NS1-SMBA-REQ-0001B_NS1 SMBA PRD_04172025.pdf

Effective Date: April 17, 2025 Expiration Date: April 17, 2030

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NS1-SMBA-REQ-0001, Revision B Near Earth Orbit Network (NEON) Series-1 Project, Code 473

Near Earth Orbit Network (NEON) 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:

Lisa McCormick ATMS Instrument Systems Engineer LEO Programs Division NASA Goddard Space Flight Center Code 473

Approved by:

Jessica Knizhnik SMBA Instrument Manager LEO Programs Division NASA Goddard Space Flight Center Code 473

Roger Clason Deputy Program Manager NEON Program NASA Goddard Space Flight Center Code 470

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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.

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Table of Deviations/Waivers

Item No. Deviation/Waiver Waiver Approved Effectivity 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.

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

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)

3 4.1 Table 4.1-2 Note [6] Minimum resolution for RFI detection needs (TBR)

ISE

4 4.2 SMBA-14 RFI severity levels (TBD)

5 4.3 SMBA-18 The calibration accuracy uncertainty of the channels (TBS) K.

6 4.7 SMBA-33 The striping index 1.1 (TBR) for all heritage channels and 1.2 (TBR) for all non-heritage channels.

7 4.7 SMBA-34 The inter-channel noise correlation coefficient 0.15 (TBR) for all channels.

8 4.8.4 SMBA-46 The total scan period shall be TBS seconds ±TBS msec.

9 4.9 SMBA-50 SRF magnitude (gain) knowledge (TBD)

ISE

10 4.9 SMBA-51 SRF frequency knowledge

(TBD)

ISE

11 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).

12 5.1 SMBA-105 Uncompensated momentum contribution of ±0.3 N-m-sec per axis

(TBR).

13 5.4

The initial data rate allocations of the instrument shall not exceed 2 Mbps orbital average and not exceed 10 Mbps peak 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.

14 5.4.2 Table 5.4.2-1 Mission End-to-End Pointing Requirements: Pointing Accuracy (TBR), Pointing Knowledge (TBR)

15 5.6.1 Table 5.6.1-5 Suggested Instrument Calibration Maneuver Requirements (TBS) and SMBA-126

16 5.6.1.3.1 Figure 5.6.1-2 Typical Spacecraft Configuration for Earth-Pointing Safe Mode (TBR)

5.6.1.4

Figure 5.6.1-4 Typical Spacecraft Configuration for Engineering Mode and Science Operations Mode (TBR)

18 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.

19 5.7.2 SMBA-153 Worst case expected launch load of 15 g independently in each axis

20 5.7.3.3.1

SMBA-171 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)

21 6.2

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

(TBR)

22 6.2 Table 6.2-2 Radiated Susceptibility Levels Due to In-Band Sources in On-Orbit Phases (TBR/TBS) and values (TBS)

ISE

23 7.3 Table 7.3-1 Instrument and Subsystem Level Test Applicability Matrix (TBR)

24 7.3.1

Table 7.3.1-3 Intentional and Unintentional Radiated Electric Field Emissions Limits at the SMBA Instrument Interface, 18 to 235 GHz (TBR) and values

(TBR)

25 7.3.1 Table 7.3.1-4 SMBA Receive Sensitivity (TBR), values (TBR), and Notes (TBS)

ISE

26 7.3.1.4 Receive Sensitivity (TBD) degrees from the aperture boresight(s)

ISE

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27 7.3.1.4 Table 7.3.1-4 SMBA Receive Sensitivity (TBR) and values (TBR/TBD)

ISE

28 7.3.2 Table 7.3.2-1 Spacecraft Transmitter Frequency Susceptibility Test Levels (TBS/TBR) and values (TBS/TBR)

ISE

29 7.3.2.1 SMBA-232 For the Satellite RS103 Test (on-orbit configuration), the levels in Table 6.2-1 (TBD) (Columns 3 and 4)

ISE

30 7.3.2.1 SMBA-234 For the Satellite RS103 Test (Launch Configuration), the limits in Table 6.2-1 (TBD) (Columns 1 and 2)

ISE

31 7.3.3.2 Figure 7.3.3-1 Common Mode Conducted Emissions (CMCE) Limit [TBS]

32 7.6.3 SMBA-299 outgas at a rate greater than 4.62E-7 gram/second (TBS).

