Spacecraft Materials

* See contract's applicable documents List for the current revision http://outgassing.nasa.gov/

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3 GENERAL REQUIREMENTS

3.1 On-Orbit Coordinate System

NEON Series-1 satellite's on-orbit coordinate system uses a right-hand, orthogonal, body-fixed XYZ coordinate system as follows (see Figure 3.1-1): the +Z-axis is downward towards geodetic nadir, the Y-axis is along the orbit normal plane (+Y is opposite the orbital angular momentum), and the X-axis is along the spacecraft velocity vector (+X toward the direction of spacecraft travel).

Figure 3.1-1. On-Orbit Coordinate Systems

NEON Series-1 Project uses J2000-referenced orbital elements for attitude knowledge and the WGS84 geodetic reference system for environmental data geolocation.

The instrument should use the international system of units, Système Internationale (SI), unless precluded by design or manufacturing heritage. All interface documents should provide units in SI and English. The primary (as-designed) units should be displayed above the converted units with the latter in parentheses.

3.2 Mission Time Convention

SMBA-1 The instrument shall time stamp packets in the secondary header using

Coordinated Universal Time (UTC), including the leap-second convention, also known as CCSDS Day Segmented Time Code (CCSDS 301.0-B-4), for all instrument telemetry while the instrument processor is running.

Note: Telemetry frames that are generated by hardware during ascent or processor down time may format the time stamp using CCSDS Unsegmented Time Code(CCSDS 301.0-B-4).

3.3 Risk Classification and Mission Assurance Requirements

The instrument risk classification is Class C, as per NPR 8705.4, Risk Classification for NASA Payloads.

SMBA-2 The instrument provider shall comply with SMBA Instrument Mission

Assurance Requirements (470-SMBA-00436).

Safety design requirements and requirements for the control of catastrophic and critical failures are contained in SMBA Instrument Mission Assurance Requirements (470-SMBA-00436).

The instrument and its ground support equipment used at the launch site comply with the NASA- STD-8719.24 NASA ELV Payload Safety Requirements or other applicable range safety

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documentation contained in SMBA Instrument Mission Assurance Requirements (470-SMBA- 00436).

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4 SMBA SCIENCE REQUIREMENTS

To provide guidance on microwave sounder instrument performance capabilities, Table 4.0-1 details the relative prioritization of the various performance factors associated with the next generation hyperspectral microwave instrument.

Table 4.0-1. Microwave Instrument Performance Capabilities Prioritization1

Factor Order

Performance Factor Performance Target

1 Channels for direct Temperature Sounding

≥ 20 channels around 50-60 GHz and ≥ 10 channels around 118 GHz

See Table 4.2-1 2 Channels for direct

Moisture sounding ≥ 10 Channels or more around 183 GHz

See Table 4.2-1 3 Window channels; channels for cloud, precipitation, ice detection for direct all-sky assimilation and NWP QC

Channels at 23.8, 31.4, 88.2, 165.5, and 229 GHz. See Table 4.2-1

Plus additional aspirational channels:

a) At least four channels at the below frequencies, listed in priority order: (i) 22- 23 GHz (highest priority), (ii) 31-37 GHz,

(iii) 89 GHz, and (iv) 18 GHz (lowest priority) and

b) 200-325 GHz for cloud/precipitation detection and surface signal distinction

4 Spatial coverage (daily global) 95% Global Coverage

5 Noise Level (NEDT) for Temperature sounding channels See Table 4.1-1

6 Noise level (NEDT) for Moisture sounding channels See Table 4.1-1

7 Spatial horizontal resolution (at nadir)

32 km (T) 16 km (q)

8 Spatial sampling Contiguous footprints (or better) 9 Scan geometry Cross track 10 Polarization Single linear polarization 11 ATMS Channels Continuity Yes, for similar channels 12 Calibration accuracy See Table 4.1-1

1 Systems performance Assessment Team (SAT), Boukabara, S.(chair), Gallagher, F.(co-chair).

[Scientific Guidance for potential study and design of Microwave Sounder (for SounderSat and GEO-XO)]. Retrieved from NOAA/NESDIS Center for Satellite Applications and Research.

September 17, 2020.

