Amnt 24 - SMBA PRD Rev E.pdf

Effective Date: March 11, 2026 Expiration Date: March 11, 2031

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NS1-SMBA-REQ-0001, Revision E

Near Earth Orbit Network Series-1 Project, Code 473

Near Earth Orbit Network

Series-1 Project

Sounder for Microwave-Based Applications

Performance Requirements Document

Goddard Space Flight Center Greenbelt, Maryland

NOAA/NASA

GSFC NEON Series-1 CMO

RELEASED

NS1 SMBA PRD

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Near Earth Orbit Network Series-1 Project

Sounder for Microwave-Based Applications Performance Requirements Document

Review/Signature/Approval Page

Prepared by:

Christopher Anders Mission Systems Engineer NASA Goddard Space Flight Center

Approved by:

Jessica Knizhnik SMBA Instrument Manager NASA Goddard Space Flight Center

Risha George NEON Series-1 Project Manager NASA Goddard Space Flight Center

Electronic Approval available on-line at:

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Preface

This document is under NEON Series-1 (NS1) Project configuration control. Once this document is approved, NS1 approved changes are handled in accordance with Class I and Class II change control requirements as described in the Low Earth Orbit (LEO) Programs Division (LPD) Programs and Projects Configuration Management Procedure (CMP), and changes to this document shall be made by complete revision.

Any questions should be addressed to:

LEO/NEON Configuration Management Office

NASA/GSFC

Code 473 Greenbelt, MD 20771 iv Check the LPD TDMS Server at https://ipdtdms.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 Revision – 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 February 7, 2023.

Revision A December 20, 2024 This version incorporates 470-CCR-24-0402 which was approved by the SMBA ERB on March 20, 2024, and incorporates NS1-CCR-0001 by the NS1 SMBA CCB on the effective date shown.

The Document number has changed from 473-SMBA- RQMT-00004 to NS1-SMA-REQ-0001 as the document has transferred from the Management Information System (MIS) to the Technical Data Management System

(TDMS).

The Document name has changed from SMBA Instrument Performance Specification Document (PSD) to SMBA Instrument Performance Requirements Document (PRD).

Revised the following:

Requirement identifiers and numbering, Section 1.0 and its subsections, Section 4.0 and its subsections, Sections 5.1, 5.4, 5.5, 5.6, 5.7, Section 7 and its subsections & Section 8.2.

Added Table 6.2-2.

Moved Acronym List from Appendix A to Appendix B.

Added Appendix A VCRM.

Updated the following:

Tables 2.1-1, Table 2.2-1, Section 3.1, Figure 3.1-1 Table 6.2-1, & Acronym List

Editorial changes throughout.

Revision B April 17, 2025 This version incorporates NS1-CCR-0009 & NS1-CCR- 0011 which was approved by the NS1 SMBA CCB on the effective date shown.

Figure 5.4.2-1 Pointing Terminology: FROM: Accuracy (Control) TO Accuracy v Check the LPD TDMS Server at https://ipdtdms.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the correct version prior to use.

Pointing Terminology definitions FROM Pointing Accuracy (Pointing Control) TO Pointing Accuracy Table 5.4.2-1 End-to-End Pointing Knowledge FROM +/-290 arcsec 3sigma TO +/-265 arcsec 3 sigma Table 5.4.2-1 Spacecraft Pointing Knowledge FROM +/- 75arcsec 3sigma TO +/-112 arcsec 3sigma

Editorial change all instances of climate to weather.

Revision C August 19, 2025 This version incorporates NS1-CCR-0012 which was approved by the NS1 SMBA CCB on the effective date shown.

Update to the PRD in response to contract-type change to Draft SMBA RFP and the de-classification of the SMBA Instrument.

The change in procurement strategy has eliminated the IMAR as a stand-alone document. Critical portions of the IMAR are ingested into the SOW and PRD. This CCR incorporates mission assurance design requirements into the PRD and points to SOW sections for other mission assurance requirements.

This CCR removes the SMBA instrument classification of Class C and replaces it with a customized risk posture statement.

This CCR clarifies and reduces the number of requirements that are to be verified at Satellite level by moving requirements for Aliveness testing, LPTs, CPTs, and GPTs to the SOW.

This CCR clarifies requirements about science performance, flight Software soft reset, orbital debris, and radiation. It also updates Section 7 subsection titles and the acronym list.

This CCR adds a new Spacecraft-to-Instrument command & data transfer interface requirement.

Editorial changes throughout.

Revision D January 15, 2026 This version incorporates NS1-CCR-0015 which was approved by the NS1 SMBA CCB on the effective date shown.

Updates to the SMBA PRD are in response to a) industry partner responses to Draft RFP posted 4/18/2025 (NS1- SMBA-REQ-0001 Rev. B) and to Draft RFP Update posted 9/5/2025 (NS1-SMBA-REQ-0001 Rev. C); b) vi Check the LPD TDMS Server at https://ipdtdms.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the correct version prior to use.

internal NASA technical discussions; and c) NASA program and project changes

This CCR affect all sections of the PRD. Major performance, function, and test requirement revisions are as follows:

Relaxed the V-band narrowest hyperspectral resolution to only be around the peaks of the oxygen absorption spectrum (Table 4.1-2).

