Transmission and User Requirements Technology for eLoran ...

Shared interest in a more productive tomorrow.

Presented by:

Mr. Charles Schue, President & CEO

Mr. John Hartline, Senior Director, Product Solutions

July 14, 2011

Transmission and User Requirements Technology for eLoran

(eLoran의 송신기술 및 수신기 기술)

- Public Version -

EMEA Operations

Bertem, Belgium

Corporate Headquarters

Chesapeake, Virginia

Washington DC Metropolitan Area

Leesburg, Virginia

• Low Frequency (LF) Alternative PNT&D

• Fixed Site Solutions

– eLoran System

– Representative Requirements

– Representative Equipment

– Scenarios for Signal Strength and Accuracy

• Small Footprint Solutions

– Tactical, Temporary, Transportable

• The Future – Now!

– LFPhoenix™ and Beyond

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

•Loran-C•PNT service in use in many parts of the northern hemisphere

•eLoran•PNT & Data service•aka “TerraNav”•Partially deployed: USA/UK

•Tactical LF•Deployable LF Alternative PNT&D service•Loran, eLoran, TerraNav, LFPhoenix™, new initiatives

•LFPhoenix™•Alternative Waveforms•Alternative Modulation Schemes• “High-Speed” Data Channel

Got eLoran?

LF APNTD Solutions

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Why eLoran (TerraNav)?

eLoran is NOT simply modernized Loran-C!

– requires a different timing strategy, control strategy, and new equipment to meet more stringent requirements

– specifies tighter timing tolerances

– transmissions are synchronized with respect to UTC (not SAM)

– employs a data channel for broadcast of application specific data

– includes Differential eLoran monitor stations and ASF maps to provide optimum accuracy in key areas (e.g. marine ports or airports)

Unaided Loran-C can never achieve the accuracy and integrity inherent in eLoran.

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

• Enhanced Loran• All the good stuff from Loran-C, plus:• New infrastructure & technology

• State-of-the-Art RF transmitters• Three cesium primary reference standards per station• Precision time & frequency equipment• Whole-station Uninterruptible Power Supply (UPS)• Robust telecommunications• UTC Synchronization techniques

• Cs or Rb Primary Reference Standard•TWSTT; TWLFTT; GNSS/RNSS

• GNSS/RNSS monitoring• NOT directly coupled or controlled

What is eLoran?

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

•New operational concepts• Time-of-transmission control• Differential corrections where applicable• All-in-view signals• ASF mapping• Data messaging channel(s)

• Loran Data Channel (9th pulse; 10th pulse; Eurofix; other)• Additional integrity• Differential corrections (dLoran and/or DGPS)• Other communication / navigation messages• “ComNav” solution possible

What is eLoran (continued)?

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

• New user equipment• Combination eLoran/GNSS receivers• Latest digital technology & small form factor• E-field antenna• H-field antenna (eliminates “p-static”)• Can use Chip-Scale Atomic Clocks for Direct Ranging Loran (DRL)

• Seamless across multiple modes (similar to GNSS)• Aviation; maritime; land mobile; location based; time & frequency

• Autonomous; interoperable; diverse; resilient

What is eLoran (continued)?

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

• Military operations (triple canopy, jamming situations, mountainous regions)

• Wide-area or localized timing source (+/- 30 ns of UTC)

• Critical infrastructure protection (ports, harbors, airports, key assets)

• High-profile events (Olympics)

• Interference-enabled crime fighting (car theft, border crossings, “toll” cheating, tracking felons)

• Heading / Pointing (Compass)

• Automatic Vehicle Location (AVL) services

• Submarine communications and navigation

• UAV / UAS solutions

• Irregular Warfare / Counterinsurgency (COIN) Operations

LF APNT&D (Loran, eLoran, TerraNav, LFPhoenix™) Uses

EMEA Operations

Bertem, Belgium




Leesburg, Virginia



– eLoran System








EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Representative Loran-C or eLoran System

System Level

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

System Level Considerations

• Required coverage accuracy and signal strength• Re-use existing stations?• Number and location of new stations• Complete EEZ coverage?• Single or dual rate?• GRI selection(s)• Transmitter and antenna sizing

• Sovereign or shared integrity control?

• Number and location of Monitor and dLoran Sites

• Level of ASF surveying required (ports, harbors, airports)

• GAARDIAN IDM capability?

• DGPS capability?

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Representative Transmitting Site Equipment

Transmit Site

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Transmit Site Considerations

• Collocate Control Center, Monitor Site, GAARDIAN IDM?

• Modulation scheme(s):

• 9th or 10th pulse

• Eurofix

• Prime power

• Commercial

• Generator

• Whole “station” UPS?

• Multilevel telecommunications?