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4.1 Science Performance Requirements

Table 4.1-1. NEON Program Microwave Sounder Baseline Requirements (TBS) (This table can be revised to reflect the specifics of the instrument chosen)

Priority Center Frequency (1) (GHz)

Center Frequency Stability(2)

(MHz)

Channel Bandwidth

(3) (GHz)

Calibration Accuracy

(K)

Temperature Sensitivity

NEDT

@300K (K)

(III) (IV) 23.8 5 0.27 0.5 0.24

(III) (IV) 31.4 5 0.18 0.5 0.28

50.3 4 0.18 0.5 0.33

51.76 4 0.4 0.5 0.22

52.8 4 0.4 0.5 0.22

53.596 ± 0.115 3 0.17 0.5 0.24

54.4 2 0.4 0.5 0.22

(I) 54.94 3 0.4 0.5 0.22

(IV) 55.5 3 0.33 0.5 0.30

57.290344 0.3 0.33 0.5 0.35

57.290344 ± 0.217 0.4 0.078 0.5 0.45

57.290344 ± 0.3222 ± 0.048 0.9 0.036 0.5 0.50

57.290344 ± 0.322 ± 0.022 0.4 0.016 0.5 0.75

57.290344 ± 0.322 ± 0.010 0.4 0.008 0.5 1.00

57.290344 ± 0.3222 ± 0.0045 0.5 0.003 0.5 1.60

(III) (IV) 88.2 18 2 0.5 0.20

114.50 1 1 0.5 0.30

115.95 1 0.8 0.5 0.30

116.65 1 0.6 0.5 0.30

(I) 117.25 1 0.6 0.5 0.30

117.80 1 0.5 0.5 0.40

118.24 1 0.38 0.5 0.40

118.58 1 0.30 0.5 0.50

(III) 165.5 22 3 0.4 0.30

183.31 ± 7 14 2 0.4 0.26

(II) 183.31 ± 4.5 14 2 0.4 0.26

(IV) 183.31 ± 3 16 1 0.4 0.36

183.31 ± 1.8 10 1 0.4 0.36

183.31 ± 1 9 0.5 0.4 0.50

(III) 229 22 2 0.5 0.36

(1) Number of passbands per channel, listed in “Center Frequency” column, is maximum allowed. Fewer passbands may be used, provided the Temperature Sensitivity requirements are met. For example, Table 4.1- 1 lists two passbands centered at (183.31 + 7) = 190.31 GHz and (183.31-7) = 176.31 GHz. The channel may be implemented using only one of these passbands, provided the temperature sensitivity value of no greater than 0.3 K is achieved.

(2) Channel center frequency stability is defined as the maximum deviation from the channel center frequency for both long-term and short-term periods over the operational life of the instrument.

(3) Channel bandwidth is defined as the spectral width between the half-power points per passband.

(I) Performance Capability Priority 1: Temperature Sounding (II) Performance Capability Priority 2: Moisture Sounding (III) Performance Capability Priority 3: Additional Channels (IV) Performance Capability Priority 11: ATMS Channel Continuity

SMBA-3 SMBA instrument shall provide the channels at the nominal center frequencies identified in Table 4.1-1.

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SMBA-4 The center frequency stability of the channels shall be less than or equal to the values listed in Table 4.1-1.

SMBA-5 The bandwidths of the channels shall be less than or equal to the values listed in Table 4.1-1.

4.2 Hyperspectral Capability

Hyperspectral capability indicates an increased number of channels for a given frequency range.

SMBA-6 Hyperspectral capability shall be provided for all spectral bands identified in

Table 4.2-1.

Table 4.2-1. Hyperspectral and RFI Detection Capabilities by Band

Frequency Bands1 Hyperspectral Capability RFI Detection Capability K (23.8 GHz) Required4 Required5 Ka (31.4 GHz) Required4 Required5 V (50-60 GHz) Required2 Required5 W (88.2 GHz) Not Required (Aspirational) Required6

F (114.5-118.58 GHz) Required2 Not Required (Aspirational) G (165 GHz) Not Required (Aspirational) Not Required (Aspirational)

G (183.31 GHz) Required3 Not Required (Aspirational) Y (229 GHz) Not Required (Aspirational) Not Required (Aspirational)

Note 1: Center frequencies taken from Table 4.1.1 are notional. Provider may propose alternatives in band range.

Note 2: Capability required for Temperature Sounding (Table 4.0-1 Factor 1) for continuous operational use.

Note 3: Capability required for Moisture Sounding (Table 4.0-1 Factor 2) for continuous operational use.

Note 4: Capability required for Window Channels (Table 4.0-1 Factor 3) for continuous operational use.

Note 5: RFI detection capability required for continuous operational use.

Note 6: RFI detection capability required for diagnostic purposes only.

SMBA-7 NEDT performance of a hyperspectral design shall be equivalent to that of a non-hyperspectral design in the same frequency range.

4.3 Calibration Accuracy

Calibration accuracy is defined as the difference (error) between the brightness temperature inferred from the microwave radiometer (referred to the antenna collecting aperture) and the actual brightness temperature of a calibration reference. Calibration accuracy is the average error over a time scale longer than 24 hours.

