Department of the Interior

U.S. Geological Survey

**USGS LDCM**

**Ground Network Element (GNE)**

**Requirements Document**

**Version Draft**

04-29-2008

![](media/image1.png)

EROS

Sioux Falls, South Dakota

[1 Introduction 5](#introduction)

[1.1 Purpose 5](#purpose)

[1.2 Scope 5](#scope)

[1.3 Function 5](#function)

[2 Reference Documents 7](#reference-documents)

[3 Requirements 8](#requirements)

[3.1 General 8](#general)

[3.1.1 GNE Information System Security
8](#gne-information-system-security)

[3.1.2 Institutional 10](#institutional)

[3.2 LGN Station 10](#lgn-station)

[3.2.1 General 10](#general-1)

[3.2.2 Antenna 12](#antenna)

[3.2.3 S-Band Equipment 14](#s-band-equipment)

[3.2.4 X-Band Equipment 17](#x-band-equipment)

[3.2.5 Ground Station Control (GSC) 18](#ground-station-control-gsc)

[3.3 Scheduling and Reporting System (SRS)
20](#scheduling-and-reporting-system-srs)

[3.4 Data Collection and Routing Subsystem (DCRS)
22](#data-collection-and-routing-subsystem-dcrs)

[3.4.1 DCRS General 22](#dcrs-general)

[3.4.2 DCRS File Routing 22](#dcrs-file-routing)

[3.4.3 DCRS Interval Routing 22](#dcrs-interval-routing)

[3.5 Network 24](#network)

[3.5.1 General 24](#general-3)

[3.5.2 Mission Data Return Connection
24](#mission-data-return-connection)

[3.5.3 Telemetry and Command Connection
25](#telemetry-and-command-connection)

[3.5.4 Scheduling and Reporting Connection
25](#scheduling-and-reporting-connection)

[3.6 Interfaces 25](#interfaces)

[3.6.1 External GNE Interfaces 25](#external-gne-interfaces)

[4 Appendix A: Allocations 29](#appendix-a-allocations)

[5 Appendix B: Traceability Matrix 30](#appendix-b-traceability-matrix)

[6 Appendix C: Verification Matrix 33](#appendix-c-verification-matrix)

[7 Appendix D: Priority Matrix 36](#appendix-d-priority-matrix)

[8 Appendix E: Acronyms 39](#appendix-e-acronyms)

# Introduction

## Purpose

## Scope

This document establishes the Requirements for the Ground Network
Element (GNE) broken down into the operational subsystems as described
in the GNE Operational Concepts Document.

## Function

Figure 1-1 illustrates a segment level diagram of the LDCM System. The
GNE is the focus of this document and is circled in red in the diagram.

![](media/image2.png){width="5.967361111111111in" height="4.375in"}

Figure 1-1 LDCM Segment Diagram Focusing on the Ground Network Element

Figure 1-2 Illustrates the element level functional diagram of the GNE.

![](media/image3.jpeg){width="6.490972222222222in"
height="6.195833333333334in"}

Figure 1-2 GNE Functional Architecture

# Reference Documents

Landsat Data Continuity Mission (LDCM) Ground System Requirements
Document

Landsat Data Continuity Mission (LDCM) Ground System Requirements
Document

Mission Operations Element Requirements Document (MOERD)

Landsat Data Continuity Mission (LDCM) Ground System Operations Concept
Document

Ground Network Element (GNE) Operations Concept

Observatory Interface Requirements Document (OIRD)

CCSDS 727.0-B-4 CCSDS File Delivery Protocol Blue Book

# Requirements

## General

**GNE474:** The GNE shall deliver at least 99% of the mission data
acquired by the LGN to the science data archive, measured on a quarterly
basis.

**Rationale:** Supporting the delivery of science data to the archive.
In supporting the parent requirement the GNE has an allocation of 0.6%
which will be broken out in an appendix.

**GNE28:** The GNE shall provide at least 100 minutes per day of X-Band
contact time with the Observatory.

**Rationale:** This contact time is required in order to provide
sufficient contact time to downlink all science data. Derived assuming a
downlink rate of twice the realtime acquisition rate. (400 scenes \*
23.92 s/scene / 2 channels / 60 s/min \* 16 days/cycle \* 1.25) The 125%
factor provides for calibration data and capacity to catchup a backlog
situation.

### GNE Information System Security

**GNE587:** The GNE shall provide network connectivity in compliance
with the LDCM IT security policy.

**Rationale:** The GNE will abide by IT security policy when applicable.
Certain circumstances may exist where waivers may be required (current
Landsat configurations require waivers).

**GNE654:** The GNE shall employ automated mechanisms to support the
management of information system accounts.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53. The requirement would include the deletion of temporary and
emergency accounts along with automated deletion of inactive accounts.

**GNE655:** The GNE shall employ automated account management
notification of information systems.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53. Ensures the GNE employs automated mechanisms to ensure
account creation, modification, disabling, and termination actions are
audited and the appropriate individuals are notified.

**GNE656:** The GNE shall enforce assigned authorizations to control
access to GNE assets.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53. The IS enforces the assigned authorizations for controlling
access to systems in accordance in accordance with applicable policies.

**GNE657:** The GNE shall restrict IS security functions to authorized
users.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53. The IS restricts access to security functions and security
relevant information to explicitly authorized personnel.

**GNE658:** The GNE shall employ information flow enforcement for all
computer systems.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53. The information system enforces assigned authorizations for
controlling the flow of information between interconnected systems in
accordance with local security policies.

**GNE659:** The GNE shall utilize the Least Privilege system for
information security on all computer systems.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53. This IT system enforces the most restrictive set of
rights/privileges/accesses for all users to perform their specific
tasks.

**GNE660:** The GNE shall employ automated monitoring/control of all
remote access IT functions.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53.

**GNE661:** The GNE shall utilize cryptography protection for remote
access sessions.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53. The GNE will utilize cryptography to protect the
confidentiality and integrity of remote access sessions.

**GNE662:** The GNE shall restrict wireless access to all GNE assets.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53. The GNE will establish usage restrictions and implement
guidance for wireless technologies.

**GNE671:** The GNE shall control network communications at the external
boundaries of its information systems.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53. This includes protection from denial of service attacks and
putting publicly accessible systems on separate sub networks. The
boundary protection will use a managed interface.

**GNE673:** The GNE shall deny network traffic by default and allow
network traffic by exception.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53. This also includes the release of connections at the end of
active sessions.

**GNE672:** The GNE shall provide information system transmission
integrity.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53. This requirement means the GNE will employ information
system tools and rules that protect the integrity of outgoing
transmissions and provide confidentiality to the transmitter.

**GNE674:** The GNE shall provide mechanisms to protect the authenticity
of communication sessions.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53. This includes not allowing mobile code and having policies
for public key support. This also would restrict any type of
collaborative computing on the critical networks such as video
conferencing on the telemetry return networks.

**GNE675:** The GNE shall provide mechanisms to centrally manage virus
protection tools.

**Rationale:** This requirement supports the GSRD requirement and the
NIST 800-53. The mechanisms can be policies for the use of virus
protection tools and protection from malicious code. The mechanisms will
also provide for flaw remediating.

### Institutional

**GNE651:** The GNE shall be implemented such that the EROS facility
will be automated for 72 hours at a minimum.

**Rationale:** This supports the parent GSRD requirement for creating
EROS to support the 8x5 shifting approach

**GNE652:** The GNE shall be implemented to support a 10 year mission
life or longer.

**Rationale:** The GS is responsible for supporting the 10 year mission
life of the LDCM mission at a minimum and this is a general GNE
translation.

**GNE293:** The GNE shall provide physical security for USGS assets in
accordance with NIST SP 800-53 and all relevant annexes.

**Rationale:** USGS institutional requirement.

## LGN Station

### General 

**GNE209:** All LGN stations shall have the ability to be scheduled
within 15 minutes if the station will be in view of the S/C in the event
that the FOT declares a S/C Emergency.

**Rationale:** In support of rapid response to spacecraft emergencies.
Fifteen minutes is consistent with SN and GN performance. The
requirement is for space craft emergencies and does not affect the
availability of the station in subsequent requirements. The requirement
is for S-Band receive and commanding services only as typically in a S/C
emergency there is no imaging.

**GNE639:** All LGN stations shall have an availability of at least 97%
(TBR) measured on a monthly basis.

**Rationale:** This equates to a 24 hour outage over a month. There is
sufficient LGN contact time margin to accommodate a 24 hour ground
station outage. With multiple apertures available at the polar station,

24 hours allows time to switch to a backup aperture. This also
contributes to the 99.9% GS availability requirement in the GSRD 165 for
critical command functions.

**GNE44:** All LGN Stations shall receive real-time S-band telemetry
from the Observatory.

**Rationale:** GS662 Support for receiving the S-Band telemetry downlink
from the observatory. The reception and transmission of S-Band data are
requirements to be considered an LGN station.