No longer requiring heritage channels in unprotected spectrum (Table 4.1-3) Removed 51.76 GHz (ATMS Ch 4) and modified lowest F-Band channel from 114.5 GHz to 114.75 GHz Added heritage channels to cover all of MWS channels (Table 4.1-3), which are 53.246±0.08 GHz (MWS Ch 5), 53.948±0.081 GHz (MWS Ch 7), and 89 GHz (MWS 17) Added beam polarization requirements to heritage changes (Table 4.1-3) and all SMBA channels (Section 4.8.1) Refined the aspects of the RFI detection capability that are required to be reprogrammable (SMBA-7) Requiring RFI detection packet instead of binary flag

(SMBA-13, SMBA-14)

Removed RFI metrics requirement, since metrics will be computed by NOAA Ground System (NGS) Aligned System Calibration Uncertainty definition, contributors, and accounting with NIST, BIPM, and JPSS to allow SMBA designers freedom to develop their own calibration uncertainty, accuracy, precision without bias towards a particular design (Section 4.3, Table 4.1-4) Redefined Radiometric Sensitivity (NEDT) as having two contributions: white thermal noise and 1/f noise (Section 4.4, Section 4.7, Table 4.1-4) and allowing the white thermal noise contribution to be scalable for bandwidth and integration time.

Deleted vertical reporting interval requirement (old SMBA-43) and agreed with industry partners that it is out of scope for the instrument Resolved the TBDs for SRF requirements (Section 4.9) Storage period from 10 years to 13 years (SMBA-109) Instrument storage maintenance period from 30days to 12 months (SMBA-110) Satellite storage maintenance period from 30days to 12 months (SMBA-118) vii Check the LPD TDMS Server at https://ipdtdms.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the correct version prior to use.

Added instrument fundamental resonant frequency requirement (> 100 Hz) due to varying loads applied by different Flight Elements (SMBA-149) Bus voltage requirement became a “should” statement to avoid driving instrument design (SMBA-177) EMI/EMC Testing no longer requires CS116 test due to no identified mechanism for this threat at the satellite level Rescoped the required TVAC cycles from 12 cycles before launch to 8 cycles before instrument delivery

(SMBA-257)

Relaxed TVAC thermal balance testing of all units to only requiring testing for FM1 and any flight units with design changes that affect thermal performance (SMBA- 268)

Other changes clarify the PRD requirement set and do not significantly change the PRD intent (e.g., revising requirement language, adding context, restructuring sections. and moving requirements to SOW/CDRL).

The requirements are renumbered in sequential order.

Revision E March 11, 2026 This version incorporates NS1-CCR-0018 which was approved by the NS1 SMBA CCB on the effective date shown.

Updates to the SMBA PRD Rev E are in response to a) industry partner responses to Industry Day 1/21/2026, where changes from NS1-SMBA-REQ-0001 Rev. C to Rev. D were summarized; b) internal NASA technical discussions; and c) NASA program and project changes .

This CCR affects Section 4 and Section 6 of the PRD.

Major requirement revisions are summarized as follows:

Extended the J-band range to include up to the protected spectrum up to 238 GHz and it aligns with Table 6.2-2 RS to In-band transmitters which requires analysis up to 238 GHz.

Relaxed the V-band narrowest hyperspectral resolution requirement to be around the two heritage channel absorption peaks with an objective to extend the narrow viii Check the LPD TDMS Server at https://ipdtdms.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the correct version prior to use.

resolution to additional absorption peaks as design permits. (Table 4.1-2).

Removed the linear polarization direction for heritage channels (Table 4.1-3 and Rev D SMBA-35).

Modified radiometric sensitivity requirements by adding NEDT requirement for heritage channels (SMBA-3, Table 4.1-3 & notes, Section 4.4 text) and adjusting Thermal Noise Contribution to NEDT values (Table 4.1- 4 & notes).

Modified text and added Equation 6 for 1/f noise ratio computation. (Section 4.7)

Relaxed SRF requirements (Section 4.9) to align with test equipment capabilities.

Updated Table 6.2-1 & notes, SMBA-188, SMBA-189, and SMBA-190 to address instrument component survival at the Launch Site and instrument operate-through exposures from external transmitters while at the Launch Site & On-Orbit. Launch Site includes Factory, Transport, PPF, Launch Vehicle, and Ascent. Reduced upper end of spectrum to be tested and/or analyzed from 325 GHz to 238 GHz to align with Table 4.1-1.

Changed TBS to TBD for Table 6.2-2 for spectrum where the instrument may be sensitive in unprotected spectrum and may be exposed to external transmitters.

Updated Appendix B Acronyms

The requirements and equations are renumbered in sequential order.

