IGS Overview Brief for Sources Sought RFI 10 Dec 25.pptx

Next Generation Ionosonde (NEXION) & Ionospheric Scintillation Total electron content (TEC) Observer (ISTO)

10 Dec 2025 Ionsopheric Ground Sensors (IGS)

Mission/Purpose of IGS IGS Mission and Support to USSF IGS program office installs and sustains Ionospheric Ground Sensors around the globe that characterize the space weather environment Ground sensors consist of:

NEXION

ISTO

Data remotely collected by sensors and forwarded The SWAFS/SET4D program uses the data to create various model output and warfighter products that characterize and forecast global ionospheric conditions Products are used to mitigate current/predicted impacts to High Frequency (HF) comms, Ultra High Frequency (UHF) systems, radar systems, collection activities, and Global Positioning System (GPS) services via the Space Weather Analysis and Forecast System (SWAFS)/Space Domain Awareness (SDA) Environmental Toolkit – 4 Defense (SET-4D)

NEXION

Mission/Purpose of NEXION Unclassified, Commercial-off-the-Shelf (COTS), Unmanned vertical incidence radar Collects bottom side ionospheric measurements Transmitter sweeps through the high frequency radio bands System analyzes the signals reflected from the ionosphere producing an electron density profile It then sends data via the Non-Classified Internet Protocol Router Network (NIPRNET) The SWAFS/SET4D program pulls this data to be used in ionospheric models

NEXION System Parameters Global coverage of the earth’s ionosphere: 60-1500Km Two 150-Watt low power solid-state transmitters Transmitting range 2 MHz to 30 MHz; Avg. output 16 Watts per transmitter Provide Electron Density Profiles that give:

Height Range and Resolution Density Range and Resolution Data Latency – deliver the analyzed data to GIG Threshold 15 Min./Objective 5 Min.

Unattended system Built in Test (BIT) for diagnostics

NEXION Operations and Data Flow Ionosphere NIPRNet / Internet

NEXION System Data

DPS-4D

Receive Antenna

Transmit Antenna

Remote Access

NEXION System Hardware

Receive Antenna (Four antennas)

DPS-4D

Ionospheric Sounder Obstruction Lights

APC Smart-UPS

SMX 2200VA RM 2U 120V

GPS Acutime Gold Antenna

Surge Suppression Panel

Sensaphone Environmental/Hardware Monitoring

Transmit Antenna (101ft tower w/dual elements)

Transmitter Layout

42m Square area to support tower and guy wires 101ft Tx Tower

Receiver Antenna Field Layout

60 m Equilateral triangle (ideal) 45 m Equilateral triangle (min) Receiver Antenna

Shelter/Control Center Layout

Equipment Shelter

Standard NEXION shelter is 8’ x 10’ Desk (if required) is 52”x32”x29.5” (WxDxH)

ISTO

Mission/Purpose of ISTO Unclassified, Unmanned, Remotely Operated, Receive-only Sensor situated along the magnetic equator

Utilizes Commercial-off-the-Shelf (COTS) Hardware and a mixture of COTS and Government off the Shelf (GOTS) software to provide ionospheric characterization data using GPS and UHF receivers

Measures the impacts of Ionospheric Scintillation on UHF and GPS signals Measures S4 (ionospheric scintillation parameter) Measures Total Electron Content (TEC) of the Ionosphere Sends data for space environmental model input

ISTO is a configuration-controlled version of the Air Force Research Laboratory (AFRL) Scintillation Decision Aid (SCINDA) system.

ISTO Operations and Data Flow

Ionosphere

NIPRNET

UHF Satellite

GPS

ISTO

Processor 2 Yagi Antennas

GPS

Antenna

One GPS antenna (ground or roof-mounted)

Two Yagi antennas (ground or roof-mounted) Indoor Equipment Rack

ISTO = Ionospheric Scintillation Total Electron Content (TEC) Observer

ISTO System Hardware

ISTO Questions and Answers Question #1 How much outdoor space does ISTO need?

Answer #1 3 Antennas mounted outdoors (1 GPS, 2 Yagi antennas) Each antenna mount has a 3ft x 3ft footprint Can be ground or roof-mounted

Yagi Antenna GPS Antenna

ISTO Questions and Answers Question #2 How much indoor space does ISTO need?

Answer #2 Equipment rack is a 38U server rack Footprint is 36”L x 24”W x 72”H We request space to install the equipment rack in a suitable building at AB201, such as a server room or a comm closet

Question #3 What are ISTO’s power requirements?

Answer #3 One 30-Amp circuit, 120V, 60 Hz AC

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