Attachment_B_-_Landsat_9_Ground_System_Operations_Concept_Document_(GSOCD)_1.pdf

LSDS-1633

Version 6.0

Department of the Interior U.S. Geological Survey

Landsat 9 Ground System Operations Concept Document (GSOCD)

February 2022

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Executive Summary

This Landsat 9 Ground System Operations Concept Document (GSOCD) describes the characteristics of the Landsat 9 (L9) Ground System (GS) and describes the functions, operations, and personnel that comprise the ground system.

Landsat represents the world's longest continuously acquired collection of space-based moderate-resolution land remote sensing data. More than four decades of imagery provide a unique resource for those who work in agriculture, geology, forestry, regional planning, education, mapping, and global change research. Landsat images are also invaluable for emergency response and disaster relief.

This document is under the USGS Landsat Ground System (GS) Configuration Control Board (CCB) control. Please submit changes to this document, as well as supportive material justifying the proposed changes, via a Configuration Change Request (CCR) to the Process and Change Management Tool.

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Contents

Executive Summary ...................................................................................................... ii

List of TBDs / TBRs ........................................................... Error! Bookmark not defined.

Document History ............................................................. Error! Bookmark not defined.

Contents ........................................................................................................................ iii

List of Figures .............................................................................................................. vi

List of Tables ................................................................................................................ vi

Section 1 Introduction

1.1 Background

1.2 Mission Objectives

1.3 Purpose and Scope

1.4 Document Organization

1.5 Terminology

1.6 References

1.6.1 Applicable Documents

1.6.2 Reference Documents

Section 2 L9 Overview

2.1 Science Mission Overview

2.2 Space Segment

2.3 Launch Services Segment

2.4 Ground Segment

2.4.1 Ground System

2.4.2 Operations

Section 3 Ground System (GS) Operations

3.1 GNE Operations

3.1.1 GNE

3.1.2 GNE Operators

3.1.3 Activities

3.2 Data Processing and Archive Operations

3.2.1 Data Processing and Archive System (DPAS)

3.2.2 DPAS Operators

3.2.3 Activities

3.2.4 DPAS Imaging Model

3.3 LMOC Operations

3.3.1 Landsat Multi-Satellite Operations Center (LMOC)

3.3.2 LMOC FOT

3.3.3 Activities

3.3.4 Mission Data Management

3.4 GS Reporting

3.5 Ground System (GS) Geographic Description

3.6 GS Backup/Restore & Disaster Recovery

3.7 Science and Calibration Operations

3.7.1 Data Acquisition Manager (DAM)

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3.7.2 Landsat Science Team (LST)

3.7.3 Mission Management Officer (MMO)

3.7.4 Mission Acquisition Analyst (MAA)

3.7.5 Calibration and Validation Team (CVT)

3.7.6 Science Modeling System

3.8 Ground System External Interfaces

3.8.1 L9 Observatory

3.8.2 NASA Space Network (SN)

3.8.3 NASA Near Earth Network (NEN)

3.8.4 NASA Flight Dynamics Facility (FDF)

3.8.5 GSFC Space Asset Protection Mission Support Office

3.8.6 CARA and SpaceNav Conjunction Assessments

3.8.7 NASA Earth Science Mission Operations (ESMO)

3.8.8 NASA Moderate Resolution Imaging Spectrometer (MODIS)

3.8.9 NOAA National Centers for Environmental Prediction (NCEP) North American Regional Reanalysis (NARR)

3.8.10 NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) Modern-Era Retrospective analysis for Research and Applications Version 2 (MERRA-2)