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Table of Deviations/Waivers

Item No. Deviation/Waiver Waiver Approved Effectivity x Check the LPD TDMS Server at https://ipdtdms.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 2.1

Table 2.1-1 Applicable Document List

- NS1-SMBA-xxx-xxxx - NEON Series-1 Spacecraft to SMBA Instrument Interface Control Document

(TBS)

Instrument Provider

CDR

2 2.1

Table 2.1-1 Applicable Document List

- NS1-SMBA-xxx-xxxx - NEON Series-1 Spacecraft to SMBA Instrument Mechanical Interface Control Document (TBS)

Instrument Provider

CDR

3 4.8.4

SMBA-41 Channels shall have peak-to-peak gain variation within each passband no greater than 1.0 dB (TBR) for K, Ka, and V bands, 1.5 dB (TBR) for W, F, D, G, and J bands.

ISE

PDR

4 4.8.5 SMBA-47 The total scan period shall be TBS seconds ±TBS msec.

Instrument Provider

PDR

5 5.1

SMBA-104 Allowable heat transfer to the spacecraft during science operations is not to exceed 175 W (TBR) at an interface temperature of

+15 °C (TBR).

ISE

CDR

+ 60 days

6 5.1 SMBA-105 Uncompensated momentum contribution of ±0.3 N-m-sec per axis (TBR).

ISE

CDR

+ 60 days

7 5.4

SMBA-112 The initial data rate allocations of the instrument shall not exceed 2 Mbps orbital average and not exceed 10 Mbps peak (TBR).

ISE

CDR

+ 60 days

8 5.4.2

Table 5.4.2-1 Mission End-to-End Pointing Requirements: Pointing Accuracy (TBR), Pointing Knowledge

(TBR)

ISE

CDR

+ 60 days

9 5.6.1.4

Spacecraft ECI to spacecraft Control Frame and/or a time-tagged spacecraft ephemeris (ECEF) with a minimum frequency of 8 Hz (TBR) if required by the instrument to meet performance requirements.

ISE

CDR

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10 5.6.1 Table 5.6.1-5 Suggested Instrument Calibration Maneuver Requirements (TBS) and SMBA-125

Instrument Provider

CDR

+ 60 days

11 5.7.2 SMBA-151 Worst case expected launch load of 15 g independently in each axis (TBR).

ISE

CDR

+ 60 days

12 5.7.3.3.1

SMBA-169 Open loop gain margin no less than 12 dB within ±10% of structural mode frequencies, and no less than 6 dB at other frequencies.

(TBR)

ISE

CDR

+ 60 days

13 6.2

Table 6.2-1 Radiated Susceptibility Levels Due to Factory/Transport, Launch Site, Launch Vehicle, Ascent, and On-Orbit Phases (TBR), values (TBD/TBR), Note [6] (TBR)

ISE

PER

14 6.2

Table 6.2-2 Radiated Susceptibility Levels Due to In-Band Sources in On- Orbit Phases (TBD/TBR/TBS) and values (TBD/TBR/TBS)

ISE

Instrument Provider

PER

15 7.3.2 Table 7.3.2-1 Spacecraft Transmitter Frequency Susceptibility Test Levels (TBD/TBR) and values (TBD/TBR)

ISE

Instrument Provider

PER

16 7.3.2.3

Table 7.3.2-2 Intentional and Unintentional Radiated Electric Field Emissions Limits at the SMBA Instrument Interface, 18 to 235 GHz (TBR) and values (TBR/TBD/TBS)

ISE

Instrument Provider

PER

17 7.3.2.3 Table 7.3.2-3 SMBA Receive Sensitivity (TBR), values (TBR/TBS), and Notes (TBS)

ISE

Instrument Provider

PER

18 7.3.2.3 Receive Sensitivity (TBR) degrees from the aperture boresight(s)

ISE

PER

19 7.6.3 SMBA-272 outgas at a rate greater than 4.62E-7 gram/second (TBS).

Instrument Provider

PER

Appendix A

Verification Cross Reference Matrix

(VCRM) [TBS]

Instrument Provider

CDR

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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

4 SMBA SCIENCE REQUIREMENTS

4.1 SMBA Channel Requirements

4.2 Radio Frequency Interference Detection Capability

4.3 System Calibration Uncertainty

4.4 Radiometric Sensitivity

4.5 Channel Dynamic Range

4.6 Channel Linearity

4.7 Noise Characteristics

4.8 Beam Characteristics

4.8.1 Beam Polarization

4.8.2 Beam Pointing

4.8.3 Channel Rejection

4.8.4 Gain

4.8.5 Scan Characteristics

4.9 Spectral Response Function

4.10 Calibration

5 NEON SERIES-1 INSTRUMENT 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

5.5.4 Satellite Activation, Checkout, and Commissioning Phase

5.5.5 Mission Operations Phase

5.5.6 End-of-Life Decommissioning Phase

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5.6 Instrument Functional Requirements