33 Appendix A Verification Cross Reference Matrix

(VCRM) [TBS]

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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

3.3 Risk Classification and Mission Assurance Requirements

4 SMBA SCIENCE REQUIREMENTS

4.1 SMBA Channel Requirements

4.2 Radio Frequency Interference Detection Capability

4.3 Calibration Accuracy

4.4 Temperature Sensitivity

4.5 Channel Dynamic Range

4.6 Channel Linearity

4.7 Noise Characteristics

4.8 Beam Characteristics

4.8.1 Beam Pointing

4.8.2 Channel Rejection

4.8.3 Gain

4.8.4 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 (EMI) and Electromagnetic Compatibility (EMC)

Requirements

5.7.6 Thermal Control Requirements

5.7.7 Contamination Control Requirements

5.7.8 Instrument Flight Software Requirements

5.7.9 Instrument Simulator and Emulator 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 (CPTs)

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 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 RE, Magnetic Field, RE101

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7.3.1.4 RE, 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 Transmitter Frequencies

7.3.2.3 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

7.3.4.6 CS116

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 VERIFICATION CROSS REFERENCE MATRIX (VCRM)

APPENDIX B ACRONYMS/ABBREVIATIONS

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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 4.3-1. Notional Calibration Accuracy 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 [TBS] 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 75 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 4.3-1. Antenna Brightness Temperature Uncertainty Maximum 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 5.7.8-1. 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 (TBR) xiv 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 6.2-2. Radiated Susceptibility Levels Due to In-Band Sources in On-Orbit Phases

(TBR/TBS)

Table 7.3-1. Instrument and Subsystem Level Test Applicability Matrix (TBR) Table 7.3.1-1. Unintentional Radiated Electric Field Emissions (General), 14kHz to 18 GHz, Standard MIL-STD-461G Bandwidths Table 7.3.1-2. Unintentional Radiated Electric Field Emissions, Receiver Frequencies, Narrowband MIL-STD-461G Scans (Modified Bandwidths) Table 7.3.1-3. Intentional and Unintentional Radiated Electric Field Emissions Limits at the

SMBA Instrument Interface, 18 to 235 GHz (TBR) Table 7.3.1-4. SMBA Receive Sensitivity (TBR) Table 7.3.2-1. Spacecraft Transmitter Frequency Susceptibility Test Levels (TBS/TBR) Table 7.4-1. Structural and Mechanical Verification Test Requirements 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, 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

The Near Earth Orbit Network (NEON) Program, in the National Environmental Satellite, Data, and Information Service (NESDIS) Office of Low Earth Orbit (LEO) Observations provides a framework to provide global measurements of Earth systems. These environmental observations will be able to support a wide variety of atmospheric, terrestrial, marine, and polar applications.

The environmental observation data is required by the numerical weather prediction (NWP) models, fire and flood models, atmospheric chemistry observations, and multiple land imagery products that have been a crucial piece of the National Oceanic and Atmospheric Administration (NOAA) strategic goal to create a "Weather 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 the National Aeronautics and Space Administration (NASA).

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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 which are on each of the Joint Polar Satellite System (JPSS) satellites. SMBA will allow the NEON Program to provide continuity with the existing JPSS-era microwave sounder measurements to enable advances through the incorporation 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 Local Time Ascending Node (LTAN)), at any desired launch cadence as the program needs to support hyperspectral microwave sounder needs.