3.8.11 US Naval Observatory (USNO)

3.8.12 Spacecraft and Instrument(s) Vendors

3.8.13 Observatory at Integration and Test Facility

3.8.14 Observatory at Launch Site

3.8.15 International Cooperators (ICs)

3.9 User Community

Section 4 Mission Phases

4.1 Prelaunch

4.1.1 Prelaunch Development and Testing

4.1.2 Ground System (GS) Integration and Test (I&T)

4.2 Launch and Early Orbit (L&EO)

4.2.1 Launch Day

4.2.2 Launch and Ascent

4.2.3 Separation

4.2.4 First Orbit Determination

4.3 Observatory Activation and Commissioning

4.3.1 Spacecraft Activation

4.3.2 Instrument Activation

4.3.3 Initial Acceptance

4.3.4 Underfly

4.3.5 On-Orbit Commissioning

4.3.6 Final Acceptance

4.4 Operations

4.5 Decommissioning

Section 5 Ground System Scenarios

5.1 Observatory Management

5.1.1 Description

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5.1.2 Assumptions

5.1.3 Walkthrough

5.2 Mission Data Management Retransmission

5.2.1 Description

5.2.2 Assumptions

5.2.3 Walkthrough

5.3 Science Data Reception and Assembly

5.3.1 Description

5.3.2 Assumptions

5.3.3 Walkthrough

5.4 Ingest

5.4.1 Ingest and Safeguard

5.4.2 Ingest Error Recovery

5.5 Product Request, Generation and Distribution

5.5.1 User Community Product Request

5.5.2 Off-Nadir/Night Imaging Special Collection Request (SCR)

5.5.3 Calibration and Validation Request

5.6 International Cooperators

5.6.1 Nominal IC Contacts and DV&E

5.7 Observatory Health and Safety

5.7.1 Monitoring Observatory Health and Safety

5.7.2 Orbit Maintenance and Maneuvers

5.8 LMOC Facility Failover

5.8.1 Description

5.8.2 Assumptions

5.8.3 Walkthrough

5.9 Remote Ground Station Outage

5.9.1 Description

5.9.2 Assumptions

5.9.3 Walkthrough

5.10 Spacecraft Anomaly

5.10.1 Description

5.10.2 Assumptions

5.10.3 Walkthrough

Section 6 System Outputs

6.1 Standard Products

6.1.1 Level 0 Reformatted Archive (L0Ra) Data

6.1.2 Level 0 Reformatted Product (L0Rp) Data

6.1.3 Level 1 (L1)

6.1.4 Level 1 Systematic Terrain (Corrected) L1GT

6.1.5 Level 1 Terrain Precision (Corrected) L1TP

6.1.6 Level 2 Surface Reflectance Data Products (L2)

6.1.7 Level 2 Surface Temperature Data Products (L2)

6.2 Calibration

6.2.1 Calibration Parameter File (CPF)

6.2.2 Bias Parameter File (BPF)

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6.2.3 Response Linearization Look Up Table (RLUT)

6.3 Mission Data Files

Appendix A Acronyms

Appendix B Nominal GS Activities

List of Figures

Figure 2-1. L9 Operational Concept Architecture Figure 3-1. L9 GS Physical Locations

Figure 3-2. L9 GS Physical Locations (Continued) Figure 3-3. International Cooperators Figure 4-1. L&EO Phase

Figure 5-1. Scenario Conventions Figure 5-2. Observatory Management Figure 5-3. Mission Data Management Retransmission Figure 5-4. Science Data Reception and Assembly

Figure 5-5 Ingest and Safeguard Figure 5-6. Ingest Error Recovery

Figure 5-7. Product Request, Generation and Distribution Figure 5-8. Off-Nadir/Night Imaging SCR Figure 5-9. Calibration and Validation Request

Figure 5-10. Nominal IC Contact and DV&E Figure 5-11. Observatory Health and Safety

Figure 5-12. Orbit Maintenance and Maneuvers

Figure 5-13. LMOC Facility Failover

Figure 5-14. Ground Station Outage Figure 5-15. Spacecraft Anomaly

Figure B-1. Nominal Ground System Activities

List of Tables

Table 1-1. Applicable Documents Table 1-2. Reference Documents Table 3-1. Calibration and Validation Activities Collection Types

Table 5-1. Observatory Management

Table 5-2. Mission Data Retransmission Table 5-3. Science Data Reception and Assembly Table 5-4. Ingest and Safeguard

Table 5-5. Ingest Error Recovery Table 5-6. Product Request, Generation and Distribution Table 5-7. Off-Nadir/Night Imaging SCR Table 5-8. Calibration and Validation Request Table 5-9. Nominal IC Contact and DV&E Table 5-10. Observatory Health and Safety

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Table 5-11. Orbit Maintenance and Maneuvers

Table 5-12. LMOC Facility Failover

Table 5-13. Ground Station Outage Table 5-14. Spacecraft Anomaly Table 6-1. Quality Band Bit Definitions

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Section 1 Introduction

The Landsat 9 (L9) mission is a joint mission formulated, implemented, and operated by the National Aeronautics and Space Administration (NASA) and the Department of the Interior (DOI) U.S. Geological Survey (USGS). L9 is a remote sensing satellite mission providing coverage of the Earth’s land surfaces. This mission continues the 40 plus years of global data collection and distribution provided by the Landsat series of satellites.

1.1 Background

The goal of L9 is to continue the collection, archival, and distribution of multispectral imagery affording global, synoptic, and repetitive coverage of the Earth’s land surfaces at a scale where natural and human-induced changes can be detected, differentiated, characterized, and monitored over time. The L9 goal is consistent with the Landsat programmatic goals stated in the United States Code, Title 15 Chapter 82 “Land Remote Sensing Policy” (derived from the Land Remote Sensing Policy Act of 1992).

This policy requires that the Landsat Program provide data into the future that are sufficiently consistent with previous Landsat data to allow the detection and quantitative characterization of changes in or on the land surface of the globe. The L9 mission is conceived as a follow-on to the highly successful Landsat series of missions that have provided satellite coverage of the Earth’s continental surfaces since 1972. The data from these missions constitute the longest continuous record of Earth’s surface as seen from space.

L9 ensures that Landsat-like data be provided to the USGS National Satellite Land Remote Sensing Data Archive (NSLRSDA) for at least five years. The intent with the implementation of L9 is to leverage, to the extent practical, the designs and systems used for Landsat 8 (L8).

1.2 Mission Objectives

The major mission objectives are as follows:

• Collect and archive medium resolution (circa 30 meter (m) spatial resolution) multispectral image data affording seasonal coverage of the global land mass for a period of no less than five years, with no credible single-point failures.

• Collect and archive medium-low resolution (circa 120 m ground-sample distance) thermal image data affording seasonal coverage of the global land mass for a continuous period of no less than five years, with no credible single-point failures.

• Ensure that L9 data are sufficiently consistent with data from the earlier Landsat missions, in terms of acquisition geometry, calibration, coverage characteristics, spectral characteristics, output product quality, and data availability to permit studies of land cover and land use change over multi-decadal periods.

• Distribute L9 data products to the public on a nondiscriminatory basis.

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1.3 Purpose and Scope

The primary purpose of the L9 Ground System Operations Concept Document (GSOCD) is to describe the functions and operations of the systems, people, and processes that encompass the L9 Ground System (GS) and operations. This GSOCD is not a requirements document and does not contain L9 requirements. Rather, this document presents a functional view of the L9 System and operations based on high-level Landsat Project guidance.