Note:

1. A calibration reference is defined as an element that provides a signal that corresponds to a known brightness temperature. It can be a physical thing (like a blackbody; ex: on-board target or cold space). A noise diode is also an example of a reference.

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2. Traditional radiometers have used two-point calibration methodology: cold space for the cold reference temperature and an on-board target for the warm reference temperature. The instrument design is not constrained to this methodology or calibration reference types. Other types of calibration references exist such as noise diodes and cold FETs.

3. Proposed references that are also standards (in the National Institute of Standards and Technology (NIST) sense) must include a description of the traceability plan that enables them to be a standard, along with an estimate of the (absolute) accuracy.

Overall accuracy includes uncertainties due to (1) errors contained in the laboratory tests and the test equipment, (2) the transition from the laboratory simulated cold calibration reference to the on-orbit cold calibration reference, and (3) emissions from the spacecraft and other instruments intercepting the near fields of the radiometer antenna(s).

Note: Corrections to the data are based on the instrument design and are becoming increasingly important as demands for accuracy increase. The instrument provider should have a sufficient understanding of how to make these corrections and determine the residual error. The residual errors contribute to calibration accuracy.

SMBA-8 The calibration accuracy of the channels shall be less than or equal to the values listed in Table 4.1-1.

SMBA-9 Overall accuracy shall include uncertainties caused by time-dependent degradation of the reference targets.

SMBA-10 Calibration accuracy predictions shall be computed as the sum of static (bias) errors and the root-sum-square of the standard deviations of dynamic (time-variable) errors, for worst case environmental conditions.

4.4 Temperature Sensitivity

Temperature sensitivity (noise equivalent delta temperature or NEDT) is defined as the standard deviation of the radiometer output in kelvins (K) brightness temperature incident at the antenna collecting aperture when the antenna is viewing a 300 K uniform and stable target.

SMBA-11 The temperature sensitivity of the channels shall be less than or equal to the baseline values listed in Table 4.1-1.

SMBA-12 The brightness temperature measurement of an Earth scene or calibration reference shall be independent of any previous measurements.

4.5 Channel Dynamic Range

SMBA-13 The dynamic range of the radiometer system shall be sufficient to cover the expected range of Earth scene brightness temperatures as well as calibration references.

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4.6 Channel Linearity

Nonlinearity is usually defined as the departure from the expected response of an ideal linear radiometer. The “residual nonlinearity” is defined as the residual error after applying a correction for the non-linearity.

SMBA-14 The residual nonlinearity shall be less than or equal to 0.1 K for all channels.

4.7 Noise Characteristics

4.7.1 Radio Frequency Interference Detection Capability

SMBA-15 Detection of Radio Frequency Interference (RFI) by man-made signals that impact operational data products, shall be provided for all spectral bands identified in Table 4.2-1.

SMBA-16 During science operations, instrument shall be capable of RFI detection simultaneously with science data collection.

SMBA-17 During diagnostic activities (i.e. to assess RFI detection algorithms), instrument shall be capable of collecting, storing, and relaying to ground raw spectral data used for RFI detection.

4.7.2 Striping (TBS)

Differences in the along-scan vs. along-track noise characteristics can lead to undesirable linear artifacts in images – i.e., striping.

Note: Instrument provider to propose striping requirement (or multiple requirements).

4.7.3 Inter-channel Noise Correlation (TBS)

Typically, inter-channel noise correlation is measured by correlating the noise signal in one channel to the concurrent noise signal in another channel while viewing the same Earth scene or calibration reference.

Note: Instrument provider to propose inter-channel noise correlation requirement(s).

4.7.4 Noise Power Spectral Density (TBS)

The noise power spectral density is an important characteristic of all radiometer channels relating quantities like NEDT, 1/f noise, gain variations, and striping. There are different ways that one might specify requirements related to noise power spectral density.

Note: Instrument provider to propose noise power spectral density requirement (or multiple requirements).

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4.8 Beam Characteristics

Each channel of the instrument is considered to form a beam. In the following sections, if only one beam is discussed it is inferred to represent any and all beams.

The term “Beam Position” means the position of a “Beam-Center,” which is defined as the position of the beam (electrical boresight) at the mid-point of the integration time.

Beamwidth is defined as the width between the half-power points. The beam electrical boresight is defined as the mid-point between the half-power points of the instantaneous antenna pattern.

SMBA-18 The beamwidth in any plane containing the main beam axis (electrical boresight axis) shall be within plus or minus 10% of the nominal beam width.