5.6.1 Typical Satellite Modes

5.6.1.1 Spacecraft OFF Mode

5.6.1.2 Launch Mode Functional Requirements

5.6.1.3 Spacecraft Safe Modes

5.6.1.4 Spacecraft Engineering Mode

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

5.6.2.5 Instrument Operational Mode

5.6.3 Contingency Management

5.7 Instrument Design Requirements

5.7.1 Mechanical Alignment Requirements

5.7.2 Structural Requirements

5.7.3 Mechanism Design Requirements

5.7.3.1 Torque/Force Margins

5.7.3.2 Binding/Jamming/Seizing

5.7.3.3 Scan Motor

5.7.3.4 Mechanism Performance and Strength Analysis

5.7.4 Electrical Systems Requirements

5.7.5 Electromagnetic Interference and Electromagnetic Compatibility Requirements

5.7.6 Thermal Control Requirements

5.7.7 Instrument Flight Software Requirements

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 (CPT)

7.2.3 Limited Performance Tests (LPT) and Aliveness Tests

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

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

7.3 EMC/EMI Test Requirements

7.3.1 Radiated Emissions (RE)

7.3.1.1 Radiated Emissions, Electric Field, RE102

7.3.1.2 RE, Magnetic Field, RE101

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 Transmitter Frequencies

7.3.2.3 RS, SMBA Instrument Compatibility

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7.3.2.4 RS, Magnetic Field, RS101

7.3.3 Conducted Emissions Tests

7.3.3.1 CE101

7.3.3.2 CMCE

7.3.3.3 CE 102

7.3.4 Conducted Susceptibility Tests

7.3.4.1 CS101

7.3.4.2 CS06

7.3.4.3 CS114CM

7.3.4.4 CS114DM

7.3.4.5 CS115

7.4 Structural and Mechanical Test 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 Test Requirements

7.6 Thermal Vacuum Environmental Test Requirements

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 VERIFICATION CROSS REFERENCE MATRIX (VCRM)

APPENDIX B ACRONYMS/ABBREVIATIONS

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List of Figures

Figure 3.1-1. On-Orbit Coordinate Systems Figure 4.3-1. Notional Calibration Uncertainty Contributions 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 Satellite Mode Transitions Figure 5.6.1-2. Typical Spacecraft Configuration for Earth-Pointing Safe Mode Figure 5.6.1-3. Typical Spacecraft Configuration for Sun-Pointing Safe Mode Figure 5.6.1-4. Typical Spacecraft Configuration for Engineering Mode and Science Operations

Mode Figure 5.6.2-1. Typical Instrument Mode Transition Diagram Figure 7.3.3-1. Common Mode Conducted Emissions (CMCE) Limit Figure 7.3.4-1. Instrument Power Lead Conducted Susceptibility (CS101) Voltage Limit Figure 7.3.4-2. Instrument Power Lead Conducted Susceptibility (CS101) Power Limit Figure 7.3.4-3. Conducted Susceptibility, Power Line Injection (CS114), Calibrated Level and

Current Limit Figure 7.4.2-1. Payload Acoustics Maximum Predicted Environment (MPE) Design Envelope 80 Figure 7.4.3-1. SMBA Acceptance Random Vibration Environment Figure 7.4.3-2. Minimum Workmanship Random Vibration Test Levels Figure 7.4.5-1. Shock Response Spectrum (SRS) for Assessing Component Test Requirements

Figure 7.6.2-1. Qualification, Protoflight, and Flight Acceptance Thermal-Vacuum

Temperatures

List of Tables

Table 2.1-1. Applicable Document List Table 2.2-1. Reference Documents List Table 4.1-1. SMBA Letter Designations for Frequency Bands Table 4.1-2. Hyperspectral and RFI Detection Capabilities by Band Table 4.1-3. NEON Program Microwave Sounder Heritage Channel Requirements Table 4.1-4. NEON Program Microwave Sounder Channel Performance Requirements Table 5.4.2-1. Mission End-to-End Pointing Requirements[1] Table 5.6.1-5. Suggested Instrument Calibration Maneuver Requirements (TBS) Table 5.6.2-1. Instrument Mode Characterization Table 5.6.2-2. Built-in Tests Table 5.7.2-1. Flight Hardware Design/Analysis Factors of Safety Applied to Limit Loads [¹] [²]

Table 5.7.7-1. Flight Processor Resource Utilization Limits Table 6.2-1. Radiated Susceptibility Electric Field Levels Due to Launch Site

(Factory/Transport, PPF, Launch Vehicle, Ascent) and On-Orbit Phases (TBR) Table 6.2-2. Radiated Susceptibility Levels Due to In-Band Sources in On-Orbit Phases

(TBD/TBR/TBS)

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Table 7.3-1. Instrument and Subsystem Level Test Applicability Matrix Table 7.3.1-1. Unintentional Radiated Electric Field Emissions, 14kHz to 18 GHz Table 7.3.2-1. Spacecraft Transmitter Frequency Susceptibility Test Levels (TBD/TBR) Table 7.3.2-2. Intentional and Unintentional Radiated Electric Field Emissions Limits at the

SMBA Instrument Interface, 18 to 235 GHz (TBR) Table 7.3.2-3. SMBA Receive Sensitivity (TBR) Table 7.4-1. Structural and Mechanical Verification Test Requirements Table 7.4.1-1. Test Factors and Durations Table 7.4.2-1. Payload Acoustics MPE Design Envelope Table 7.4.3-1. SMBA Acceptance Random Vibration Environment Table 7.4.3-2. Component Minimum Workmanship Random Vibration Test Levels Table 7.4.4-1. SMBA Acceptance Sine Environment (All Axes)

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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, mission assurance, safety, design, performance, integration, test, and delivery requirements for the instrument provider.