The scope of this document includes all functions associated with the L9 GS, as well as the external entities that interact with the L9 GS. This document encompasses mission planning, Observatory management, and command transmission to the Observatory;

GS reception of Observatory telemetry and image data; data processing and archiving and distribution of data for the Landsat user community.

1.4 Document Organization

This document contains the following sections:

• Section 1 introduces L9 and this document

• Section 2 provides a high-level overview and describes external users and interfaces of the GS

• Section 3 describes the L9 GS operations and their associated activities

• Section 4 describes the operational phases of the mission

• Section 5 illustrates L9 operational scenarios for selected sequences of events during GS operations

• Section 6 provides the L9 GS outputs

• Appendix A provides a list of acronyms

• Appendix B provides a graph of Nominal Ground Station Activities

1.5 Terminology

Long-Term Acquisition Plan (LTAP) – Comprises the input Land Database (LDB), as well as the modeling and planning logic, used to define the LTAP Collection Request (LCR) output file.

* For further information of the science data acquisition strategy for the L9 mission, refer to LSDS-1724 Landsat 9 Long Term Acquisition Plan (LTAP-9)

Collection Request – The Landsat Multi-Satellite Operations Center (LMOC) uses collection requests to schedule acquisitions on the satellite. There are three types of collection requests:

• Long Term Acquisition Plan (LTAP) Collection Requests (LCRs), submitted by the Data Acquisition Manager (DAM)

• Special Collection Requests (SCRs), submitted by authorized users

• Calibration Collection Requests (CalCRs)

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LCRs and SCRs are submitted through the Collection Request Interface (CRI) within the Data Processing and Archive System (DPAS). CalCRs are handled internally by the LMOC. The status of all Collection Requests is sent from the LMOC in the Image Data Status Report (IDSR).

LTAP Collection Request (LCR) – Specific type of collection request, which is the deliverable product of the Long-Term Acquisition Plan (LTAP); this product is a global delineation of all Worldwide Reference System-2 (WRS-2) path/row locations acquired at every overflight, if possible. Each scene defined within the LCR is scheduled for collection within the defined constraints of the system and has an assigned priority to assist in reduced collection capability operations. The LCR is generally static but is configurable, if deemed necessary, to meet operational needs.

Calibration Collection Request (CalCR) – Non-earth imaging calibrations scheduled in coordination with operations and the Calibration and Validation Team (CVT). CalCRs do not include shutter and normal calibrations executed approximately each orbit and are submitted within the LMOC. The collection types that are included in CalCRs are defined in the L9-02-13 Interval Data Collection Concept Document.

Special Collection Request (SCR) – Special Earth collects submitted in reference to the WRS-2 grid that are not in the LCR. SCRs include four categories: off-nadir, Science Campaign (SC), Individual User Request (IUR), and International Cooperators (ICs). SCRs generally represent short-term acquisition interests.

Nadir – Direction when instrument apertures are Earth facing.

1.6 References

1.6.1 Applicable Documents

The documents in Table 1-1 are considered to form a part of this document.

Document Number Version / Release Date Document Title

L9-02-02 Rev A / April 2018 Mission Operations Concept Document

L9-02-01 Rev B / May 2018 Landsat 9 Science and Mission Requirements Document

LSDS-1724 3.0 / August 2020 Landsat 9 Long Term Acquisition Plan

(LTAP-9)

Table 1-1. Applicable Documents

1.6.2 Reference Documents

The documents in Table 1-2 provide additional background and context for this document.

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Document Number

Version / Release Date Document Title

LSDS-551 Version 8.0 / November 2020 Land Satellites Data System (LSDS) International Ground Station (IGS) Data Validation and Exchange (DV&E) and Certification Plan

LSDS-1634 Version 11.0/ February 2021 Landsat 9 (L9) Ground System Requirements Document (GSRD)

LSDS-1659 Version 7.0 / February 2021 Landsat 9 (L9) Ground System Interface Requirements Document (GSIRD)

LSDS-1728 Version 2.0 / September 2018 Landsat 9 Ground System Data Volume Analysis

L9-04-02 Rev A / October 2016 Government Calibration and Validation Plan

LMO-MPS-PLN-0001 Version (5) / Release Date (TBD) Landsat Mission Operations (LMO) Activity and Collection Definition Concept

453-NENUG Rev. 1 Near Earth Network User’s Guide

450-SNUG Rev. 9 Space Network User’s Guide

Table 1-2. Reference Documents

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Section 2 L9 Overview

The L9 system includes all components and capabilities under the developmental and operational responsibilities of the Interagency L9 team. They are both space- and ground-based. The L9 system entails three major mission components: Space Segment, Launch Services Segment, and Ground Segment. The Space Segment includes the spacecraft bus, the Operational Land Imager 2 (OLI-2) instrument, and the Thermal Infrared Sensor 2 (TIRS-2) instrument. The Launch Services Segment is comprised of the Launch Vehicle (LV), launch site, and launch preparation facilities. The Ground Segment is made up of the Ground System and Operations. Figure 2-1 depicts the L9 Ground System operational concept architecture.

Figure 2-1. L9 Operational Concept Architecture

2.1 Science Mission Overview

The primary science objective of the L9 mission is to generate a global high-quality observational record of land image data in continuity with the Landsat satellite series.