SMBA-19 Instrument antenna beam efficiency shall be no less than 95.0% at all frequencies and all beam positions.

SMBA-20 Antenna characterization measurements/patterns shall be provided for each instrument channel.

SMBA-21 All main beam axes of the instrument shall be coincidental (i.e., they will be pointing in the same direction, subject to the pointing accuracy requirements) at the same time for any given beam position.

4.8.1 Channel Rejection

SMBA-22 Each channel shall have a gain that is no greater than 40 dB below the band-center value for all frequencies outside of a band ±0.70 times the specified half-power bandwidths.

SMBA-23 All channels that use upper and lower mixer sideband signals shall employ stop-bands to reduce local oscillator noise to levels compatible with meeting the sensitivity and the calibration accuracy requirements.

4.8.2 Gain

Passband gain is defined as the overall gain of the instrument from the antenna aperture to the instrument output, averaged over the passband bandwidth.

SMBA-24 The gains of all passbands within any one channel shall be within ±1 dB.

SMBA-25 The band center gain of each passband shall vary no more than ±2 dB over the operating temperature range and life of the instrument.

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4.8.3 Scan Characteristics

SMBA-26 Instrument shall provide contiguous spatial sampling (both along-track and cross-track) when operated in the mission orbit.

SMBA-27 Instrument shall provide a minimum 95% global coverage when operated in the mission orbit.

SMBA-28 Instrument shall have a minimum spatial horizontal resolution (at nadir) of 32 km (T) and 16 km (q) when operated in the mission orbit.

SMBA-29 The instrument shall scan and position the sensor boresight to enable measurement of scene radiance at specified locations.

SMBA-30 The instrument shall synchronize its scan start time with a timing signal it receives from the spacecraft command and telemetry (C&T) bus.

SMBA-31 The time offset from the rising edge of the spacecraft timing signal to the start of beam position number one of the instrument scan shall have an accuracy of ±1 msec.

4.9 Spectral Response Function

The Spectral Response Function (SRF) is defined as the one-to-one mapping between the end-to-end gain values (from the antenna aperture through the detector output) and the RF frequencies of radiation relevant to each channel. SRF's are created via a combination of measurement and analysis. For a channel having multiple pass bands, the SRF of each passband is unique and must be independently ascertained.

SRFs are used to generate: (1) Band absorption coefficients for radiative transfer models used by environmental retrievals algorithms and numerical weather prediction (NWP) models. NWP models continue to require more accurate SRF measurements. (2) Band conversion coefficients in the SDR algorithm that calculate warm/cold target radiance from their physical temperatures and earth spectral brightness temperature from earth radiance.

SMBA-32 Through a combination of measurement and analysis, SRFs shall be provided for each channel of the instrument.

4.10 Calibration

SMBA-33 Instrument shall perform in-flight calibration for all channels.

SMBA-34 Ground calibration testing and analyses shall be performed to demonstrate that the instrument, when used in its orbital configuration, complies with the accuracy requirements.

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SMBA-35 Instrument shall be designed such that the ground calibration needs to be performed only once for each delivered instrument. No ground calibration shall be required after prolonged storage before launch.

Note: Requirements SMBA-36 through SMBA-49 are reserved for future instrument science requirements pertaining to specific implementation approaches.

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5 NEON SERIES-1 SATELLITE-LEVEL REQUIREMENTS

The following paragraphs contain requirements extracted from the NEON Series-1 Project-level requirements documentation and are directly traceable to NOAA's Mission Requirements.

5.1 Instrument Accommodations

SMBA-50 The instrument shall comply with the accommodation requirements, in accordance with the requirements delineated herein and the Spacecraft-to- SMBA Instrument ICD (47x-000xx).

SMBA-51 The instrument shall define and maintain static and dynamic clearances to the respective instrument envelope(s), define/maintain the instrument operational, calibration, and thermal field-of-views, and define integration and test target accommodations in the Spacecraft-to-SMBA Instrument MICD (47x-000xx).

SMBA-52 The initial mass allocation of the instrument will be 150 kg inclusive of instrument margin. The specific mass properties shall be specified in the Spacecraft-to-SMBA Instrument ICD (47x-000xx).

SMBA-53 The instrument shall be compliant with the launch vehicle (ELV) mechanical, electrical, and environmental requirements and constraints delineated herein and the specified in the Spacecraft-to-SMBA Instrument ICD (47x-000xx).

SMBA-54 The specific orbital average power (OAP), survival, and peak power needs

(inclusive of margin) of the instrument shall be specified in the Spacecraft-to- SMBA Instrument ICD (47x-000xx).