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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 NASA Procedural Requirement (NPR) 8705.4, which applies the appropriate NASA management controls, systems engineering processes, mission assurance requirements and risk management processes. Select areas of redundancy should be considered that offer reasonable improvement to mission success.

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'), 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 Raw Data Records (RDR) in an uncalibrated form. Engineering, instrument telemetry, science, radiometric, and spectral calibration data are provided to enable the RDRs to be calibrated and geolocated. Additionally, diagnostic RDR data may be acquired.

The data are sent to the NOAA Ground System where they are used as input to science algorithms that generate 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:

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.

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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.

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.

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

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) 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-REQ-

A NEON SMBA Instrument Mission Assurance Requirements

NS1-SMBA-xxx-xxxx

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

NS1-SMBA-xxx-xxxx

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

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), Revision C (August 4, 1986)

MIL-STD-461G G

December 11, 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-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 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 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

472-00228 B JPSS Flight Project Contamination Control Plan

JSC-CR-06-070 August 2006 Space Vehicle RF Environments NASA-STD-5017 B Mechanism Design Requirements NPR 8705.4 4/29/2021 Risk Classification for NASA Payloads NASA-STD-8719.24 Initial with

Change 1, Annex with Change 2 Jun 2012

NASA ELV Payload Safety Requirements http://outgassing.nasa.gov Outgassing Data for Selecting Spacecraft Materials

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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).

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 (NS1-SMBA-REQ-0002).

Safety design requirements and requirements for the control of catastrophic and critical failures are contained in SMBA Instrument Mission Assurance Requirements (NS1-SMBA-REQ-0002).

The instrument and its ground support equipment used at the launch site will comply with the NASA-STD-8719.24 NASA Expendable Launch Vehicle (ELV) Payload Safety Requirements or other applicable range safety documentation contained in SMBA Instrument Mission Assurance Requirements (NS1-SMBA-REQ-0002).

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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 - 235 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 science benefits, RFI detection methods, downlink throughput, hardware constraints, etc.

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.

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

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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-3 Hyperspectral capability shall be provided for the frequency bands identified in

Table 4.1-2.

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

Frequency Bands

Hyperspectral Capability

RFI Detection Capability

Hyperspectral Resolution (MHz)

K Required[1] Required[5] ≤ 10[6] Ka Required[1] Required[5] ≤ 10[6] V Required[2] Required[5] ≤1 between 56-58 GHz

≤ 10 outside of 56-58 GHz[6]

W Required[1] Required[5] ≤ 20[6] F Required[2] Not Required ≤ 20 D Not Required Not Required N/A G Required[3] Not Required ≤ 100 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 for continuously in operational mode.

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

[4] Band Frequency Start and Stop to reflect the specifics of the instrument chosen.

[5] RFI detection capability required continuously in operational mode.

[6] Minimum resolution for RFI detection needs (TBR)

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

SMBA-5 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 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)

23.8 0.27

31.4 0.18

50.3 0.18

51.76 0.4

52.8 0.4 53.71080 54.48080

0.17 0.17

54.4 0.4

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54.94 0.4

55.5 0.33

57.290344 0.33 57.073340 57.507340

0.078 0.078

56.920144 57.016144 57.564544 57.660544

0.036 0.036 0.036 0.036

56.946144 56.990144 57.590544 57.634544

0.016 0.016 0.016 0.016

56.958144 56.978144 57.602544 57.622544

0.008 0.008 0.008 0.008

56.963644 56.972644 57.608044 57.617044

0.003 0.003 0.003 0.003

88.2 2.0

114.50 1.0

115.95 0.8

116.65 0.6

117.25 0.6

117.80 0.5

118.24 0.38

118.58 0.30

165.5 3.0 176.31 190.31

2.0 2.0

178.81 187.81

2.0 2.0

180.31 186.31

1.0 1.0

181.51 185.11

1.0 1.0

182.31 184.31

0.5 0.5

229 2.0 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.