LSDS-1724 Landsat 9 Long Term Acquisition Plan (LTAP-9) describes how L9 collects science data. The basic premise of the LSDS-1724 is to acquire all defined, sunlit,

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collection sites as defined in the Long Term Acquisition Plan (LTAP) Collection Request (LCR) that includes a table of path/row-based information, and includes all land, coastal / littoral regions, islands, reefs, atolls, and shallow water ecosystems where the sensors provide useful measurements. In addition, a variety of acquisitions (such as night scenes, off-nadir scenes, science campaigns, etc.) are incorporated through the Special Collection Request (SCR) process and calibration acquisitions (such as solar, lunar, side slither, etc.) are incorporated through the Calibration Collection Requests (CalCRs) process. Due to the distribution of candidate scenes and the annual change in solar illumination, portions of time exist where the candidates may exceed the system capacity. LSDS-1724 addresses methods to select how candidate scenes are rejected when optimizing the schedule to meet resource constraints.

All interfaces related to image scheduling use the Worldwide Reference System-2 (WRS-2) path/row coordinate system convention, including target path/row or orbital path/row and roll angle for off-nadir, even when the Observatory orbit is not compliant with the system. This includes the imaging intervals collected by the instruments, with each scene or imaging sensor activity within the interval being assigned a unique identifier (e.g., path, row, and date). The unique identifiers are shared within the system so that every individual scene requested can be tracked throughout the entire planning, collection and production process.

Calibration and validation of the OLI-2 and TIRS-2 instruments are a key component of proper operations. Operational calibration sequences (shutter, lamp, blackbody, and deep space) and key calibration events (lunar and solar) offer a known source for calibration and on-orbit absolute radiance. These calibration data collections are performed at various frequencies to support the instrument calibration needs.

Periodically, OLI-2 shutter and TIRS-2 deep space collects are acquired and used to determine bias values to apply to the imagery. A variety of other calibration types (lamp, integration time sweeps, etc.) occur less frequently and are used to validate the calibration of the instruments. The lunar calibration is nominally performed once every 28 days and solar calibration is performed approximately once per week (seven to nine days) for radiometric and geometric calibration of the instruments.

An L9 scene size is 185 kilometer (km) cross-track by 180 km along-track, and includes a five percent overlap of the preceding and subsequent scenes. L9 is available to collect at least 838 WRS-2 scenes per 24-hour period, over a 16-day repeat cycle. Instrument Field of Views (IFOVs) are sufficient to cover the 185 km cross-track area of a scene when in the nominal mission orbit and the Observatory is pointing the instruments at nadir. Image data are collected on the spacecraft’s Solid State Recorder (SSR) and transmitted to the Landsat Ground Networks (LGNs) in real-time, playback, or both.

Image data are then transferred via a high-speed Wide Area Network (WAN) to the USGS Earth Resources Observation and Science (EROS) Center for ingest, processing, archive, and distribution.

Off-nadir scene SCRs are made on a scene (or set of scenes) up to one WRS-2 path to the east or west of a possible near-term nadir path. To image scenes along one of these paths, the Observatory must perform up to a + 15 degree roll offset from nadir to align

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the boresights of the instruments along the targeted path. Once the offset is achieved, the instruments begin capturing the off-nadir image data. At the completion of the off-nadir imaging, the Observatory resumes on-nadir imaging. This capability potentially allows a single scene to be imaged up to three times during the 16-day ground track repeat cycle.

All viable image data are processed to the full extent possible. This results in Level 1 (L1) data products that are made available via the web for the science and user community. These data products are available for search and distribution within 24 hours of observations for 85 percent of the data received by the Ground System. Refer to the scenarios in Section 5 for all image data processing activities beginning with the mission data processing through producing the Level 1 image data products.

Furthermore, reference Section 6.1 for the standard products descriptions.

2.2 Space Segment

The Space Segment includes the L9 Observatory and associated Ground Support Equipment (GSE). The GSE provides the functionality to perform ground-based integration and testing of the Observatory before launch. The Observatory consists of the spacecraft and imaging sensors. Northrop Grumman Space Systems in Gilbert, Arizona, provides the spacecraft and Observatory integration support. The onboard sensors include the OLI-2 from Ball Aerospace, and the TIRS-2 provided by NASA Goddard Space Flight Center (GSFC) in Greenbelt, Maryland.

The L9 Observatory operates in a 705 + 1 km sun-synchronous orbit with a 16-day ground track repeat cycle and a 10:00 a.m. (+ 15 minutes) Mean Local Time (MLT) equatorial crossing of the descending node. This allows imaging sensor data to be referenced to the WRS-2 as part of ground processing. In addition, considering that the orbital altitude is the same for L9 and L8, the L9 orbit is phased with respect to L8 orbit such that together they achieve a better repeat cycle for the science mission objectives.

Mission data, which consist of image data and ancillary data, are collected and downlinked to the LGNs via the X-Band communications link. Mission data are always stored for subsequent playback, and mission data acquired during LGN contacts are transmitted to ground in real-time. This link, using separate Virtual Channels (VCs), includes stored housekeeping telemetry data, real-time, and playback mission data to LGNs. Similarly, real-time only mission data are downlinked to International Cooperators (ICs) equipped to receive L9 data. The L9 Observatory also receives and executes commands and transmits real-time and stored housekeeping telemetry to Ground Stations within Ground Network Element (GNE), NASA Space Network (SN), and NASA Near Earth Network (NEN) via the S-Band link.

2.3 Launch Services Segment

The Launch Services Segment provides the assets and services associated with the LV and the Observatory-to-LV integration. Included with the LV is all LV GSE, property, and facilities to integrate the Observatory to the LV, verify their integration, and conduct

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prelaunch testing with ground-based functions. The launch site is located at Vandenberg Space Force Base (VSFB) in California.