**GNE210:** All LGN stations shall exchange telemetry and command data
with the Observatory as specified in the Space to Ground ICD (Add
Document Number).

**Rationale:** This interface is required for telemetry, commanding and
science data to flow through GNE. The space to ground ICD shall be
provided by the Bus vendor.

**GNE311:** All LGN Stations shall be configurable in an International
Cooperator (IC) Earth Station mode of operation (TBC).

**Rationale:** The current Landsat 7 LGN includes an IC station
operating in this mode. This requirement will support testing of the IC
functionality of the Bus.

**GNE262:** All LGN Stations shall transmit command uplink data from MOE
to the Observatory in real time.

**Rationale:** The parent requirement in GSRD specifies within 1 second
time which is a cost driver for measurement.

**GNE263:** All LGN Stations shall transmit command uplink data from
bMOE to the Observatory in real time.

**Rationale:** The parent requirement in GSRD specifies within 1 second
time which is a cost driver for measurement.

**GNE94:** All LGN stations shall provide real time S-band telemetry
data to two MOE facilities simultaneously.

**Rationale:** Test requirement and support for IOC operations and MOE
facility change over.

**GNE237:** All LGN stations shall provide S-Band services while
simultaneously retransmitting previously received stored telemetry from
a prior pass to the MOE.

**Rationale:** This interface is required for telemetry, commanding and
science data to flow through GNE.

**GNE235:** All LGN stations shall initiate the retransmission of stored
telemetry data to the MOE within 1 hour of receiving the retransmission
request from the FOT.

**Rationale:** This allows manual retransmission of stored telemetry
data.

**GNE253:** All LGN stations shall accept RF output from the RF suitcase
test equipment.

**Rationale:** The GNE is required to support GRT testing and RF
Compatibility testing prior to launch. In support of the mission level
I&T plan.

**GNE250:** All LGN stations shall generate timestamps with an accuracy
of 100 microsecond or better.

**Rationale:** Clock calibration onboard the observatory is supported
through the accuracy of GNE time tagging of realtime telemetry data.

### Antenna

####  General

**GNE480:** The antenna shall program track the Observatory.

**Rationale:** LGN ground stations must generate pointing angles, the
MOE will not provide these data. Program track is defined as tracking
the observatory utilizing the acquisition data IIRV to build a computed
track path of the observatory. Program tracking does not utilize the
signal from the Observatory for tracking but should allow the reception
and transmission of S-Band successfully while program tracking.

**GNE481:** The antenna shall utilize acquisition data IIRV for
positioning and program tracking.

**Rationale:** Compatibility with present practice and LDCM MOE
operations concept (IIRV). TLE is a contingency-mode format.

**GNE513:** The antenna shall perform configurable automatic signal
tracking (auto-track).

**Rationale:** Without automatic signal tracking the reception of the
X-Band signal would not be efficient.

**GNE482:** The antenna shall autonomously switch between program and
autotrack modes of operation.

**Rationale:** The antenna shall have a preference for autotracking
X-Band signals. The autonomous switch over is required for the antenna
to begin to program track then switch to autotrack when the signal
strength is high enough to provide reliable data reception. The
autonomous switching will be for both directions to and from program
track and autotrack.

**GNE483:** The antenna shall receive X-band data and S-band data
concurrently while sending S-band data.

**Rationale:** Matches the performance specification for the
observatory.

**GNE532:** The antenna shall provide real time status to the GSC.

**Rationale:** In support of GNE operations and maintenance staff
troubleshooting and GNE to MOE interface agreement.

####  X-Band Characteristics

**GNE514:** The antenna shall perform automatic signal tracking using
the X-Band signal.

**Rationale:** The rationale for this link is due to receiving X-Band
data it requires automatic signal tracking to accomplish the task.
Without autotrack X-Band data would not be reliably received.

**GNE493:** The antenna shall be capable of simultaneously receiving two
X-band signals.

**Rationale:** Limited to two carriers to limit ground station expense -
2 carriers is sufficient for all reasonably conceivable communications
architectures. Requirement changed from 3 carriers to two to match bus
vendor RFO

**GNE491:** The antenna shall have an X-band G/T of at least 31 dB/K at
5 degrees elevation clear sky.

**Rationale:** Compatible with heritage 10 m LGN antennas supporting a
reasonable link margin. The requirement does not intend to include any
radome effects. With or without a radome the required specification must
be achieved.

**GNE511:** The antenna shall receive the transmission of X-Band
spectrally overlapping channels separated by polarization (TBD) from the
Observatory.

**Rationale:** Dual-polarization downlinks may be required to achieve
the overall data throughput requirements depending on the modulations
and other design choices made by the bus vendors.

**GNE489:** The antenna shall provide X-Band axial ratio of 1.5 dB (TBD)
or better.

**Rationale:** Required axial ratio supports the required 28 dB of
isolation between the dual polarization. The 1.5 dB requirement is
listed in the Bus IRD. The requirement does not intend to include any
radome effects. With or without a radome the required specification of
1.5 dB axial ratio or better must be achieved.

**GNE512:** The antenna shall support selectable LHC and RHC
polarization on each X-band downlink channel (TBR).

**Rationale:** These represent the only two polarization reasonable for
the LDCM S-band link.

####  S-Band Characteristics

**GNE494:** The antenna shall transmit S-band command uplink to the
Observatory compliant with the space to ground ICD ( add ICD number).

**Rationale:** Compatibility with observatory RD stated capability.

**GNE495:** The antenna shall transmit S-band LHCP or RHCP signals
(TBR).

**Rationale:** This represents the transmit requirement from the GSRD.
Currently the transmit polarization is not known, so making requirement
cover both.

**GNE519:** The antenna shall support the S-Band transmit frequency
range of 2025 MHz to 2108 MHz (TBR).

**Rationale:** This represents the entire spectrum allocation for Earth
Science missions for telemetry uplink.

**GNE520:** The antenna shall support the S-Band receive frequency range
of 2200 MHz to 2290 MHz (TBR).

**Rationale:** This represents the entire spectrum allocation for Earth
Science missions for telemetry downlink.

**GNE496:** The antenna shall have an S-Band uplink with a minimum EIRP
of 54 dBW.

**Rationale:** Compatible with heritage 9 m LGN antennas supporting a
reasonable link margin. The requirement does not intend to include any
radome effects. With or without a radome the required specification must
be achieved.

**GNE497:** The antenna shall have an S-band G/T of at least 20 dB/K at
5 degrees elevation clear sky.

**Rationale:** Compatible with heritage 9 m LGN antennas supporting a
reasonable link margin. The requirement does not intend to include any
radome effects. With or without a radome the required specification must
be achieved.

### S-Band Equipment

**GNE72:** The S-Band equipment shall receive S-Band RF signals from the
antenna.

**Rationale:** Interface requirement so the S-Band equipment interfaces
to the antenna system in case of multiple vendors. Duplicated in
interface section.

**GNE492:** The S-Band equipment shall support selectable BPSK S-band
modulation formats consistent with CCSDS 401.0-B (TBC).

**Rationale:** BPSK modulation is robust, widely adopted and sufficient
for the LDCM S-band requirements.

**GNE73:** The S-Band receive equipment shall receive real time S-Band
telemetry at 2 Kbps, 16 Kbps and 32 Kbps (TBR).

**Rationale:** This maximum rate was chosen as a worst case for what is
required to downlink the stored telemetry data assuming the highest rate
in GS546 was also used as the stored telemetry generation rate.

**GNE641:** The S-Band receive equipment shall receive the S-Band stored
telemetry data at 1 Mbps aggregate (TBR).

**Rationale:** This requirement supports the playback and realtime
aggregate rates from the observatory.

**GNE74:** The S-Band transmit equipment shall support command data
rates of 1 Kbps and 32 Kbps (TBR).

**Rationale:** This range of standard rates goes from the low-rate
tumbling TDRSS case all the way up to a maximum which supports a large
stored command load in a single LGN contact.

**GNE294:** The S-Band transmit equipment shall support a configurable
sweep of the command uplink at a rate of 5 KHz - 35 KHz/second (TBR).

**Rationale:** The uplink sweep supports proper negotiation of the space
to ground communications and is typically considered standard practice
on the Landsat missions.

**GNE75:** The S-Band transmit equipment shall support a configurable
sweep of the command uplink of up to +/- 160 KHz about the center
frequency.

**Rationale:** The uplink sweep supports proper negotiation of the space
to ground communications and is typically considered standard practice
on the Landsat missions.

**GNE76:** The S-Band transmit equipment shall produce a decaying sweep
of the command uplink signal.

**Rationale:** GS662 Support for decaying the uplink to allow the
observatory to synchronize with the ground station prior to turning on
modulation for proper signal acquisition by the observatory. Decaying
sweep is defined as returning the swept uplink carrier signal back to
the center frequency at a controlled rate so the Observatory does not
lose lock on the ground station uplink signal.