• Landline, satellite, cellular, RF, LF

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Representative Control Center

“Control” Site

Note: System integrity control – monitors and takes OOT station off-air

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Monitor and/or dLoran Site

Monitor Site: collects signals and providesIntegrity information to Control Site

dLoran Site: special class of Monitor Siteproviding localized eLoran corrections oversurveyed-only solution for ports, harbors, airports, or other key areas. Similar to DGPS.

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

GAARDIIAN IDM

GAARDIAN: GNSS Availability, Accuracy, Reliability anDIntegrity Assessment for Timing and Navigation

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Representative dLoran Sites

• Chinhae

• Inchon

• Kunsan

• Masan

• Mokpo

• Pohang

• Pusan

• Tonghaehang

• Ulsan

• Yosu

• ICN

• GMP

• CJJ

• TAE

• KWJ

• CJU

• MMX

• PUS

• YNYNote: also good locations for GAARDIAN IDM interference monitoring and reporting.

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Two-Way Time Transfer Techniques

Two-Way Low Frequency Time Transfer (TWLFTT)

Two-Way Satellite Time Transfer (TWSTT)

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Transmit Site Representative Requirements

Meets or exceeds existing Loran-C and eLoran

transmitted signal specificationsimproves accuracy, availability, continuity, and integrity

Small size, weight, and input power requirementreduces facility size and transportation and installation

costs

High input power to transmitted power efficiencyreduces input power, HVAC, and generator costs; smaller

UPS

Instantaneous or near instantaneous module or system

switches with no appreciable degradation in transmitted

signal parameters

improves accuracy, availability, continuity, and integrity

No appreciable degradation in transmitted signal

parameters with a failure of signal generation or high-

power power amplification portions of the transmitter

improves accuracy, availability, continuity, and integrity

Minimum to no PM (other than air filter replacement) improves availability, continuity

Highest signal stability (phase stability, jitter, zero-

crossing, droop, etc.)improves accuracy

True hot-swappable modules improves availability, continuity

Local and remote system- and component-level visibility

through modern IP-based technology

goes to personnel reductions and ability to remotely

troubleshoot equipment/system

Capable of advanced signal generation and modulation

techniques, such as 9th pulse, 10th pulse, Eurofix, BPSK-

RC, OFDM, SIM

future-proofing

Capable of 700+ PPS future-proofing

Comprehensive 10-year warrantyreduces total cost of ownership (TCO) over the lifecycle

of the equipment

TRANSMITTER

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Transmit Site Representative Requirements

Precision Timing & Frequency Equipment (TFE), capable

of providing +/- 30 ns to UTC (+/- 10 ns with TWSTT)improves accuracy

TFE can use and ensemble Cs, Rb, GNSS, RNSS, or TWTT

inputsimproves accuracy, integrity

Multimode receivers capable of monitoring Loran-C,

eLoransingle receiver reduces TCO and logistics tail

Ability to modulate 9th pulse, 10th pulse, Eurofix, other future-proofing

TIMING, CONTROL, MONITORING, MODULATION

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Monitor Site and User Representative Requirements

MONITOR SITE

Multimode receivers capable of: - monitoring Loran-C and

eLoran (TerraNav);

- providing dLoran and eLoran calculations;

- providing DGPS positioning and horizontal accuracy

protection;

- providing ASF calculations;

- providing TWLFTT interface;

- providing UTC and Time-of-Day monitoring;

- providing frequency and 1 PPS output.

Ability to demodulate 9th pulse, 10th pulse, and Eurofix.

Capable of upgrading to monitor alternative waveforms

and modulation techniques.

Ability to use E-field, H-field, or combinations of

antennae.

USER

Multipurpose receivers capable of receiving Loran-C and

eLoran (TerraNav); ability to receive LDC messages (9th,

10th, Eurofix); ability to use E-field, H-field, or

combinations of antennae.

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Representative Solution Example: Transmitter

Nautel NL 40 100 kW ERPeLoran Transmitter

50 kW NL 20

• 21st century robust LF transmitter

• Powerful hot-swappable power amplifiers

• Very high efficiency

• Very small footprint

• Advanced User Interface

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Representative Solution Example: Transmitter

Modular Design Allows for Future Growth

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Representative Timing & Control Equipment

Time & Frequency Equipment

Cesium Beam Primary Reference Standard

LORSTA & Monitor Site monitor and control Receiver

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

• UrsaNav recently acquired all Intellectual Property rights of Locus Inc., Crossrate LLC, and Plutargus – Combining IP to provide the best solutions for our customers

• UN-150 eLoran timing receiver is the first to meet the stringent ETSI requirements for telecommunications Primary Reference Clocks

• First and only receiver to maintain smooth timing through failures of individual LORSTAs

UrsaNav UN-150 eLoran Timing Receiver

Representative Receiving Equipment

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

• eLoran and GPS timing receivers both meet the ETSI Primary Reference Clock mask

• Both receivers show equivalent performance

ETSI PRC mask

UN-150 eLoran timing receiver

Gold standard GPS timing receiver

eLoran Timing Receiver Performance

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Latest Receiver Technology

2.3125” X 0.875”

1.0625” X 0.75”

We are currently working with a partner to develop a verysmall footprint combination eLoran/GPS receiver with a VERY smallH-Field antenna (approximately 1.5 x 1.5 inches).