2.4 Ground Segment

The L9 Ground Segment comprises the Ground System, Operations, and NASA elements.

2.4.1 Ground System

The Ground System is composed of the GNE, Data Processing and Archive System (DPAS), and Landsat Multi-Satellite Operations Center (LMOC).

2.4.1.1 Ground Network Element (GNE)

The GNE includes the LGN and Data Collection and Routing System (DCRS). The objective of the GNE is to provide highly reliable S-Band and X-Band communication services with the Observatory and route the data appropriately within the Ground System.

2.4.1.2 Data Processing and Archive System (DPAS)

The DPAS ingests and processes mission data to product interval files and subset interval files, and generates Level 0, Level 1 and Level 2 (L2) products for distribution to the public. The DPAS also contains functionality used for the calibration and validation of Landsat data and data products.

2.4.1.3 Landsat Multi-Satellite Operations Center (LMOC)

The LMOC includes all of the ground-based assets needed to operate the L9 Observatory, excluding the ground network. The LMOC plans and schedules all flight operations resources and spacecraft contact activities and supports prelaunch readiness, launch, commission, and operations. The LMOC monitors and controls the L9 Observatory and provides a full suite of attitude and orbit determination capabilities within flight dynamics. The LMOC handles all of the science, calibration, and Observatory activity planning through the generation and verification of stored command loads for the L9 Observatory. Data exchanged with LMOC includes telemetry, command and control, collection requests, plans and schedules, trending and analysis summaries, logs, and additional associated interaction. L9 also includes a fully capable Backup Multi-Satellite Operations Center (bLMOC), which is physically separate from and synchronized with the primary LMOC. The bLMOC is in development and is planned to be available in the event that the primary LMOC experiences a critical failure after L9 is operational.

2.4.2 Operations

The Operations component of the Ground Segment includes ground network operations, data operations, and flight operations.

Ground network operations include the daily operations of the Ground Stations to ensure successful contact with the Observatory. The ground network operations consist of the personnel required to operate and maintain the LGN stations and equipment.

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Data operations include the daily production and distribution of Landsat data products.

This consists of ingesting, processing, monitoring, characterizing, calibrating, validating, collecting metrics, preserving data, etc., thus enabling the detection and quantitative characterization of changes in the Earth’s land surface.

The Flight Operations Team (FOT) is the organization responsible for conducting daily Landsat operations. The main duties include: orbit maintenance and monitoring, conducting mission planning activities, monitoring real-time telemetry, and uplinking daily command products. These duties are conducted using the LMOC systems and tools.

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Section 3 Ground System (GS) Operations

3.1 GNE Operations

3.1.1 GNE

The primary functions of the GNE are as follows:

• S-Band and X-Band Radio Frequency (RF) communications between the Observatory and the ground

• Command and Telemetry (C&T) routing

• Mission data routing

3.1.1.1 RF Communications

The GNE communicates with the Observatory via the LGN. The LGN is comprised of the following ground stations:

• USGS Landsat Ground Station (LGS) at the USGS EROS Center in Sioux Falls, South Dakota

• National Oceanic and Atmospheric Administration (NOAA) Gilmore Creek Station (GLC) in Fairbanks, Alaska

• Kongsberg Satellite Services (KSAT) SvalSat facility (SGS) in Svalbard, Norway

• Geoscience Australia Facility (ASN) in Alice Springs, Australia

• Neustrelitz Ground Station (NSN) in Neustrelitz, Germany

These LGN stations have the capability of simultaneously transmitting the S-Band command uplink to the Observatory while receiving S-Band and X-Band signals. They also support legacy Landsat missions by providing S-band uplink, S-band downlink, and X-band downlink capabilities.

At launch, an excess amount of contact time is scheduled across available stations to ensure ample margin for commissioning; after on-orbit acceptance and over time, the contacts scheduled are trimmed to optimize costs and mission performance.

3.1.1.2 Command and Telemetry Routing

The GNE provides the S-Band Command (CMD) Uplink (U/L) and Telemetry (TLM) Downlink (D/L) along with the network routing of this data between the LGNs and the LMOC in a secure manner. The LGN stations cache S-Band data received for seven days.

3.1.1.3 Mission Data Routing

The GNE provides the X-Band D/L of mission data. The X-Band communications interface includes both the mission data and stored housekeeping telemetry data from the Observatory SSR in addition to real-time X-Band mission data from OLI-2 and TIRS-

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2 instruments. LGN stations cache X-Band data received for 90 days to support continuity of operations, contingencies, and retransfers of data.

The X-Band mission data are routed via a Wide Area Network (WAN) transfer from LGN stations to the EROS facility where assembly of mission data files into complete imaging intervals is performed by the GNE’s Data Collection and Routing System (DCRS). The X-Band mission data are then routed via the EROS Local Area Network (LAN) to the DPAS for archive and processing.

3.1.2 GNE Operators

The GNE Operators oversee the day-to-day LGN station operations. The GNE Operators consist of the local staff at each Ground Station within GNE. The station staff monitors operations, configures automation procedures, and intervenes when problems occur. Some stations are fully automated with staff supporting remotely. The nature of these tasks varies at each Ground Station.

LGS Operators are comprised of the following designations:

• LGN Station Operators

• DCRS Operators

DCRS operations at remote LGN stations are mostly unattended except for the event that there are issues. Therefore, remote LGN Operators are comprised of the following designations:

• LGN Station Operators

3.1.3 Activities

The LGN stations support contacts with the Observatory as scheduled by the LMOC and defined by the station locations and Observatory orbit. Each contact consists of X- Band and S-Band, or X-Band only, or S-Band only; the LMOC determines station resources needed for the contact. X-Band downlink is for image data and stored housekeeping telemetry; an S-Band telemetry downlink is for real-time and stored telemetry; an S-Band command uplink is for real-time and stored commanding.