**GNE77:** The S-Band transmit equipment shall BPSK modulate the S-Band
command uplink (TBR) complaint with the space to ground ICD (ICD #).

**Rationale:** GSRD GS550 requires BPSK modulation. BPSK modulation is
robust, widely adopted and sufficient for the LDCM S-band requirements.

**GNE78:** The S-Band receive equipment shall BPSK or QPSK (TBR)
demodulate signals from the S-Band received telemetry data carrier
compliant with the Space to Ground ICD.

**Rationale:** BPSK modulation is robust, widely adopted and sufficient
for the LDCM S-band requirements.

**GNE81:** The S-Band receive equipment shall demodulate received S-band
data and modulate S-band uplink data simultaneously.

**Rationale:** GS662 Support for demodulating the S-Band telemetry data
for transfer to the MOE.

**GNE84:** The S-Band receive equipment shall store a minimum of 7 (TBR)
days of telemetry files.

**Rationale:** GS654 Support for playing back historical telemetry files
to the MOE for trending and troubleshooting.

**GNE85:** The S-Band receive equipment shall timestamp all telemetry
data frames with an accuracy of 100 microseconds or better.

**Rationale:** Clock calibration onboard the observatory is supported
through the accuracy of GNE time tagging of realtime telemetry data.

**GNE351:** The S-Band receive equipment will store data time stamped
with a precision of 100 microseconds.

**Rationale:** Timestamp formats must support the accuracy requirement
in GS534.

**GNE86:** The S-Band receive equipment shall store telemetry files with
unique filenames.

**Rationale:** Support S-Band file playback capabilities.

**GNE87:** The S-Band receive equipment shall support CCSDS-131.0-B-1 TM
Synchronization/Channel Coding.

**Rationale:** Support for GS547.

**GNE396:** The S-Band transmit equipment shall support CCSDS 231.0-B-1
command uplink Synchronization/Channel Coding.

**Rationale:** Support for GS548.

**GNE88:** The S-Band transmit equipment shall receive Observatory
command data from the MOE.

**Rationale:** The requirement supports both the encrypted and
non-encrypted command uplink data streams from the MOE.

**GNE91:** The S-Band receive equipment shall transfer stored playback
telemetry files to the MOE.

**Rationale:** GS664 Support for telemetry file playback to the MOE upon
request.

**GNE92:** The S-Band receive equipment shall transfer real time
housekeeping telemetry data to the MOE in real-time.

**Rationale:** GS544 Support for sending telemetry files to the MOE in
real time.

**GNE95:** The S-Band transmit equipment shall be capable of sending the
command uplink to the antenna.

**Rationale:** GS662 Interface support for sending command uplink data
from the S-Band processing equipment to the antenna for transmit to the
observatory.

**GNE561:** The S-Band equipment shall send real time S-Band data
quality statistics to the GSC.

**Rationale:** In support of troubleshooting of GN links by the Flight
Operations Team and GNE operations.

**GNE126:** The S-Band receive equipment shall provide remote status of
operational status (green/yellow/red).

**Rationale:** In support of troubleshooting of GN links by the Flight
Operations Team.

**GNE223:** The S-Band transmit equipment at each LGN station shall
introduce no more than 1 error in (TBD bits) during the handling of
command uplink data.

**Rationale:** Required to maintain the link quality between the
Observatory and the Ground station.

Need a parent in GSRD.

**GNE224:** The S-Band receive equipment at each LGN station shall
introduce no more than 1 error in (TBD bits)during the handling the
S-Band receive telemetry.

**Rationale:** Required to maintain the link quality between the
Observatory and the Ground station.

Need a parent in GSRD.

**GNE398:** The S-Band receive equipment shall support selectable
error-correction decoding on the S-Band telemetry downlink compliant
with CCSDS 131.0-B-1, sections 3.1 and 4.

**Rationale:** Error correction codes from CCSDS 131 were chosen to
ensure integrity of the downlink and because the standard is widely
adopted.

**GNE400:** The S-Band transmit equipment shall support selectable
error-correction encoding on the S-Band command uplink compliant with
CCSDS 231.0-B-1.

**Rationale:** Error correction codes from CCSDS 231 were chosen to
ensure integrity of the uplink and because the standard is widely
adopted.

**GNE401:** The S-Band receive equipment shall support selectable
de-randomization of the S-Band telemetry downlink in accordance with
CCSDS-131.0-B-1.

**Rationale:** Derandomization is required to ensure successful
demodulation and CCSDS standards are widely adopted.

### X-Band Equipment

**GNE106:** The X-Band equipment shall demodulate the QPSK format (TBR)
from the observatory.

**Rationale:** This capability is required in order to support the
entire range of space to ground RF interface options provided to the
RSDO vendors. This requirement is subject to reduction of scope or
removal when the bus vendor is chosen.

**GNE279:** The X-Band equipment shall be able to demodulate two X-band
downlink channels simultaneously.

**Rationale:** In support of the bus RFP stating 2 simultaneous X-Band
downlink channels.

**GNE107:** The X-Band equipment shall support configurable
synchronization/channel decoding, as per CCSDS-131.0-B-1 Blue Book Issue
1, September 2003.

**Rationale:** Error detection and correction is necessary to know when
retransmission of data files is required. The CCSDS RS standard is
widely adopted.

**GNE110:** The X-Band equipment shall support data rates up to 300 Mbps
(TBC) per carrier.

**Rationale:** This rate assumes typical overheads for CCSDS protocols
and no compression.

**GNE336:** The X-Band equipment shall remove all artifacts of the space
to ground transmission such as encoding and randomization.

**Rationale:** GNE will not pull apart or process the files beyond how
they are stored on the recorder.

**GNE114:** The X-Band equipment shall accept the X-Band data stream
which is formatted compliant with the \"Class 1\" specification of CFDP,
given in CCSDS 727.0-B-3 File delivery Protocol Blue Book.

**Rationale:** A non-proprietary standard was chosen based on
availability of COTS receiving hardware/software for LGN and IC
stations. This file-based protocol supports the file-based onboard
storage requirements.

**GNE569:** The X-Band equipment shall send real time X-Band data
quality statistics to the GSC.

**Rationale:** This information is important for MOC troubleshooting of
observatory performance as well as GNE operations and maintenance
troubleshooting.

**GNE239:** The X-Band equipment shall provide real-time CFDP data
quality statistics to the GSC.

**Rationale:** This information is to be used to close the CFDP file
status with MOE to initiate retransmission or deletion of files from the
GNE storage.

**GNE242:** The X-Band equipment shall introduce no more than (TBD bits)
during the receipt of the mission data stream from the Observatory.

**Rationale:** Required to maintain the link quality between the
Observatory and the Ground station.

Need a parent in GSRD. Currently no parent exists in the GSRD but there
will be one added to support this requirement.

**GNE243:** The X-Band equipment shall support selectable Reed-Solomon
error decoding on the X-band downlink compliant with CCSDS 131.0-B-1
(TBC).

**Rationale:** Error detection and correction is necessary to know when
retransmission of data files is required. The CCSDS RS standard is
widely adopted.

**GNE245:** The X-Band equipment shall support selectable
derandomization of the X-band downlink in accordance with
CCSDS-131.0-B-1 (TBC).

**Rationale:** Randomization of the X-band downlink will be necessary to
ensure demodulation performance and the CCSDS standard is widely
adopted.

### Ground Station Control (GSC)

**GNE345:** The GSC shall send real-time X-Band quality statistics to
the SRS.

**Rationale:** This information is important for MOC troubleshooting of
observatory performance as well as GNE operations and maintenance
troubleshooting.

**GNE570:** The GSC shall send X-Band CFDP status message in real-time
to SRS.

**Rationale:** This information is important for MOC troubleshooting of
observatory performance as well as GNE operations and maintenance
troubleshooting.

**GNE571:** The GSC shall send Ground Station Equipment (GSE) status
information to the SRS in real time.

**Rationale:** This information is to be used to close the CFDP file
status with MOE to initiate retransmission or deletion of files.

**GNE548:** The GSC shall receive station specific contact schedules
from the SRS.

**Rationale:** The MOE uses its FD to determine contact schedule and
sends selected set to GNE for confirmation.

**GNE549:** The GSC shall configure the LGN station equipment based on
the contact schedule.

**Rationale:** The MOE uses its FD to determine contact schedule and
sends selected set to GNE for confirmation.

**GNE550:** The GSC shall process the acquisition data (IIRV) sent from
the SRS.

**Rationale:** In preservation of spacecraft physical security. This
applies to LDCM inputs for the LDCM Observatory it does not preclude
multi-mission support. The processing includes integrating into master
IIRV file for distribution to LGN stations. Processing also includes
sending acquisition data to proper equipment like the antenna system as
needed.