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SMBA-6 The center frequency stability of the channels shall be less than or equal to the values listed in Table 4.1-4.

Note: Calibration accuracy and NEDT requirements are found in Sections 4.3 and 4.4, respectively.

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

Frequency Bands[1] Center Frequency Stability (MHz)

Calibration Accuracy

(K)

NEDT[2],[3]

(K*sqrt(msec*MHz))

K 5 0.5 16.7 Ka 5 0.5 15.9 V 0.3 0.5 18.7 W 18 0.5 37.9 F 1 0.5 31.0 D 22 0.4 61.0 G 9 0.4 67.0 J 22 0.5 68.3

Notes:

[1] Provider may utilize any portion(s) of the band and optimize the configuration to enhance hyperspectral capability and RFI detection capability in Section 4.2.

[2] NEDT values assume:

(a) 300K scene temperature observation

(b) an integration time of 1 msec and a bandwidth of 1 MHz

(c) No radio frequency interference in measurement

(d) To scale NEDT for the actual integration time and bandwidth, divide the value by sqrt(actual integration time in msec*actual bandwidth in MHz).

[3] NEDT compliance at raw footprint level is preferred. Instrument provider to show both NEDT computed values from raw footprints and NEDT computed values after resampling or averaging.

SMBA-7 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-8 The configuration of heritage, new hyperspectral, and RFI detection channels identified in SMBA-5 shall be reprogrammable on orbit.

4.2 Radio Frequency Interference Detection Capability

The global expansion of other International Telecommunication Union (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 NWP forecasts and other products. Accurate RFI detection

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(flagging) 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.

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-9 Detection of Radio Frequency Interference (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 flag should occur at the appropriate processing level to allow assessment of the RFI detection algorithm and to maximize the preservation of science data.

SMBA-10 The instrument shall be capable of on-board RFI detection simultaneously with science data collection.

SMBA-11 The instrument shall be capable of executing multiple RFI detection algorithms simultaneously.

SMBA-12 To assess RFI detection algorithms, the instrument shall be capable of collecting, storing, and relaying to ground raw data used for RFI detection.

Note: 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-13 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-14 SMBA RFI detection flag packet shall identify the algorithm, frequency range corrupted, channel(s) affected, and RFI severity level. Note: spacecraft provides time stamp and ephemeris data. RFI severity levels are TBD.

SMBA-15 SMBA instrument shall have the capability to reprogram on-board RFI detection algorithms through ground command.

SMBA-16 SMBA RFI detection capability shall report metrics on RFI detection algorithm performance (i.e., detection sensitivity, false alarms, flagging, diagnostic data, raw data, etc.).

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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 an external calibration reference.

The calibration accuracy is characterized via two parameters: magnitude and uncertainty. The calibration accuracy magnitude describes the size and direction of the difference between the inferred brightness temperature and the actual brightness temperature.

The calibration accuracy uncertainty describes the tolerances associated with the magnitude value. Calibration accuracy magnitude and uncertainty contributions may be acquired on the ground and/or on orbit.

Calibration accuracy contributions include, but are not limited to, brightness temperature of calibration references and the radiometric calibration transfer function (counts to kelvins).

Figure 4.3-1 shows notional calibration accuracy contributions as a reference to be considered for SMBA.

Contributions can include, but are not limited to, uncertainties due to (1) errors contained in the ground calibration tests and the test equipment, (2) the transition from the ground cold calibration reference to the on-orbit cold calibration reference, and (3) emissions from the spacecraft intercepted by the near fields of the radiometer antenna(s).

Figure 4.3-1. Notional Calibration Accuracy Contributions

Notes:

[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.

[2] Traditional radiometers have used two-point calibration methodology: cold space for the cold reference temperature and an on-board blackbody for the warm reference temperature. The instrument design is not constrained to this methodology or these calibration reference types. Other types of calibration references exist such as noise diodes and cold Field Effect Transistors (FET).