The GNE systems route mission data files from the Ground Stations to a central GNE cache located at the USGS EROS Center. The GNE systems then verify and assemble the mission data files into complete intervals that the LMOC defines. The mission data interval is then provided to DPAS for archival and product processing. After successful transfer, the interval remains in a rolling cache for a period of time.

The GNE Operators perform multiple activities during a pass event. These activities occur in the following three phases: pre-pass, pass, and post-pass operations. The pre-pass operations verify that the resources are scheduled and properly configured for the pass. The pass operations include communicating with the LMOC, and monitoring the housekeeping telemetry and mission data. The post-pass operations include setting the

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equipment to the configuration prior to pre-pass, and verifying that the GNE Post-Pass Reports (GPR) are sent.

The GNE Operators at the LGS station also interact with the local DCRS, which sends data to DPAS. If required, the GNE Operators monitor logs, research anomalies, and manage the GNE cache.

3.2 Data Processing and Archive Operations

3.2.1 Data Processing and Archive System (DPAS)

Primary DPAS functionality consists of the following:

• Ingest

• Image Processing and Product Generation

• Access and Distribution for users

• Storage and Archive

• Metrics Collection and Reporting

3.2.1.1 Ingest

The objective of the Ingest function is to receive mission data from the GNE for Image Processing, perform initial quality checks (e.g., Cyclic Redundancy Check (CRC), line and frame headers) of mission data intervals, flag suspect timestamps in ancillary data, and generate metadata.

3.2.1.2 Image Processing and Product Generation

The objective of the Image Processing and Product Generation function is to generate standard Level 1 data products, Full Resolution Browse (FRB), and 8-bit Quality Band (QB) for distribution to the public. Characterization data are gathered during processing for the trending, analysis, modeling, calibration, and offline assessment of image quality. The analysis of the characterization data is also used to generate calibration parameters necessary for image processing.

3.2.1.3 Access and Distribution

The Access and Distribution function provides multiple access points to the user community, Calibration and Validation (Cal/Val) Analysts, and support staff. By providing a variety of access mechanisms, both internal and external data consumers have efficient means to discover Landsat data, obtain information, metadata and browse, request and receive products, and submit feedback. Operations are accomplished by six components: Project Website, Data Access Tool (DAT) (EarthExplorer (EE)), Order (Tracking, Routing, and Metrics (TRAM) system), Registration, User Portal (UP) Services, and International Cooperators (ICs) exchange and validation cache (Exchange Cache).

3.2.1.4 Storage and Archive

The objective of the Storage and Archive function is to provide a shared storage for product distribution and DPAS use as well as providing an archive capability for long-

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term preservation of Landsat data. This is accomplished via an Online Cache and an Internal Cache in addition to a long-term archive of data collected to facilitate recovery from operational data loss.

3.2.1.5 Metrics Collection and Reporting

Metrics and collections from DPAS and GNE are collected so that standard and ad-hoc queries and reports can be generated in support of mission management. The Mission Management Office (MMO) is the primary user of the data.

3.2.2 DPAS Operators

The DPAS operational personnel oversee the day-to-day DPAS operations by monitoring the system and performing intervention when necessary.

DPAS Operators comprise the following designations:

• DPAS Console Operators

• Data Quality Analyst (DQA)

• User Services

The DPAS operational personnel provide oversight, quality assurance, distribution, and accounting for the processing of mission data to products. An Operator performs the following key tasks:

• Starting, stopping, and tuning the system component

• Monitoring status indicators for anomalous data and system behavior

• Alerting key mission personnel when an anomaly occurs

• Supporting product media reading / writing operations

• Receiving / disseminating media for IC exchange

3.2.2.1 DPAS Console Operators

DPAS Console Operators oversee the day-to-day DPAS operations by starting, stopping, and tuning the system component. They monitor status indicators for anomalous data and system behavior and alert key mission personnel when an anomaly occurs. DPAS Console Operators support product media reading and writing operations while receiving/disseminating media for IC exchange. DPAS Console Operators initiate reprocessing of Level 0 products, and investigate and resolve processing errors and anomalies. Furthermore, they perform data management and exchange data with the offsite archive and perform Data Validation and Exchange (DV&E) with IC partners.

3.2.2.2 Data Quality Analyst (DQA)

The DQA is a Point of Contact (POC) internal to DPAS who interacts with ICs for DV&E operations. The DQA coordinates and facilitates the data validation process and operational exchange of data to and from IC stations.

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3.2.2.3 User Services

The User Services area provides satellite data product customer services. The User Services personnel provide technical data assistance, respond to inquiries, research issues, track customer feedback and complaints, support business partners, communicate the impacts of upcoming product and processing changes to the user community, and assist project engineers and software engineers with new product options and processes.

3.2.3 Activities

The DPAS is semi-automated and staffed 10 hours a day, 6 days a week.