**GNE552:** The GSC shall collect pass event statistics from the LGN
station equipment.

**Rationale:** The data will be collected at the SRS and inserted into a
post pass report. Post pass reports will allow troubleshooting and
trending of ground station equipment for problem resolution. The report
is data collected at specific intervals throughout the pass event, to
include both pre and post pass times.

**GNE553:** The GSC shall send real-time S-Band quality statistics to
the SRS.

**Rationale:** In support of GNE operations and maintenance staff
troubleshooting and GNE to MOE interface agreement.

**GNE572:** The GSC shall forward the real time pass event statistics to
the SRS.

**Rationale:** This report is needed for troubleshooting problems and
future trending and analysis.

## Scheduling and Reporting System (SRS)

**GNE346:** The SRS shall provide long-range predictions of planned site
outages of the all the LGNs to the MOE.

**Rationale:** In support of the 28 day forecast schedule on the MOE
side.

**GNE248:** The SRS shall be capable of adding a new LGN station or
removing an existing one for scheduling without recompiling the
application code.

**Rationale:** It is expected that the USGS may alter the LGN during the
mission and this helps reduce costs when doing so.

**GNE379:** The SRS shall notify maintenance personnel of critical
system equipment failure.

**Rationale:** In order to satisfy the availability requirements and 8x5
shift requirements the SRS will need to notify maintenance personnel
while the station is not manned.

**GNE357:** The SRS shall collect real time status from the LGN station
during a pass event.

**Rationale:** Support for troubleshooting and notification of issues to
the MOE/MOC/FOT.

**GNE666:** The SRS shall send the LGN station status to the MOE in real
time.

**Rationale:** This information is important for MOC troubleshooting of
observatory performance as well as GNE operations and maintenance
troubleshooting.

**GNE667:** The SRS shall generate the post pass event report utilizing
the status collected during the pass event.

**Rationale:** The post pass event report will be utilized for
troubleshooting performance issues. It will also be utilized to trend
the station and Observatory performance as needed.

**GNE668:** The SRS shall send the post pass event report to the MOE
within 15 minutes of the end of the pass event.

**Rationale:** The post pass event report will be utilized for
troubleshooting performance issues. It will also be utilized to trend
the station and Observatory performance as needed.

**GNE283:** The SRS shall report any LGN station equipment failure or
error to the local operator.

**Rationale:** Support for troubleshooting and notification of issues to
the MOE/MOC/FOT. The requirement is also tied to availability as
failures would need to be repaired or worked around in under 24 hours to
meet the LGN station availability. Also, the reporting will be done via
the operations GUI or other system notification feature.

**GNE282:** The SRS shall collect any station scheduling conflicts from
the LGN GSC.

**Rationale:** Support for MOE schedule requests. Reporting errors
allows for automatic or manual corrections.

**GNE669:** The SRS shall send any LGN station scheduling conflict
reports to the MOE.

**Rationale:** Support for MOE schedule requests. Reporting errors
allows for automatic or manual corrections.

**GNE177:** The SRS shall receive acquisition data (IIRV) files from the
MOE.

**Rationale:** GNE support for IIRV data distribution. This would cover
the nominal file receive. Contingency modes would have the SRS retrieve
the IIRV files from a predetermined location.

**GNE176:** The SRS shall receive contact schedules from the MOE.

**Rationale:** The nominal reception of the contact schedule from the
MOE. The contingency would have the SRS retrieve the contact schedule
from a predetermined location.

**GNE175:** The SRS shall provide each LGN station with acquisition data
(IIRV) files.

**Rationale:** GNE support for IIRV data distribution. This covers the
SRS to create the IIRV files and send them over the network to the
individual station GSC. This would occur at the same time as the contact
schedule dissemination.

**GNE173:** The SRS shall have the capability to interface with two LGN
stations simultaneously.

**Rationale:** Ability for the MOE to communicate with more than one LGN
station at the same time to support multiple events.

**GNE174:** The SRS shall provide each LGN station with an
individualized contact schedule.

**Rationale:** SRS support to provide contact schedule for LGN stations
based off MOE requests. Deconfliction complete at this stage.

**GNE171:** The SRS shall store all reports for a minimum of 6 months.

**Rationale:** Storage of reports allows for trending and analysis for
several months after a potential problem occurred.

**GNE170:** The SRS shall allow the scheduler to manually generate or
update the pass event forecast schedule.

**Rationale:** Supports the long range planning for the MOE scheduling
activities.

**GNE169:** The SRS shall allow the scheduler to manually create a LGN
station specific contact schedule.

**Rationale:** Supports scheduling from MOE in contingency situations
where contact schedule from MOE is not available. This also includes
editing the existing schedule based on contingency mode requirements.

**GNE167:** The SRS shall allow the scheduler to configure the LGN
station equipment configurations.

**Rationale:** Allows operations to configure mission priorities for
contingency and normal operation changes. LGN station configurations
will be pre-built configurations considered nominal equipment. This
requirement allows the scheduler to change the potential equipment or
equipment configuration based on the SRS to GSC functionality.

**GNE372:** The SRS shall maintain a master contact schedule for all LGN
stations.

**Rationale:** Allows the SRS to deconflict pass events based on MOE
requests.

**GNE164:** The SRS shall perform pass deconfliction for all LGN
stations based on a configurable priority scheme.

**Rationale:** Allows the control of resources based on several mission
parameters to utilize the LGN assets for the best possible efficiency.

## Data Collection and Routing Subsystem (DCRS)

### DCRS General 

**GNE428:** The DCRS shall be able to dynamically add one or more ground
stations as an LGN station.

**Rationale:** This needs to be dynamic so that if an LGN station goes
down another station can be added quickly enough so that there won\'t be
loss of mission data. The current Landsat 7 LGN includes an IC station
operating in this mode.

**GNE581:** The DCRS shall operate in either File Routing or Interval
Routing mode of operation.

**Rationale:** This is needed when a catastrophe/contingency calls for
the remote LGN stations to directly pass the mission data to the DPAS.

**GNE576:** The DCRS shall identify new files that are sent to the
cache.

**Rationale:** Move to Level 5

### DCRS File Routing 

**GNE473:** The DCRS shall provide a cache for storing 90 days of
mission data files at each LGN station.

**Rationale:** Supports retransmission to DPAS when required. Ninety
days is consistent with DPAS recovery requirements. Each LGN station
shall store 90 days of mission data files and the DCRS Interval Routing
system will store 90 days of mission data files from all LGN stations.

### DCRS Interval Routing 

**GNE162:** The DCRS shall ingest mission data files from any IC that
are in accordance with the DFCB (TBD).

**Rationale:** In support of station validation and IC data validation
and evaluation activities.

**GNE477:** The DCRS shall notify the IPE Ingest Subsystem (IS) after an
interval has been transferred to SAE.

**Rationale:** Nominal interval transfer and hand shake.

**GNE557:** The DCRS shall provide the mission data directory to the MOE
on configurable intervals.

**Rationale:** The successful ingest of all the mission data file that
make an interval need to be communicated to the MOE so that MOE can
command the observatory SSR to mark these files for deletion.

**GNE146:** The DCRS shall make a CONUS priority interval available to
the IPE IS within 2 hours of LGN capture.

**Rationale:** Supports the data transfer latency requirement to DPAS.

**GNE642:** The DCRS shall make a non-CONUS priority interval available
to the IPE IS within 8 hours of LGN capture.

**Rationale:** Supports the parent latency requirement

**GNE643:** The DCRS shall make all global standard intervals available
to the IPE IS within 16 hours of LGN capture.

**Rationale:** Supports the parent latency requirements.

**GNE129:** The DCRS shall only transfer mission data files to the SAE
that constitute a complete interval.

**Rationale:** In support of data transfer to DPAS. Interval list will
be defined/redefined by MOE in case of a permanent loss of file.

**GNE147:** The DCRS shall flag all files that are successfully ingested
by the IPE IS.

**Rationale:** This will enable the DCRS to delete after 90 days the
successfully ingested files/intervals by the DPAS. This flag occurs
internal to the DCRS and its software and/or database components. The
IPE would return a message to the DCRS upon successful ingestion of the
interval.

**GNE150:** The DCRS shall receive the interval to file mapping table
from the MOE.

**Rationale:** Mapping list is required for transfer of complete
interval support to the DPAS. The nominal state is a push from MOE and
contingency would include a retrieve component.

**GNE151:** The DCRS operator shall initiate ingest of the interval to
file mapping tables as required.

**Rationale:** Mapping list is required for transfer of complete
interval support to the DPAS. This would be a contingency after the
retrieval of the mapping tables.

**GNE278:** The DCRS shall receive mission data interval retransfer
requests from the IPE.

**Rationale:** Retransfer capability allowing the IPE to request
interval retransfer.

**GNE196:** The DCRS shall retransfer mission data intervals to the SAE.

**Rationale:** Retransfer capability in case of contingency. Possible
versioning of the intervals.

**GNE559:** The DCRS shall notify the IPE IS that an interval has been
retransferred to SAE.

**Rationale:** Retransfer capability for notification support.
Versioning will be part of the message for data delivery to the IPE IS.