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[3] Proposed references that are also standards (as defined by the National Institute of Standards and Technology (NIST)) must include a description of the traceability plan that enables them to be a standard, along with an estimate of the (absolute) accuracy. SMBA follows the NIST definitions of "standard," "reference," "intercalibration," and "intercomparison."

Values for contributions in Figure 4.3-1 are characterized on the ground, on-orbit, and by analysis. Some contributions shown in Figure 4.3-1 have specific requirements associated with them because they may be a relatively large error source, can be best characterized on the ground, impact numerous samples within a scan, and/or are corrected for in the operational algorithm.

A specific calibration accuracy contribution may have dynamic and/or static characteristics.

Dynamic characteristics are those that vary with time. Static characteristics are those that do not vary with time.

This results in a system-level calibration accuracy consisting of dynamic and static contributions.

The time scale of one orbit captures orbital variations. Calibration accuracy is the average error over a time scale longer than one orbit.

Corrections to the data are based on the instrument design are becoming increasingly important as demands for accuracy increase. The instrument provider should have a sufficient understanding of how to make the corrections for the calibration accuracy magnitude and determine the residual uncertainty (error). Static contributions may be corrected for as a bias correction in the algorithm.

SMBA-17 The calibration accuracy magnitude of the channels shall be less than or equal to the values listed in Table 4.1-4.

SMBA-18 The calibration accuracy uncertainty of the channels shall be less than or equal

TBS K.

SMBA-19 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.

SMBA-20 All calibration accuracy computations shall be for 1-sigma statistics properties.

SMBA-21 The brightness temperature uncertainty of the warm calibration target shall be less than or equal to +/-0.20 K.

SMBA-22 The emissivity of any on-board blackbody calibration references shall be greater than or equal to 0.99990 within an uncertainty less than or equal to +/- 0.00003.

SMBA-23 The physical temperature gradient of any warm load calibration reference shall be less than or equal to 0.2 K.

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SMBA-24 The physical temperature uncertainty of any on-board blackbody calibration references shall be less than or equal to +/- 0.1 K.

SMBA-25 The brightness temperature uncertainty of the cold space calibration reference shall be less than or equal to +/- 0.5 K.

SMBA-26 The near-field antenna characteristics shall be determined to sufficient accuracy such that brightness temperature contributions from spacecraft and instrument radiation have an uncertainty less than or equal to the values specified in Table 4.3-1.

SMBA-27 The far-field antenna characteristics shall be determined to sufficient accuracy to ensure that the brightness temperature contributions from Earth radiation have an uncertainty less than or equal to the values specified in Table 4.3-1.

Table 4.3-1. Antenna Brightness Temperature Uncertainty Maximum

Frequency Band Near-field[1],[2] (K)

Far-field[1],[3] (K)

K +/- 0.075 K +/- 0.35 K Ka +/- 0.075 K +/- 0.35 K V +/- 0.05 K +/- 0.20 K W +/- 0.05 K +/- 0.20 K G +/- 0.05 K +/- 0.20 K J +/- 0.05 K +/- 0.20 K

Notes:

[1] Distance, d, is the aperture size of the antenna and λ is the wavelength measured by the antenna.

[2] Distances less than 2d2/ λ from the antenna are defined as near-field.

[3] Distances greater than or equal than 2d2/ λ from the antenna are defined as far-field.

4.4 Temperature Sensitivity

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

Integration time is defined as the time interval over which the radiometric signal is collected for a given channel.

SMBA-28 The temperature sensitivity of the channels shall be less than or equal to the values listed in Table 4.1-4.

SMBA-29 The brightness temperature measurement of an Earth scene or calibration reference shall be independent of any previous measurements.

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4.5 Channel Dynamic Range

SMBA-30 The dynamic range of the instrument shall envelope the brightness temperature range of Earth scenes, calibration references, and be sufficient to meet the RFI requirements in Section 4.2.

4.6 Channel Linearity

Nonlinearity is the departure from the…