Note: The initial target for the OAP, inclusive of margin, is 275W (TBR), however this value will be superseded as the ICD is developed.

SMBA-55 While an adiabatic interface is preferred, the initial allowable heat transfer to the spacecraft during science operations is NTE 100 W at an interface temperature of 25 °C (TBR). The specific thermal interface needs (inclusive of margin) of the instrument shall be specified in the Spacecraft-to-SMBA Instrument ICD (47x-000xx).

SMBA-56 The Instrument shall not exceed an uncompensated momentum contribution of

±0.5 N-m-sec per axis (TBS). The specific level of on-orbit disturbances induced to the spacecraft across the instrument-to-spacecraft mounting interface shall be specified in the Spacecraft-to-SMBA Instrument ICD (47x- 000xx).

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5.2 Mission Orbit Requirements

SMBA-57 The instrument shall operate for the mission lifetime in a polar sun-synchronous orbit with the following characteristics:

Nominal Altitude: 824 km +/- 17 km Nominal Inclination: 98.71 degrees +/- 0.10 degrees Ground Track Repeatability Accuracy: +/- 20 km at the equator Ground Track Repeat Cycle: 16 days

SMBA-58 The instrument shall operate for the mission lifetime in the polar sun-synchronous orbit defined above when deployed/maintained orbit in either of the following local time of the ascending nodes (LTANs):

Nominal Ascending Equator Crossing Time: 1330 (local time) +/- 10 minutes or Nominal Ascending Equator Crossing Time: 1730 (local time) +/- 10 minutes

5.3 Mission Lifetime, Commissioning, and Storage Requirements SMBA-59 The instrument shall be designed for a mission lifetime of 5 years from completion of on-orbit commissioning.

SMBA-60 The instrument shall be capable of a 10-year ground storage period that includes routine maintenance and monitoring activities to ensure no loss of functional capabilities.

SMBA-61 The instrument shall be capable of being placed in a ground storage state that requires minimal intervention by personnel for up to 30-day periods.

5.4 Mission Data Requirements

The spacecraft C&DH subsystem collects instrument health & status telemetry, instrument memory dump, and mission data packets through the command & data interface. The C&DH subsystem multiplexes these packets and attaches appropriate protocol for downlink and storage.

The need for following functions will be determined jointly by the instrument and spacecraft providers and defined in the applicable instrument ICD.

a. Spacecraft-to-Instrument transfers consisting of real-time ground commands, stored commands, memory loads, state of health indications, and auxiliary data (e.g., time code).

b. Instrument-to-Spacecraft transfers consisting of, for example, mission data (including auxiliary data received from the spacecraft), instrument health and status telemetry, indication of instrument mode transitions, instrument diagnostic data, memory dumps, and Survival Mode temperatures (not part of the data bus).

The instrument average data rate is defined to be the total data transmitted for one orbit divided by the orbit period. The instrument peak data rate is defined as the maximum data volume divided by the collection period.

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SMBA-62 The Instrument average/peak data rates per instrument mode shall be specified in the Spacecraft-to-SMBA Instrument ICD (47x-000xx).

SMBA-63 Receipt of individual instrument commands shall be verifiable via Spacecraft health and status telemetry.

5.4.1 Mission Data Geolocation Requirements

SMBA-64 The known geolocation of the instrument boresight, referenced to the center of the effective field of view for any channel, shall be within 1.50 km (3 sigma), at nadir, on the WGS84 reference ellipsoid, at any time during nominal operations.

5.4.2 Instrument Pointing, Accuracy, and Stability Requirements

Figure 5.4.2-1. Pointing Terminology

Pointing terminology definitions are illustrated in Figure 5.4.2-1 and are defined as follows for each spacecraft axis:

• Pointing Knowledge - The angle between the actual pointing direction and the estimated pointing direction.

• Pointing Accuracy (Pointing Control) - The angle between the actual pointing direction and the desired pointing direction.

• Pointing Stability - The peak-to-peak variation in the actual pointing direction over a time interval.

• Accuracy and Knowledge terms consist of three error categories:

i. Bias: errors that remain constant over the duration of the mission.

ii. Drift: A long term variation of pointing direction.

iii. Jitter: A short term variation of the pointing direction.

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Static Errors - Errors that stay constant over mission time. Bias errors are static errors.

• Dynamic Errors - Errors that vary over time. Drift and Jitter errors are dynamic errors.

• Pointing Stability is due to dynamic error sources Drift and Jitter.

• 3 Sigma - A set of values is considered to meet a 3-sigma requirement if no fewer than

99.73% of the values are within the specified limits of the…