## Network

### General

**GNE591:** The GNE shall provide network connectivity between the DCRS
and the Infrastructure Element (IE).

**Rationale:** In support of mandatory mission management office data
requirement. The IE will utilize a service oriented architecture SOA for
message and service transfer between all elements. The system needs to
be compliant with the IE SOA to allow communication to the other
elements to properly perform the mission.

**GNE589:** The GNE shall provide network connections to the NISN in
compliance with the NISN security policy.

**Rationale:** In support of testing as well contingency operations.

**GNE425:** The GNE networks shall operate autonomously for up to 72
hours.

**Rationale:** The USGS wants all ground segment operations to support
this staffing profile in support of operations cost targets.

### Mission Data Return Connection

**GNE436:** The GNE shall provide network connection from each LGN
station to the DCRS (Interval Routing).

**Rationale:** In support of the mission data transfer to DPAS. This
includes bidirectional communications between the LGN stations and the
DCRS IR.

**GNE409:** The GNE shall provide network connections between DCRS (File
Routing) to DCRS (Interval Routing) with a capacity of 450 GB (TBC) in a
24 hour period.

**Rationale:** Increased capacity to support GSRD minimums - the 450 GB
is an estimated amount based on current data probabilities

### Telemetry and Command Connection

**GNE236:** The GNE shall provide network connection for the transfer of
the telemetry data between the MOE and all LGN stations.

**Rationale:** This (TBD) capacity is needed in order to make real time
data transfer in nominal mission mode.

**GNE670:** The GNE shall provide network connection for the transfer of
the command uplink data between the MOE and all LGN stations.

**Rationale:** This (TBD) capacity is needed in order to make real time
data transfer in nominal mission mode.

**GNE647:** The GNE shall forward the real-time telemetry to the MOE in
real-time.

**Rationale:** Minimal delay of real-time telemetry to maximize
efficiency of station contacts. This time begins when the last RF symbol
of a transfer frame is received and ends when the first bit of the
encapsulated packet hits the WAN pipe. It does not include the WAN
transfer time.

**GNE648:** The GNE shall forward the real-time telemetry to the bMOE in
real-time.

**Rationale:** Minimal delay of real-time telemetry to maximize
efficiency of station contacts. This time begins when the last RF symbol
of a transfer frame is received and ends when the first bit of the
encapsulated packet hits the WAN pipe. It does not include the WAN
transfer time.

**GNE269:** The GNE shall provide network connections for telemetry and
command with an availability of 99.9% over a 30 day period.

**Rationale:** Supports GS165 for the command uplink and telemetry
downlink criticality.

### Scheduling and Reporting Connection

**GNE270:** The GNE shall provide network connection for scheduling and
reporting with an availability of 99.9% over a 30 day period.

**Rationale:** The requirement supports the GS requirement for reporting
in GS165.

**GNE590:** The GNE shall provide network connectivity between all LGN
stations and the SRS.

**Rationale:** In support of scheduling and status report data transfer.

## Interfaces

### External GNE Interfaces

####  Missions Operations Center (MOC)

**GNE607:** The GNE shall receive contact forecast requests from the
MOE.

**Rationale:** The MOE uses its FD to determine contact schedule and
sends selected set to GNE for confirmation.

**GNE608:** The GNE shall make available the contact forecast
confirmation to the MOE within 24 hours of request.

**Rationale:** This is the response and completion of the contact
forecast request from the MOE. It will outline the potential LGN, assets
and configurations that would be utilized for any given pass event in
the forecast request.

**GNE609:** The GNE shall receive the confirmed contact schedule from
the MOE.

**Rationale:** The MOE uses its FD to determine contact schedule and
sends selected set to GNE for confirmation.

**GNE610:** The GNE shall receive the acquisition data (IIRV) from the
MOE.

**Rationale:** Compatibility with present practice and LDCM MOE
operations concept (IIRV).

**GNE611:** The GNE shall provide bidirectional messaging and
confirmation to the MOE.

**Rationale:** Bidirectional messaging is necessary to perform MOC
operational needs.

**GNE612:** The GNE shall provide CFDP status messages to the MOE.

**Rationale:** This information is important for MOC troubleshooting of
observatory performance as well as GNE operations and maintenance
troubleshooting.

**GNE613:** The GNE shall provide the mission data directory information
to the MOE.

**Rationale:** The mission data directory contents come from the DCRS
and are sent to the MOE to aid in memory management of the Observatory.
The current implementation thought would be to have this done on a timed
interval or from a message request.

**GNE614:** The GNE shall receive the interval to file mapping tables
from the MOE.

**Rationale:** In preservation of spacecraft physical security. This
applies to LDCM inputs for the LDCM Observatory it does not preclude
multi-mission support.

**GNE615:** The GNE shall provide GSE real-time status to the MOE.

**Rationale:** In support of GNE operations and maintenance staff
troubleshooting and GNE to MOE interface agreement.

**GNE616:** The GNE shall provide a post-pass event report to the MOE.

**Rationale:** Used for closing the loop on file downlink status with
MOE for subsequent retransmission or deletion.

**GNE617:** The GNE shall receive GSE directives from the MOE.

**Rationale:** The directives would be received by the SRS in relation
to the current pass event. An example would be changing the received
telemetry rate for the S-Band equipment in the LGN station.

**GNE618:** The GNE shall receive the command uplink from the MOE.

**Rationale:** In preservation of spacecraft physical security. This
applies to LDCM inputs for the LDCM Observatory it does not preclude
multi-mission support.

**GNE619:** The GNE shall send the received S-Band real-time telemetry
to the MOE.

**Rationale:** This information is important for MOC troubleshooting of
observatory performance as well as GNE operations and maintenance
troubleshooting.

**GNE620:** The GNE shall send the received S-Band play-back telemetry
to the MOE.

**Rationale:** Since stored telemetry transfer could potentially take
hours, this capability is required.

####  Storage and Archive Element (SAE)

**GNE625:** The GNE shall transfer complete mission data intervals to
the SAE.

**Rationale:** IPE must have all the files comprising an interval before
the ingest and processing algorithms can be run. This only means holding
individual files until all the files from the same interval are
together, and transferring all the files as a group. No data processing
is implied. (An interval is a continuous data collection.)

####  Ingest and Processing Element (IPE)

**GNE621:** The GNE shall notify the IPE IS that an interval has been
delivered.

**Rationale:** Notification to the IPE will utilize the SOA from the IE.
The notification will consist of several pieces of information about the
files and the interval, to include its location on the SAE internal
cache.

**GNE622:** The GNE shall receive ingest confirmation messages from the
IPE.

**Rationale:** The ingest confirmation message will allow the GNE to
flag the data as successfully ingested and mark it for future deletion.

**GNE623:** The GNE shall receive mission data retransmit requests from
the IPE.

**Rationale:** Interface allowing the retransmission of data to the SAE
and re-notification of the IPE the data has been delivered. The
retransmission implies versioning of the interval at some level which
has not been defined.

####  Observatory

**GNE628:** The GNE shall transmit the command uplink to the
observatory.

**Rationale:** This interface is required for telemetry, commanding and
science data to flow through GNE.

**GNE629:** The GNE shall receive the real-time telemetry downlink from
the observatory.

**Rationale:** Compatibility with observatory RD stated capability.

**GNE630:** The GNE shall receive the play-back telemetry downlink from
the observatory.

**Rationale:** Compatibility with observatory RD stated capability.

**GNE631:** The GNE shall receive the mission data files from the
observatory.

**Rationale:** A non-proprietary standard was chosen based on
availability of COTS receiving hardware/software for LGN and IC
stations. This file-based protocol supports the file-based onboard
storage requirements.