Examples of automated DPAS operations include the following:

• Ingesting mission data and processing to Level 0

• Generating Level 0 Reformatted Product (L0Rp), Level 1 products, and Level 2 products

• Archiving mission data

• Generating browse data and populating the inventory

• Generating select interval gain and bias parameters during processing

• Providing search and order interfaces online

• Providing online data distribution

• Providing online data acquisition request functionality for authorized users

• Registering users

• Providing product characterization and calibration

Examples of manual DPAS operations include the following:

• Initiating reprocessing of Level 0

• Investigating and resolving errors and anomalies

• Performing data management functions

• Exchanging data with the offsite archive

• Performing data validation and exchange with IC partners

• Assigning user roles

3.2.4 DPAS Imaging Model

The DPAS Imaging Model was developed during the Landsat Data Continuity Mission (LDCM) and is available for use to simulate image data flow latency and end-user impact through DPAS. The DPAS Imaging Model allows configuration of several input parameters for overall analysis. Most important, it examines these high-level functions of DPAS:

• Mission data file ingest

• Level 0 processing/storage

• Level 1 processing/storage

• User data availability/download

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The DPAS Imaging Model primarily exists to study data collection processing and optimization during the prelaunch development and testing phase of the L9 mission.

3.3 LMOC Operations

3.3.1 Landsat Multi-Satellite Operations Center (LMOC)

The primary functions of the LMOC consist of the following:

• Telemetry, Command, and Control

• Flight Dynamics (FD)

• Mission Planning and Scheduling

• Trending and Analysis

• Health and Status Monitoring

• Simulators

A key component to the LMOC functions is the communications infrastructure provided by the Communication Services Office (CSO). The CSO provides WAN, data, voice, fax, video, and other communications services. L9 uses a combination of services of the CSOs mission network services (closed, restricted, and open segments) between the LMOC and other L9 system interfaces. For example, a closed Internet Protocol (IP) Operational Network (IONet) service is used for LMOC telemetry and command data communications with LGN, SN, and NEN stations. In addition, the LMOC and other L9 systems interfaces use the CSO’s dedicated mission voice services, fax, and video services.

3.3.1.1 Telemetry, Command and Control

The LMOC provides the primary means to control and monitor the spacecraft. The interface with the Observatory for Telemetry, Command, and Control is accomplished via front-end processing systems. This allows the LMOC to support unattended operations for limited periods, such as evenings and weekends. Unattended operations include autonomous contacts with Ground Stations, real-time monitoring of the housekeeping telemetry data, monitoring of imaging sensor data receipt acknowledgements, and performing overall Mission Data Management (MDM). The LMOC is capable of autonomously monitoring and reporting systems status.

3.3.1.2 Flight Dynamics (FD)

Many daily activities are performed as part of the FD functions including orbit determination, attitude determination, predictive planning product generation, Onboard Computing (OBC) real-time monitoring, and processing off-nadir requests. These functions are described in the following sections.

3.3.1.2.1 Orbit Determination

Following the receipt of the daily Global Positioning System (GPS) telemetry file, the FD function performs orbit determination and generates the definitive Two-Line Element (TLE). It is also compared: predicted-to-definitive and definitive-to-definitive.

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3.3.1.2.2 Attitude Determination

Following receipt of the daily attitude telemetry file, the FD function performs attitude determination and generates the definitive attitude history file, which is then compared to the previous day’s definitive attitude.

3.3.1.2.3 Predictive Planning Products Generation

Upon receipt of new definitive TLE, the FD function generates the predicted TLE (including maneuver modeling) and compares it to the previous day’s predictive. It executes the slew planning utility to generate slew profiles including generating the predictive attitude history file, generating the slew event file and slew data file (if needed), and checking constraints. It generates planning/TLE generation. It performs attitude prediction and produces multiple planning products.

3.3.1.2.4 OBC Real-Time monitoring

The FD function performs OBC real-time monitoring by comparing the OBC orbit and attitude to the latest predicted.

3.3.1.2.5 Off-Nadir Requests Processing

Upon receipt of an image data collection file and as needed, the FD function processes off-nadir requests by executing the slew planning utility to generate slew profiles including generating the predictive attitude, generating the slew event file and slew data file (if needed), and checking constraints. It re-generates attitude-dependent predicted planning products.

3.3.1.3 Mission Planning and Scheduling

The Mission Planning and Scheduling function is responsible for planning/coordinating and scheduling Observatory and Ground Station activities. It handles generating and maintaining the Master Schedule of activities, including planned and past events from input requests for the life of the mission.

The nominal schedule of activities performed covers a 96-hour period and is generated three times a week at a minimum. Additional schedules can be created leading to command loads uploaded to the spacecraft to account for collision avoidance maneuvers, or to update imaging activities in response to natural disasters.

All interfaces related to image scheduling use the WRS-2 path/row coordinate system convention, even when the Observatory orbit is not compliant with the system. This includes the imaging intervals to be collected by the instruments, with each scene or imaging sensor activity within the interval being assigned a unique identifier (e.g., path, row, and date). The unique identifiers are shared within the system so that every individual scene requested can be tracked throughout the entire planning, collection and production process.

The LMOC generates CalCRs in coordination with the Cal/Val Team. The LMOC uses the current LCR, SCR, and CalCRs, along with orbit information to determine which scenes are to be imaged and when. Consecutive scenes are combined into a single

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imaging interval. Non-consecutive scenes that are close together are treated as a single imaging interval if the time between the end of one and the start of the next is less than the time it takes to stop and re-start recording operations on the Observatory.

For LGN contacts, the real-time X-band downlink is enabled during imaging operations along with the X-band playback downlink. The LMOC determines if a planned interval starts and finishes within the LGN contact and therefore is downlinked on the X-band real-time stream. When the LMOC determines this action occurs, it puts commands within the stored command load to mark the interval/files as being real-time downlinked onboard the Observatory. This method ensures the Observatory does not automatically attempt to playback downlink the interval file on subsequent LGN contacts.