1.2 Document Scope

This specification establishes the requirements for the 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

Over 2016-2018, the National Environmental Satellite, Data, and Information Service (NESDIS) initiated the National Oceanic and Atmospheric Administration (NOAA) Satellite Observing System Architecture (NSOSA) study to determine the most cost-effective space architectures for NOAA’s future weather environmental remote sensing missions. Among the results of the NSOSA study was a confirmation for the continuing and evolving need for global environmental observations from low earth orbit (LEO). In response, NESDIS defined the Near Earth Orbit Network (NEON) program to meet existing and emerging global observational needs from LEO.

Organizationally, the NEON program and its projects reside within the NESDIS Office of LEO Observations and the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) LEO Programs Division (LPD). The NEON Series-1 (NS1) Project is within the NEON Program.

The NS1 Project will field the next generation LEO microwave (MW) sounding observational capabilities that support Department of Commerce (DOC) Primary Mission Essential Functions (PMEF), and NOAA strategic objectives associated with terrestrial weather prediction and warning, healthy oceans, and resilient coastal communities and economies. NS1 is the follow-on microwave instrument continuity mission to the Joint Polar Satellite System (JPSS) Advanced Technology Microwave Sounder (ATMS) observations. Satellite-based Microwave temperature and humidity soundings to be provided by the NS1 satellites are the two largest impact sources of observations for forecasts. NS1 will utilize microwave sounding to provide necessary atmospheric state information for numerical weather prediction and other applications. The National Weather Service’s weather products need three-dimensional atmospheric state information which is provided by atmospheric sounding in the form of vertical profiles (state) of atmospheric water vapor and temperature.

The NS1 Project scope includes satellites that host low Earth orbit (LEO) Earth-observing microwave sounding instruments, related ground services (i.e., command and control, and data routing, processing, distribution, and archival), and launch services. The NS1 mission consists of flight, launch, and ground segments along with the interfaces necessary for the collection of

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environmental data. This includes the periodic data downlink to ground stations and continuous Direct Broadcast (DB) allowing for data product generation and distribution to users. NS1 consists of single instrument satellites operating in a sun synchronous orbit each with a design life of 5-years. It includes development, integration, test, launch, and science operations of the Sounder for Microwave-Based Applications (SMBA) instrument. The SMBA instrument will produce global atmospheric temperature and moisture profiles allowing the NEON Program to provide science continuity with ATMS while introducing the addition of more frequency bands, hyperspectral data collection, and Radio Frequency Interference (RFI) detection capabilities.

NS1 will utilize best practices and processes of the commercial space industry to meet Federal program level requirements while delivering these critical SMBA hyperspectral microwave sounding observation capabilities utilizing small satellites that can be flexibly deployed.

1.4 The Sounder for Microwave-Based Applications

The SMBA instrument is the principal instrument aboard the NEON Series-1 satellites. The instrument (hereafter referred to as the 'SMBA instrument' or simply the 'instrument'), is a cross-track microwave sounder that 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 2,500 km from an altitude of 824 km.

Hyperspectral capability indicates fine spectral resolution, which is beneficial for both science and radio frequency interference (RFI) detection capability. Hyperspectral microwave capability refers to microwave sounding systems with approximately 100 or more channels. The increased number of channels results in a finer spectral resolution than is achieved by traditional microwave sounding techniques over the same bandwidth.

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 the application packets as inputs to the Raw Data Records (RDR). Engineering, instrument telemetry, science, radiometric, and spectral calibration data are also provided to enable the RDRs to be calibrated and geolocated. Together these enable calibration and geolocation. Additionally, diagnostic data may be acquired. The application packets are sent to the National Oceanic and Atmospheric Administration (NOAA) Ground System where they are used to help generate higher level products such as RDRs, Temperature Data Records (TDR), Sensor Data Records (SDR), and Environmental Data Records (EDR).

The instrument system performance requirements are provided in subsequent sections.

1.5 Requirements Definitions

Throughout this PRD:

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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.

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.

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

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

The term “instrument” refers to the SMBA instrument which may be constructed of one or more components that are individually mounted to the spacecraft.

The term “component” is used in various ways throughout this document. For structural requirements, the term component is used to describe the instrument whether it be a singular “component” or a suite of interconnected components that mount to the spacecraft. For all other sections, the term “component” is used more broadly to describe lower level parts or an aggregation of parts into a small functional unit (e.g., parts, sensors, switches, relays, small mechanisms, etc.).