####  Infrastructure Element

**GNE627:** The GNE shall provide communication compatibility to the IE
for element to element communications.

**Rationale:**

####  GNE Operations Staff

**GNE632:** The GNE shall provide manual interfaces for the operations
staff.

**Rationale:**

**GNE633:** The GNE shall provide status to the operations staff for all
GNE equipment.

**Rationale:**

####  International Cooperators (IC)

**GNE634:** The GNE shall receive mission data files from IC stations in
accordance with the DFCB (TBD).

**Rationale:** In support of station validation and IC data validation
and evaluation activities.

# Appendix A: Allocations

![](media/image4.wmf)

# Appendix B: Traceability Matrix

+-----------------------------+----------------------------------------+
| **GNE ID**                  | **GSRD ID**                            |
+=============================+========================================+
| GNE652                      | GS162                                  |
+-----------------------------+----------------------------------------+
| GNE639                      | GS165                                  |
|                             |                                        |
|                             | GS623                                  |
+-----------------------------+----------------------------------------+
| GNE269                      | GS165                                  |
+-----------------------------+----------------------------------------+
| GNE270                      | GS165                                  |
+-----------------------------+----------------------------------------+
| GNE346                      | GS1682                                 |
+-----------------------------+----------------------------------------+
| GNE170                      | GS1682                                 |
+-----------------------------+----------------------------------------+
| GNE581                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE477                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE129                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE147                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE150                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE151                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE278                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE196                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE559                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE591                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE625                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE621                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE622                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE623                      | GS1745                                 |
+-----------------------------+----------------------------------------+
| GNE146                      | GS177                                  |
+-----------------------------+----------------------------------------+
| GNE643                      | GS181                                  |
+-----------------------------+----------------------------------------+
| GNE552                      | GS1843                                 |
|                             |                                        |
|                             | GS1844                                 |
+-----------------------------+----------------------------------------+
| GNE572                      | GS1843                                 |
|                             |                                        |
|                             | GS1844                                 |
+-----------------------------+----------------------------------------+
| GNE171                      | GS1843                                 |
|                             |                                        |
|                             | GS1844                                 |
+-----------------------------+----------------------------------------+
| GNE667                      | GS1844                                 |
+-----------------------------+----------------------------------------+
| GNE668                      | GS1844                                 |
+-----------------------------+----------------------------------------+
| GNE589                      | GS26                                   |
+-----------------------------+----------------------------------------+
| GNE474                      | GS2830                                 |
+-----------------------------+----------------------------------------+
| GNE651                      | GS532                                  |
+-----------------------------+----------------------------------------+
| GNE379                      | GS532                                  |
|                             |                                        |
|                             | GS623                                  |
+-----------------------------+----------------------------------------+
| GNE575                      | GS532                                  |
+-----------------------------+----------------------------------------+
| GNE425                      | GS532                                  |
+-----------------------------+----------------------------------------+
| GNE250                      | GS534                                  |
+-----------------------------+----------------------------------------+
| GNE253                      | GS539                                  |
|                             |                                        |
|                             | GS656                                  |
+-----------------------------+----------------------------------------+
| GNE548                      | GS540                                  |
+-----------------------------+----------------------------------------+
| GNE549                      | GS540                                  |
+-----------------------------+----------------------------------------+
| GNE282                      | GS540                                  |
+-----------------------------+----------------------------------------+
| GNE669                      | GS540                                  |
+-----------------------------+----------------------------------------+
| GNE169                      | GS540                                  |
+-----------------------------+----------------------------------------+
| GNE372                      | GS540                                  |
+-----------------------------+----------------------------------------+
| GNE164                      | GS540                                  |
+-----------------------------+----------------------------------------+
| GNE607                      | GS540                                  |
+-----------------------------+----------------------------------------+
| GNE609                      | GS540                                  |
+-----------------------------+----------------------------------------+
| GNE262                      | GS543                                  |
+-----------------------------+----------------------------------------+
| GNE263                      | GS543                                  |
+-----------------------------+----------------------------------------+
| GNE88                       | GS543                                  |
+-----------------------------+----------------------------------------+
| GNE648                      | GS543                                  |
+-----------------------------+----------------------------------------+
| GNE611                      | GS543                                  |
|                             |                                        |
|                             | GS544                                  |
|                             |                                        |
|                             | GS666                                  |
+-----------------------------+----------------------------------------+
| GNE92                       | GS544                                  |
+-----------------------------+----------------------------------------+
| GNE647                      | GS544                                  |
+-----------------------------+----------------------------------------+
| GNE629                      | GS544                                  |
|                             |                                        |
|                             | GS662                                  |
+-----------------------------+----------------------------------------+
| GNE532                      | GS545                                  |
+-----------------------------+----------------------------------------+
| GNE561                      | GS545                                  |
+-----------------------------+----------------------------------------+
| GNE126                      | GS545                                  |
+-----------------------------+----------------------------------------+
| GNE553                      | GS545                                  |
+-----------------------------+----------------------------------------+
| GNE615                      | GS545                                  |
+-----------------------------+----------------------------------------+
| GNE73                       | GS546                                  |
+-----------------------------+----------------------------------------+
| GNE87                       | GS547                                  |
+-----------------------------+----------------------------------------+
| GNE398                      | GS547                                  |
+-----------------------------+----------------------------------------+
| GNE396                      | GS548                                  |
+-----------------------------+----------------------------------------+
| GNE400                      | GS548                                  |
+-----------------------------+----------------------------------------+
| GNE401                      | GS549                                  |
+-----------------------------+----------------------------------------+
| GNE492                      | GS550                                  |
+-----------------------------+----------------------------------------+
| GNE77                       | GS550                                  |
+-----------------------------+----------------------------------------+
| GNE78                       | GS550                                  |
+-----------------------------+----------------------------------------+
| GNE496                      | GS551                                  |
+-----------------------------+----------------------------------------+
| GNE497                      | GS552                                  |
+-----------------------------+----------------------------------------+
| GNE75                       | GS553                                  |
+-----------------------------+----------------------------------------+
| GNE294                      | GS554                                  |
+-----------------------------+----------------------------------------+
| GNE520                      | GS555                                  |
+-----------------------------+----------------------------------------+
| GNE519                      | GS556                                  |
+-----------------------------+----------------------------------------+
| GNE357                      | GS557                                  |
|                             |                                        |
|                             | GS1843                                 |
|                             |                                        |
|                             | GS1844                                 |
+-----------------------------+----------------------------------------+
| GNE666                      | GS557                                  |
+-----------------------------+----------------------------------------+
| GNE619                      | GS557                                  |
|                             |                                        |
|                             | GS666                                  |
+-----------------------------+----------------------------------------+
| GNE239                      | GS558                                  |
+-----------------------------+----------------------------------------+
| GNE570                      | GS558                                  |
+-----------------------------+----------------------------------------+
| GNE612                      | GS558                                  |
+-----------------------------+----------------------------------------+
| GNE110                      | GS559                                  |
+-----------------------------+----------------------------------------+
| GNE107                      | GS560                                  |
+-----------------------------+----------------------------------------+
| GNE243                      | GS560                                  |
+-----------------------------+----------------------------------------+
| GNE245                      | GS562                                  |
+-----------------------------+----------------------------------------+
| GNE106                      | GS563                                  |
+-----------------------------+----------------------------------------+
| GNE491                      | GS564                                  |
+-----------------------------+----------------------------------------+
| GNE512                      | GS566                                  |
+-----------------------------+----------------------------------------+
| GNE511                      | GS567                                  |
+-----------------------------+----------------------------------------+
| GNE489                      | GS567                                  |
+-----------------------------+----------------------------------------+
| GNE493                      | GS568                                  |
+-----------------------------+----------------------------------------+
| GNE279                      | GS568                                  |
+-----------------------------+----------------------------------------+
| GNE114                      | GS592                                  |
+-----------------------------+----------------------------------------+
| GNE631                      | GS592                                  |
+-----------------------------+----------------------------------------+
| GNE495                      | GS593                                  |
+-----------------------------+----------------------------------------+
| GNE480                      | GS595                                  |
+-----------------------------+----------------------------------------+
| GNE74                       | GS650                                  |
+-----------------------------+----------------------------------------+
| GNE84                       | GS654                                  |
+-----------------------------+----------------------------------------+
| GNE86                       | GS654                                  |
+-----------------------------+----------------------------------------+
| GNE336                      | GS655                                  |
+-----------------------------+----------------------------------------+
| GNE550                      | GS657                                  |
+-----------------------------+----------------------------------------+
| GNE176                      | GS657                                  |
+-----------------------------+----------------------------------------+
| GNE173                      | GS657                                  |
+-----------------------------+----------------------------------------+
| GNE174                      | GS657                                  |
+-----------------------------+----------------------------------------+
| GNE608                      | GS657                                  |
+-----------------------------+----------------------------------------+
| GNE613                      | GS657                                  |
+-----------------------------+----------------------------------------+
| GNE614                      | GS657                                  |
+-----------------------------+----------------------------------------+
| GNE617                      | GS657                                  |
+-----------------------------+----------------------------------------+
| GNE618                      | GS657                                  |
|                             |                                        |
|                             | GS666                                  |
+-----------------------------+----------------------------------------+
| GNE210                      | GS66                                   |
+-----------------------------+----------------------------------------+
| GNE237                      | GS66                                   |
|                             |                                        |
|                             | GS666                                  |
+-----------------------------+----------------------------------------+
| GNE236                      | GS66                                   |
+-----------------------------+----------------------------------------+
| GNE670                      | GS66                                   |
+-----------------------------+----------------------------------------+
| GNE628                      | GS66                                   |
+-----------------------------+----------------------------------------+
| GNE209                      | GS661                                  |
+-----------------------------+----------------------------------------+
| GNE44                       | GS662                                  |
+-----------------------------+----------------------------------------+
| GNE494                      | GS662                                  |
+-----------------------------+----------------------------------------+
| GNE72                       | GS662                                  |
+-----------------------------+----------------------------------------+
| GNE76                       | GS662                                  |
+-----------------------------+----------------------------------------+
| GNE81                       | GS662                                  |
+-----------------------------+----------------------------------------+
| GNE95                       | GS662                                  |
+-----------------------------+----------------------------------------+
| GNE630                      | GS662                                  |
+-----------------------------+----------------------------------------+
| GNE235                      | GS664                                  |
+-----------------------------+----------------------------------------+
| GNE91                       | GS664                                  |
+-----------------------------+----------------------------------------+
| GNE620                      | GS666                                  |
+-----------------------------+----------------------------------------+
| GNE436                      | GS669                                  |
+-----------------------------+----------------------------------------+
| GNE409                      | GS669                                  |
+-----------------------------+----------------------------------------+
| GNE513                      | GS70                                   |
+-----------------------------+----------------------------------------+
| GNE482                      | GS70                                   |
+-----------------------------+----------------------------------------+
| GNE483                      | GS70                                   |
+-----------------------------+----------------------------------------+
| GNE514                      | GS70                                   |
+-----------------------------+----------------------------------------+
| GNE162                      | GS73                                   |
+-----------------------------+----------------------------------------+
| GNE634                      | GS73                                   |
+-----------------------------+----------------------------------------+
| GNE569                      | GS74                                   |
|                             |                                        |
|                             | GS89                                   |
|                             |                                        |
|                             | GS557                                  |
|                             |                                        |
|                             | GS558                                  |
+-----------------------------+----------------------------------------+
| GNE345                      | GS74                                   |
|                             |                                        |
|                             | GS557                                  |
|                             |                                        |
|                             | GS558                                  |
+-----------------------------+----------------------------------------+
| GNE616                      | GS74                                   |
+-----------------------------+----------------------------------------+
| GNE311                      | GS75                                   |
+-----------------------------+----------------------------------------+
| GNE428                      | GS75                                   |
+-----------------------------+----------------------------------------+
| GNE248                      | GS77                                   |
+-----------------------------+----------------------------------------+
| GNE167                      | GS77                                   |
+-----------------------------+----------------------------------------+
| GNE590                      | GS77                                   |
|                             |                                        |
|                             | GS540                                  |
|                             |                                        |
|                             | GS661                                  |
+-----------------------------+----------------------------------------+
| GNE85                       | GS79                                   |
|                             |                                        |
|                             | GS534                                  |
+-----------------------------+----------------------------------------+
| GNE351                      | GS79                                   |
+-----------------------------+----------------------------------------+
| GNE28                       | GS802                                  |
+-----------------------------+----------------------------------------+
| GNE642                      | GS804                                  |
+-----------------------------+----------------------------------------+
| GNE473                      | GS84                                   |
+-----------------------------+----------------------------------------+
| GNE481                      | GS88                                   |
+-----------------------------+----------------------------------------+
| GNE177                      | GS88                                   |
+-----------------------------+----------------------------------------+
| GNE175                      | GS88                                   |
+-----------------------------+----------------------------------------+
| GNE610                      | GS88                                   |
+-----------------------------+----------------------------------------+
| GNE571                      | GS89                                   |
+-----------------------------+----------------------------------------+
| GNE283                      | GS89                                   |
|                             |                                        |
|                             | GS1843                                 |
|                             |                                        |
|                             | GS1844                                 |
+-----------------------------+----------------------------------------+
| GNE557                      | GS89                                   |
+-----------------------------+----------------------------------------+
| GNE587                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE654                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE655                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE656                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE657                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE658                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE659                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE660                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE661                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE662                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE671                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE673                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE672                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE674                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE675                      | GS930                                  |
+-----------------------------+----------------------------------------+
| GNE293                      | GS942                                  |
+-----------------------------+----------------------------------------+