The LMOC schedules activities into the stored command that are within the defined constraints of the system. For imaging of the LCR, the LMOC will schedule only scenes that have a sun angle that exceeds a defined threshold, which the DAM adjusts at their discretion.

3.3.1.3.1 Analytical Modeling

Analytical modeling ensures mission operations occur as expected given any mission system configuration and response to external inputs. Particular configurations are quantitatively modeled with the use of the Joint Activity Simulation for Observatory and Network (JASON) model. The JASON model is an operational tool developed for LDCM and updated for the L9 mission that analyzes mission data and telemetry flow throughout the Observatory and GS with high technical accuracy.

In mission system contingency situations, the Mission Management Officer (MMO) or Flight Systems Manager (FSM) requests usage of the JASON model with situation-based inputs to determine resulting mission system impacts. For example, the FSM may request impact analysis of an observatory that has limited capacity for mission data storage, or adjust which GNE stations are used, and how often. The Flight Operations Team (FOT) uses the JASON model to optimize the mission system configuration based on received guidance.

The FOT uses the JASON model to evaluate significant changes to the LCR, SCR, and CalCRs as part of the CCB process; evaluations span a 16-day cycle or other time period based on operational need. The FOT uses the JASON model to adjust controllable parameters, such as Observatory mass storage utilization and GNE utilization to accommodate requested image data acquisition prior to alerting the DAM of any conflicts.

When mission planning and scheduling system configurations change, the FOT employs the JASON model to ensure that LMOC system outputs and products (e.g., schedules) do not have unexpected results on mission operations; the FOT may configure the JASON model differently across multiple simulations to help troubleshoot systems under test.

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The FOT uses the JASON model when evaluating operating concept changes that involve the Observatory and LMOC. Potential uses include changes to the mission data management approach and exploration of alternative timing of housekeeping activities to determine impacts to science operations or flight operations (e.g., latency of back orbit telemetry).

Given that the bulk of Landsat data acquisition is over sun-lit areas, and that the distribution of targets around the Earth is not uniform, there can be considerable changes in the overall volume, and relative orbit timing of science acquisition throughout the year. Primarily for this reason, some uses of the JASON model include evaluation of up to an entire year of operations.

The JASON model accepts LMOC-external inputs in native format to allow for product format validation within the tool and consistency with the DPAS-LMOC interface specification. LMOC-internal inputs are FOT-controlled and describe operations concepts and mission system configurations. Input configurations include: LCR; CalCR;

SCR; relevant instrument activities; relevant Observatory activities; mission data management; mission planning rules and approaches; and relevant parameters, constraints, and representations of the LMOC, GNE stations, Observatory, and FOT.

The JASON model represents detailed characteristics of mission resources necessary to create outputs in plots displaying values at each discrete time step. The fidelity of the discrete time step is sufficient to evaluate the impacts of how individual station contacts occur, including resultant Observatory mass storage impacts. Output reports include:

data loss and constraint violations; data volume over time; data latency; graphical representations of the time period assessed; Observatory and ground activities executed; input settings; GNE station contact utilization; and Observatory onboard storage utilization.

The JASON model represents specific time periods based on user inputs but generates outputs at a rate significantly higher than real time. For example, the MMO needs results spanning up to a 16-day cycle in minutes, not hours, during contingency situations in order to make timely decisions. For long-term impact assessment, the JASON model runs complete within a few hours. In addition, because the JASON model provides the technical analytic basis for operational decisions, it measures key aspects of mission operations such as Observatory onboard storage utilization, data latency, data volume and GNE station contact utilization with greater than 90 percent accuracy when compared to operations.

3.3.1.4 Trending and Analysis

During nominal mission operations, Observatory housekeeping data received are used to generate trend reports for FOT review. If investigative trending is required, users can generate their own trend reports from the available LMOC trending tools.

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3.3.1.5 Health and Status Monitoring

Routine operations consist of health and status monitoring. FOT performs health and status monitoring to monitor limit violations. Various components of the Observatory are monitored and characterized to ensure a successful mission.

3.3.1.6 Simulators

3.3.1.6.1 Landsat Scalable Integrated Multi-Mission Simulation System

(LSIMSS)

The Landsat Scalable Integrated Multi-Mission Simulation System (LSIMSS) / Command and Telemetry Processor (CTP) is a GNE subsystem comprising a modular, programmable baseband processor. It is used to perform both Consultative Committee for Space Data Systems (CCSDS) Telemetry and Command (T&C) processing and to run a moderate fidelity spacecraft simulator to support prelaunch mission testing and mission operations of the Landsat Project.

The specific functionality is defined by the configuration of modules used in a programmable preset called a “desktop”. When used for LGN T&C processing, the unit is referred to as a “CTP”, and when used to run the spacecraft simulator, it is referred to as an “LSIMSS”.

When used as an LSIMSS, it simulates a subset of the spacecraft Command and Data Handling (C&DH) functions including command validation, stored command processing, and telemetry formatting. LSIMSS can also simulate a large subset of functionality and interfaces of S-Band operations with the LGN, NEN, and SN. It generates the basic S- Band spacecraft telemetry data formats, including housekeeping diagnostic, and playback data formats.

When used as a CTP, it can combine two telemetry streams (according to real-time priority) into one socket stream and forward it to the LMOC. CTP also forwards commands received from the LMOC via socket connection.

3.3.1.6.2 Spacecraft/Observatory Simulator (S/OS)

The S/OS is a spacecraft high-fidelity simulation system, which with the…