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

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.

The term “spacecraft” may refer to the spacecraft bus.

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) (NS1-SMBA-SOW-0002)”) and satisfy the requirements of this PRD.

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.

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.

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

The term “TBS” (to be supplied) indicates 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 NS1-SMBA-xxx-xxxx

* NEON Series-1 Spacecraft to SMBA Instrument Interface Control Document (TBS)

NS1-SMBA-xxx-xxxx

* NEON Series-1 Spacecraft to SMBA Instrument Mechanical Interface Control Document (TBS)

470-LEO-ANYS-

00018

Rev - 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)

MIL-STD-461G G

December 11, Requirements for the Control of Electromagnetic Interference Characteristics of Subsystems and Equipment

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

Measurement of Electromagnetic Interference Characteristics (Notice 2)

NASA-STD-5001 B w/ change 3 Structural Design and Test Factors of Safety for Spaceflight Hardware

GSFC-STD-7000

Section 2.5.2.1.1 Section 2.5.2.1.2 Section 2.5.2.2.3

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

NASA-STD-8719.14 C NASA Process for Limiting Orbital Debris NASA-STD-8719.24 Rev A, Annex

Rev B with Change 1

NASA Payload Safety Requirements

NPR 8715.6 B NASA Procedural Requirements for Limiting Orbital Debris

*See Contract Attachment N, Applicable Documents List, for 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 ASTM E595 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

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

472-00228 B JPSS Flight Project Contamination Control Plan

JSC-CR-06-070 August

Space Vehicle RF Environments

NASA-STD-5017 B Mechanism Design Requirements http://outgassing.nasa.gov Outgassing Data for Selecting

Spacecraft Materials https://www.bipm.org/en/committees/jc/j cgm/publications

Joint Committee for Guides in Metrology. (2012). International vocabulary of metrology: Basic and general concepts and associated terms (VIM) (3rd ed., JCGM 200:2012). Bureau International des Poids et Mesures.

http://www.itl.nist.gov/div898/handbook/ NIST/SEMATECH e-Handbook of Statistical Methods

E. Kim et al., "An Evaluation of NOAA- 20 ATMS Instrument Pre-Launch and On-Orbit Performance Characterization"

E. Kim et al., "An Evaluation of NOAA-20 ATMS Instrument Pre- Launch and On-Orbit Performance Characterization," in IEEE Transactions on Geoscience and Remote Sensing, vol. 60, pp. 1-13, 2022, Art no. 5302813, doi:

10.1109/TGRS.2022.3148663.

D0001-M01-S01-

001_JPSS_ATBD_ATMS_SDR_B

Version 1 NOAA ATMS SDR ATBD https://www.star.nesdis.noaa.gov/jpss /ATMS.php

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3 GENERAL REQUIREMENTS

3.1 On-Orbit Coordinate System

The 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.

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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).

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4 SMBA SCIENCE REQUIREMENTS

In Section 4, all requirements apply over the life of the instrument.

4.1 SMBA Channel Requirements

A frequency band is a portion of the electromagnetic spectrum associated with a letter designation. For typical use in SMBA, refer to the frequencies and associated letter designation in Table 4.1-1.

Table 4.1-1. SMBA Letter Designations for Frequency Bands

Letter Designation Frequency Range Band Purpose K band 20 - 25 GHz Column Integrated Observations & Quality

Control Ka band 31 - 33 GHz Window V band 50 - 62 GHz Temperature (T) W band 85 - 92 GHz Window F band 108 - 123 GHz Temperature (T) D band 164 - 167 GHz Window G band 173 - 193 GHz Humidity (q) J band 200 - 238 GHz Window & Ice Cloud Detection

The SMBA instrument design may cover a subset of the frequency range associated with a letter designation. The frequency range is not prescribing precise start and stop frequencies or bandwidths. The instrument frequency plan should take into consideration required heritage channels, additional hyperspectral channels, science benefits, RFI detection methods, downlink throughput, hardware constraints, International Telecommunication Union (ITU) allocations, etc.

Science benefits might include, for example, using more hyperspectral bandwidth in a frequency band than utilized by the heritage channels to improve Noise Equivalent Delta Temperature (NEDT) or use more hyperspectral bandwidth to characterize features in the oxygen and water vapor lines.

A channel is the portion of a frequency band defined by a spectral response function (SRF). For the SMBA instrument, SRF is defined as a magnitude of energy versus frequency transfer function, where the input is at the antenna aperture and the output is at the instrument output.

The output of the instrument for a channel corresponds to the integrated energy under the SRF.

A channel is only within one frequency band and does not span across multiple frequency bands.

Center frequency is defined as the median frequency between the half-power points of a passband.

Bandwidth is defined as the spectral width of a passband, where the width is the frequency range between the half power points that define the start and stop frequencies. The total bandwidth of a channel is the sum of the bandwidths of the passbands comprising the channel.

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Center frequency stability is defined as the maximum deviation from the center frequency over the operational life of the instrument.