# Appendix C: Verification Matrix

  ------------------------------------------------------------------------------
  **ID**                                      **Verification**
  ------------------------------------ ------ ----------------------------------
  GNE28                                       Analysis

  GNE269                                      Analysis

  GNE270                                      Analysis

  GNE209                                      Demonstration

  GNE481                                      Demonstration

  GNE346                                      Demonstration

  GNE425                                      Demonstration

  GNE587                                      Inspection

  GNE654                                      Inspection

  GNE655                                      Inspection

  GNE656                                      Inspection

  GNE657                                      Inspection

  GNE658                                      Inspection

  GNE659                                      Inspection

  GNE660                                      Inspection

  GNE661                                      Inspection

  GNE662                                      Inspection

  GNE671                                      Inspection

  GNE673                                      Inspection

  GNE672                                      Inspection

  GNE674                                      Inspection

  GNE675                                      Inspection

  GNE293                                      Inspection

  GNE311                                      Inspection

  GNE468                                      Test

  GNE469                                      Test

  GNE644                                      Test

  GNE474                                      Test

  GNE646                                      Test

  GNE650                                      Test

  GNE651                                      Test

  GNE652                                      Test

  GNE639                                      Test

  GNE44                                       Test

  GNE210                                      Test

  GNE262                                      Test

  GNE263                                      Test

  GNE94                                       Test

  GNE237                                      Test

  GNE235                                      Test

  GNE253                                      Test

  GNE250                                      Test

  GNE480                                      Test

  GNE513                                      Test

  GNE482                                      Test

  GNE483                                      Test

  GNE532                                      Test

  GNE514                                      Test

  GNE493                                      Test

  GNE491                                      Test

  GNE511                                      Test

  GNE489                                      Test

  GNE512                                      Test

  GNE494                                      Test

  GNE495                                      Test

  GNE519                                      Test

  GNE520                                      Test

  GNE496                                      Test

  GNE497                                      Test

  GNE72                                       Test

  GNE492                                      Test

  GNE73                                       Test

  GNE641                                      Test

  GNE74                                       Test

  GNE294                                      Test

  GNE75                                       Test

  GNE76                                       Test

  GNE77                                       Test

  GNE78                                       Test

  GNE81                                       Test

  GNE84                                       Test

  GNE85                                       Test

  GNE351                                      Test

  GNE86                                       Test

  GNE87                                       Test

  GNE396                                      Test

  GNE88                                       Test

  GNE91                                       Test

  GNE92                                       Test

  GNE95                                       Test

  GNE561                                      Test

  GNE126                                      Test

  GNE223                                      Test

  GNE224                                      Test

  GNE398                                      Test

  GNE400                                      Test

  GNE401                                      Test

  GNE106                                      Test

  GNE279                                      Test

  GNE107                                      Test

  GNE110                                      Test

  GNE336                                      Test

  GNE114                                      Test

  GNE569                                      Test

  GNE239                                      Test

  GNE242                                      Test

  GNE243                                      Test

  GNE245                                      Test

  GNE345                                      Test

  GNE570                                      Test

  GNE571                                      Test

  GNE548                                      Test

  GNE549                                      Test

  GNE550                                      Test

  GNE552                                      Test

  GNE553                                      Test

  GNE572                                      Test

  GNE248                                      Test

  GNE379                                      Test

  GNE357                                      Test

  GNE666                                      Test

  GNE667                                      Test

  GNE668                                      Test

  GNE283                                      Test

  GNE282                                      Test

  GNE669                                      Test

  GNE177                                      Test

  GNE176                                      Test

  GNE175                                      Test

  GNE173                                      Test

  GNE174                                      Test

  GNE171                                      Test

  GNE170                                      Test

  GNE169                                      Test

  GNE167                                      Test

  GNE372                                      Test

  GNE164                                      Test

  GNE575                                      Test

  GNE428                                      Test

  GNE581                                      Test

  GNE576                                      Test

  GNE473                                      Test

  GNE162                                      Test

  GNE477                                      Test

  GNE557                                      Test

  GNE146                                      Test

  GNE642                                      Test

  GNE643                                      Test

  GNE129                                      Test

  GNE147                                      Test

  GNE150                                      Test

  GNE151                                      Test

  GNE278                                      Test

  GNE196                                      Test

  GNE559                                      Test

  GNE591                                      Test

  GNE589                                      Test

  GNE436                                      Test

  GNE409                                      Test

  GNE236                                      Test

  GNE670                                      Test

  GNE647                                      Test

  GNE648                                      Test

  GNE590                                      Test

  GNE607                                      Test

  GNE608                                      Test

  GNE609                                      Test

  GNE610                                      Test

  GNE611                                      Test

  GNE612                                      Test

  GNE613                                      Test

  GNE614                                      Test

  GNE615                                      Test

  GNE616                                      Test

  GNE617                                      Test

  GNE618                                      Test

  GNE619                               Test   

  GNE620                               Test   

  GNE625                               Test   

  GNE621                               Test   

  GNE622                               Test   

  GNE623                               Test   

  GNE628                               Test   

  GNE629                               Test   

  GNE630                               Test   

  GNE631                               Test   

  GNE626                               Test   

  GNE627                               Test   

  GNE601                               Test   

  GNE632                               Test   

  GNE633                               Test   

  GNE602                               Test   

  GNE634                               Test   

  GNE665                               Test   
  ------------------------------------------------------------------------------