Hyperspectral capability indicates a fine spectral resolution of the electromagnetic spectrum within a given specified frequency band. Fine spectral resolution enabled by a hyperspectral capability will be beneficial to address science needs and RFI detection needs (Section 4.2).

While hyperspectral capabilities will allow finer spectral resolution, the instrument need not downlink all of the collected bandwidth. The downlinked channels should be a balance between data volumes and spectral resolution.

SMBA-2 Hyperspectral capability shall be provided for the frequency bands identified in Table 4.1-2.

Table 4.1-2. Hyperspectral and RFI Detection Capabilities by Band

Frequency Bands

Hyperspectral Capability

RFI

Detection Capability

Hyperspectral Resolution (MHz)[4]

K Required[1] Required ≤ 10.0 Ka Required[1] Required ≤ 10.0 V Required[2] Required ≤1.0 for spectrum within 30 MHz of the absorption peaks at 56.9682 GHz and 57.6125 GHz, with the objective to extend this capability to additional absorption peaks as design permits.

≤ 10.0 elsewhere W Required[1] Required ≤ 20.0 F Required[2] Not

Required ≤ 20.0

D Not Required Not Required

N/A

G Required[3] Not Required

≤ 100.0

J Not Required Not Required

N/A

Notes:

[1] Capability required for Window Channels continuously in operational mode.

[2] 20 or more channels required in V band and 10 or more channels in F Band for Temperature Sounding continuously in operational mode.

[3] 10 or more channels required in G Band for Moisture Sounding continuously in operational mode.

[4] Hyperspectral Resolution also applies to RFI detection spectral resolution.

SMBA-3 For science continuity, the SMBA instrument shall provide the heritage channels at the center frequencies, bandwidths, and NEDT as identified in Table 4.1-3 with the channel performance of Table 4.1-4.

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SMBA-4 In addition to the heritage channels, the instrument shall provide new hyperspectral and/or RFI detection channels within the same band that meet the channel performance of Table 4.1-4.

Note: New channels may use or reuse any frequency spectrum within the same band. New channels may be formed by aggregating the minimum hyperspectral resolutions. Aggregated channel bandwidths do not need to be uniform across the frequency band.

Table 4.1-3. NEON Program Microwave Sounder Heritage Channel Requirements

Center Frequency[1] (GHz)

Bandwidth (GHz) +/- 5%

NEDT[2]

(K)

23.8 0.27 0.30

31.4 0.18 0.35

50.3 0.18 0.40

52.8 0.4 0.27 53.166 53.326

0.140 0.140

0.32

53.481 53.711

0.17 0.17

0.29

53.867 54.029

0.142 0.142

0.32

54.4 0.4 0.27

54.94 0.4 0.27

55.5 0.33 0.30

57.290344 0.33 0.34 57.073344 57.507344

0.078 0.078

0.50

56.920144 57.016144 57.564544 57.660544

0.036 0.036 0.036 0.036

0.52

56.946144 56.990144 57.590544 57.634544

0.016 0.016 0.016 0.016

0.78

56.958144 56.978144 57.602544 57.622544

0.008 0.008 0.008 0.008

1.10

56.963644 56.972644 57.608044 57.617044

0.003 0.003 0.003 0.003

1.79

88.2 2.0 0.20

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89 4 0.15

114.75 1.0 0.30

115.95 0.8 0.30

116.65 0.6 0.40

117.25 0.6 0.40

117.80 0.5 0.40

118.24 0.38 0.50

118.58 0.30 0.50

165.5 3.0 0.30 176.31 190.31

2.0 2.0

0.28

178.81 187.81

2.0 2.0

0.28

180.31 186.31

1.0 1.0

0.40

181.51 185.11

1.0 1.0

0.40

182.31 184.31

0.5 0.5

0.57

229 2.0 0.40 Notes:

[1] In the Center Frequency column, each boxed row is one channel and contains one or more passbands. The passbands in each row are the passbands to be aggregated to form the heritage channel. For example, Table 4.1- 3 lists one channel with two passbands centered at 176.31 GHz and 190.31 GHz. Fewer passbands in a channel may be used, provided the Temperature Sensitivity requirements are met for the heritage channel bandwidth.

[2] NEDT values:

(a) Assume a 300K scene temperature observation.

(b) Assume no RFI in measurement.

(c) Apply to the instantaneous field of view (IFOV) as defined in Section 4.4. Instrument provider to show

NEDT computed values from the IFOV.

Note: Calibration accuracy, NEDT, and Thermal Noise Contribution to NEDT requirements are found in Sections 4.3 and 4.4, respectively. The NEDT in Table 4.1-3 includes both thermal noise and 1/f noise contributions and therefore are not to be scaled. The Thermal Noise Contribution to NEDT in Table 4.1-4 is to be scaled for integration time and bandwidth.

SMBA-5 The center frequency stability of the channels shall be less than or equal to the values listed in Table 4.1-4.