# Appendix D: Priority Matrix

  -----------------------------------------------------------------------
  **GNE ID**                       **Priority**
  -------------------------------- --------------------------------------
  GNE293                           Priority 1

  GNE44                            Priority 1

  GNE210                           Priority 1

  GNE262                           Priority 1

  GNE263                           Priority 1

  GNE237                           Priority 1

  GNE253                           Priority 1

  GNE480                           Priority 1

  GNE481                           Priority 1

  GNE483                           Priority 1

  GNE532                           Priority 1

  GNE493                           Priority 1

  GNE491                           Priority 1

  GNE511                           Priority 1

  GNE489                           Priority 1

  GNE512                           Priority 1

  GNE494                           Priority 1

  GNE495                           Priority 1

  GNE496                           Priority 1

  GNE497                           Priority 1

  GNE72                            Priority 1

  GNE492                           Priority 1

  GNE73                            Priority 1

  GNE641                           Priority 1

  GNE74                            Priority 1

  GNE294                           Priority 1

  GNE75                            Priority 1

  GNE76                            Priority 1

  GNE77                            Priority 1

  GNE78                            Priority 1

  GNE84                            Priority 1

  GNE92                            Priority 1

  GNE95                            Priority 1

  GNE561                           Priority 1

  GNE126                           Priority 1

  GNE223                           Priority 1

  GNE224                           Priority 1

  GNE398                           Priority 1

  GNE400                           Priority 1

  GNE401                           Priority 1

  GNE106                           Priority 1

  GNE279                           Priority 1

  GNE107                           Priority 1

  GNE110                           Priority 1

  GNE114                           Priority 1

  GNE242                           Priority 1

  GNE245                           Priority 1

  GNE553                           Priority 1

  GNE589                           Priority 1

  GNE236                           Priority 1

  GNE611                           Priority 1

  GNE612                           Priority 1

  GNE615                           Priority 1

  GNE628                           Priority 1

  GNE629                           Priority 1

  GNE630                           Priority 1

  GNE631                           Priority 1

  GNE468                           Priority 2

  GNE469                           Priority 2

  GNE644                           Priority 2

  GNE474                           Priority 2

  GNE28                            Priority 2

  GNE646                           Priority 2

  GNE587                           Priority 2

  GNE654                           Priority 2

  GNE655                           Priority 2

  GNE656                           Priority 2

  GNE657                           Priority 2

  GNE658                           Priority 2

  GNE659                           Priority 2

  GNE660                           Priority 2

  GNE661                           Priority 2

  GNE662                           Priority 2

  GNE671                           Priority 2

  GNE673                           Priority 2

  GNE672                           Priority 2

  GNE674                           Priority 2

  GNE675                           Priority 2

  GNE650                           Priority 2

  GNE651                           Priority 2

  GNE652                           Priority 2

  GNE209                           Priority 2

  GNE639                           Priority 2

  GNE94                            Priority 2

  GNE235                           Priority 2

  GNE250                           Priority 2

  GNE513                           Priority 2

  GNE482                           Priority 2

  GNE514                           Priority 2

  GNE519                           Priority 2

  GNE520                           Priority 2

  GNE81                            Priority 2

  GNE85                            Priority 2

  GNE351                           Priority 2

  GNE86                            Priority 2

  GNE87                            Priority 2

  GNE396                           Priority 2

  GNE88                            Priority 2

  GNE91                            Priority 2

  GNE336                           Priority 2

  GNE569                           Priority 2

  GNE239                           Priority 2

  GNE243                           Priority 2

  GNE345                           Priority 2

  GNE570                           Priority 2

  GNE571                           Priority 2

  GNE548                           Priority 2

  GNE549                           Priority 2

  GNE550                           Priority 2

  GNE552                           Priority 2

  GNE572                           Priority 2

  GNE346                           Priority 2

  GNE379                           Priority 2

  GNE357                           Priority 2

  GNE666                           Priority 2

  GNE667                           Priority 2

  GNE668                           Priority 2

  GNE283                           Priority 2

  GNE282                           Priority 2

  GNE669                           Priority 2

  GNE177                           Priority 2

  GNE176                           Priority 2

  GNE175                           Priority 2

  GNE173                           Priority 2

  GNE174                           Priority 2

  GNE171                           Priority 2

  GNE170                           Priority 2

  GNE169                           Priority 2

  GNE167                           Priority 2

  GNE372                           Priority 2

  GNE164                           Priority 2

  GNE575                           Priority 2

  GNE581                           Priority 2

  GNE576                           Priority 2

  GNE473                           Priority 2

  GNE477                           Priority 2

  GNE557                           Priority 2

  GNE146                           Priority 2

  GNE642                           Priority 2

  GNE643                           Priority 2

  GNE129                           Priority 2

  GNE147                           Priority 2

  GNE150                           Priority 2

  GNE151                           Priority 2

  GNE278                           Priority 2

  GNE196                           Priority 2

  GNE559                           Priority 2

  GNE591                           Priority 2

  GNE436                           Priority 2

  GNE409                           Priority 2

  GNE670                           Priority 2

  GNE647                           Priority 2

  GNE648                           Priority 2

  GNE269                           Priority 2

  GNE270                           Priority 2

  GNE590                           Priority 2

  GNE607                           Priority 2

  GNE608                           Priority 2

  GNE609                           Priority 2

  GNE610                           Priority 2

  GNE613                           Priority 2

  GNE614                           Priority 2

  GNE616                           Priority 2

  GNE617                           Priority 2

  GNE618                           Priority 2

  GNE619                           Priority 2

  GNE620                           Priority 2

  GNE625                           Priority 2

  GNE621                           Priority 2

  GNE622                           Priority 2

  GNE623                           Priority 2

  GNE626                           Priority 2

  GNE627                           Priority 2

  GNE601                           Priority 2

  GNE632                           Priority 2

  GNE633                           Priority 2

  GNE602                           Priority 2

  GNE665                           Priority 2

  GNE311                           Priority 3

  GNE248                           Priority 3

  GNE428                           Priority 3

  GNE162                           Priority 3

  GNE425                           Priority 3

  GNE634                           Priority 3
  -----------------------------------------------------------------------

# Appendix E: Acronyms

  ------------- ----------------------------------------------------------
  **Acronym**   **Description**

  bMOE          backup Mission Operations Element

  bps           bits per second

  BPSK          Band Phase Shift Keying

  BPSK          Binary Phase Shift Keyed

  CCSDS         Consultative Committee for Space Data Systems

  CFDP          CCSDS File Delivery Protocol

  CONUS         CONterminous United States

  COTS          Commercial Off The Shelf

  dB/K          Decibel /Kelvin

  dBW           Decibel Watt

  DCPF          Data Capture and Processing Facility

  DCRS          Data Collection and Routing System

  DCRS (FR)     Data Collection and Routing System (File Routing)

  DCRS (IR)     Data Collection and Routing System (Interval Routing)

  DFCB          Data Format Control Book

  DPAS          Data Processing and Archive Segment

  EIRP          Effective Isotropic Radiated Power

  EROS          Earth Resources Observation and Science

  FD            Flight Dynamics

  FOT           Flight Operations Team

  G/T           Gain Vs system thermal noise Temperature dB/K

  GN            Ground Network

  GNE           Ground Network Element

  GRT           Ground Readiness Test

  GSC           Ground Station Control

  GSE           Ground Station Equipment

  GSFC          Goddard Space Flight Center

  GSRD          Ground System Requirements Document

  I&T           Integration & Testing

  IC            International Cooperators

  ICD           Interface Control Document

  IIRV          Improved Inter-Range Vector

  IOC           Initial Operating Capability

  IPE           Image Processing Element

  IPE IS        IPE Ingest Subsystem

  IT            Information Technology

  Kbps          Kilo bits per second

  LGN           LDCM Ground Network

  LHCP          Left Hand Circular Polarization

  Mbps          Mega bits per second

  MHz           Mega Hertz

  MOC           Mission Operations Center

  MOE           Mission Operations Element

  MOERD         Mission Operations Element Requirements Document

  MRT           Mission Readiness Test

  OAR           On-Orbit Acceptance Review

  OIRD          Observatory Interface Requirements Document

  RF            Radio Frequency

  RHCP          Right Hand Circular Polarization

  RS            Reed Solomon

  RSDO          Rapid Spacecraft Development Office

  SAE           Storage and Archive Element

  SN            Space Network

  SOP           Standard Operating Procedures

  SRS           Scheduling and Reporting System

  SSR           Solid State Recorder

  TBC           To Be Confirmed

  TBD           To Be Defined

  TBR           To Be Reviewed

  TDRSS         Tracking Data Relay Satellite System

  TLE           Two Line Element

  TM            TeleMetry

  UPE           User Portal Element

  USGS          United States Geological Survey
  ------------- ----------------------------------------------------------