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Table 4.1-4. NEON Program Microwave Sounder Channel Performance Requirements

Frequency Bands Center Frequency Stability (MHz)

Total Calibration Accuracy

(absolute value of Eacc) (K)

Thermal Noise Contribution to

NEDT[1]

(K)

K 5 1.0 19.8 Ka 5 1.0 18.9

V for < 56 GHz V for ≥ 56 GHz

0.3 0.3

0.5 0.5

21.6 25.0

W 18 1.0 36.0 F 1 0.5 40.0 D 22 0.5 66.5 G 9 0.5 72.0 J 22 0.5 72.0

Notes:

[1] Thermal Noise Contribution to NEDT values:

(a) Assume a 300K scene temperature observation.

(b) Apply to an integration time of 1 msec and a bandwidth of 1 MHz. To scale the values for the actual integration time and bandwidth, divide the value by square root of (actual integration time in msec*actual bandwidth in MHz).

(c) Assume no RFI in measurement.

(d) Apply to the instantaneous field of view (IFOV) as defined in Section 4.4. Instrument provider to show

NEDT computed values from the IFOV.

SMBA-6 In frequency bands requiring hyperspectral capability, the hyperspectral resolution shall be as specified in Table 4.1-2.

Note: Heritage channels (Table 4.1-3) have bandwidths greater than the minimum hyperspectral resolution (Table 4.1-2) and will be formed by aggregating the minimum hyperspectral resolutions. Aggregated channel bandwidths do not need to be uniform across the frequency band.

SMBA-7 For all hyperspectral and RFI detection bands, the number of channels, number of passbands, center frequency of each passband, bandwidth of each passband, and frequency resolution shall be reprogrammable on orbit.

4.2 Radio Frequency Interference Detection Capability

The global expansion of other ITU services into bands adjacent to and overlapping with SMBA bands poses a threat to the quality of the radiometric data and, therefore, to the accuracy of numerical weather prediction (NWP) forecasts and other products. Accurate RFI detection will allow NWP models and science community users to identify contaminated observations and act accordingly.

Table 4.1-2 requires on-board RFI Detection Capability for frequency bands that might experience RFI. Given the importance of these bands for science performance and continuity, the hyperspectral capability enhances the RFI Detection Capability of the SMBA instrument.

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The on-board RFI Detection Capability should incorporate flexible, repeatable, and effective methods to identify and characterize the continually changing man-made sources of interference over the SMBA mission life.

SMBA-8 Detection of RFI by man-made signals that impact operational data products shall be reported for all spectral bands identified in Table 4.1-2. Note: Man-made signals may be continuous, pulsed, narrowband, broadband, etc.

RFI detection should occur at the appropriate processing level to allow assessment of the RFI detection algorithm and to maximize the preservation of science data.

SMBA-9 The instrument shall be capable of on-board RFI detection simultaneously with science data collection.

SMBA-10 The instrument shall be capable of concurrently executing multiple RFI detection algorithms in operational mode and diagnostic mode.

SMBA-11 In operational and diagnostic modes, the instrument shall be capable of collecting, storing, and relaying to the spacecraft raw data used for RFI detection. Note: Raw data can be used on the ground for assessment of RFI detection algorithms. Raw data refers to internal instrument data along the processing chain prior to the formation of channels. Raw data may include data in time domain and/or frequency domain.

SMBA-12 SMBA RFI detection shall have the capability to enable or disable detection functions through on-board scripts and ground commanding. Note:

Examples of RFI detection functions include selecting frequency bands, selecting geolocations, and selecting type of raw data to downlink.

SMBA-13 When RFI is detected, an RFI detection packet shall be generated.

A SMBA RFI detection packet provides the information to compute metrics on RFI detection algorithm performance. Ground processing will produce science data quality flags and metrics based on the RFI detection packet.

SMBA-14 An RFI detection packet shall identify the algorithm that detected the RFI, threshold exceedance, frequency range corrupted, channel(s) affected, and time stamp. Note: Spacecraft provides time stamp and ephemeris data.

RFI detection is performed by processing the signal mathematically and comparing against a threshold. Given the evolving RFI environment, reprogrammability of the RFI detection capability will allow SMBA to adapt.

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SMBA-15 On orbit, the SMBA instrument shall have the capability to reprogram at a minimum both new RFI detection algorithms and thresholds through ground command.

4.3 System Calibration Uncertainty

The SMBA definitions and requirements associated with calibration uncertainty are intended to be in accordance with the National Institute of Standards and Technology (NIST), Bureau International des Poids et Mesures (BIPM), and E. Kim et al., "An Evaluation of NOAA-20 Advanced Technology Microwave Sounder (ATMS) Instrument Pre-Launch and On-Orbit Performance Characterization." If discrepancies exist among definitions in these documents, the usage in this PRD takes precedence.

Uncertainty is defined as the total uncertainty comprised of the accuracy contributions and the precision contributions, as conceptually shown in Equation 1 below.

Accuracy is defined as the systematic portions of uncertainty that are constant or vary in a predictable manner, also known as bias.