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Pohang 150 kW

Kwang Ju 50 kW

Niijima 800 kW

Gesashi 800 kW

Existing Sites Signal Strength Coverage

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Pohang 150 kW

Kwang Ju 50 kW

Niijima 800 kW

Gesashi 800 kW

Existing Sites Accuracy Coverage

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

New Sites Signal Strength Coverage

Pohang 150 kW

Kwang Ju 50 kW

Cheju-do 50 kW

Ullung-do 50 kW

Socheong-do 50 kW

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

New Sites Accuracy Coverage - Accufix

Pohang 150 kW

Kwang Ju 50 kW

Cheju-do 50 kW

Ullung-do 50 kW

Socheong-do 50 kW

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

New Sites Accuracy Coverage - NL

Pohang 150 kW

Kwang Ju 50 kW

Cheju-do 50 kW

Ullung-do 50 kW

Socheong-do 50 kW

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Pohang 150 kW

Kwang Ju 50 kW

Cheju-do 50 kW

Ullung-do 50 kW

Socheong-do 50 kW

Guleob-do 50 kW

New Sites Signal Strength Coverage

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

New Sites Accuracy Coverage - Accufix

Pohang 150 kW

Kwang Ju 50 kW

Cheju-do 50 kW

Ullung-do 50 kW

Socheong-do 50 kW

Guleob-do 50 kW

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

New Sites Accuracy Coverage - NL

Pohang 150 kW

Kwang Ju 50 kW

Cheju-do 50 kW

Ullung-do 50 kW

Socheong-do 50 kW

Guleob-do 50 kW

EMEA Operations

Bertem, Belgium




Leesburg, Virginia



– eLoran System








EMEA Operations

Bertem, Belgium




Leesburg, Virginia

REQUIREMENTS

Frequency: 100kHz

Design Operating Range: 25 nautical miles (46 km) radius

Field Strength: +55 dB/uv/m (1124 uv/m peak) at ground level

Location: Worldwide

Soil Type: Conductivity 1 mS/m; Permittivity 15

Minimal physical size, suitable for rapid deployment, tactical, temporary, or transportable requirements.

A radiated power level of 10 watts (40 watts peak) is necessary to achieve this range.

Soil type has a significant effect on antenna ground loss but minimal effect on propagation.

Top loading is typically used with electrically short antennas to optimize effective height and efficiency.

Peak antenna voltage is the limiting factor in these applications.

Small Footprint Solutions

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Representative Small Footprint Antennae

75-Foot Whip

“Tee”

60x60x60 Inverted Cone 90x90x90 Inverted Cone(Used for Field Test)

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Representative Small Footprint Antennae

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Small Footprint Solutions: Field Test Results

EMEA Operations

Bertem, Belgium




Leesburg, Virginia


Prototype Transmitter

AntennaFeedPoint

ViewInsideTruck

EMEA Operations

Bertem, Belgium




Leesburg, Virginia


EMEA Operations

Bertem, Belgium




Leesburg, Virginia


Equipment Truck

Telescoping Antenna Supports

Antenna Tuning Unit

EMEA Operations

Bertem, Belgium




Leesburg, Virginia


90x90x90 Inverted Cone Antenna

EMEA Operations

Bertem, Belgium




Leesburg, Virginia


EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Spotlight on Jamming

Jammer 10 km inside N. Korea – Radius of 50 km

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Spotlight on Jamming

10 W ERP Tactical eLoran System – 25 NM radius around Seoul

EMEA Operations

Bertem, Belgium




Leesburg, Virginia



– eLoran System








EMEA Operations

Bertem, Belgium




Leesburg, Virginia 51

• Improved phase codes – Phase codes should average to zero – Pseudo-Random Noise (PRN) based phase codes will allow unique identification of a station in a

group and will reduce cross-correlation of signals from other stations

• Waveforms can be improvedover traditional Loran-C.

• Examples of actual on-airtransmitted waveforms areshown here.

• Shorter pulses allow for morenavigation pulse, or room formore data. Navigation functionis not degraded.

• Improve crossrate effects.

• 700 PPS successfully tested.

• All tests performed on a625’ TLM using a NautelNL 20 prototype transmitter.

Alternative Waveforms

EMEA Operations

Bertem, Belgium





• Navigation with low-bitrate comms. eLoran has proven performance. • Separate high-bitrate comms channel (1500 bps or more)• Nav and comms possibly transmitted from single antenna• Receiver: single box, single antenna• LFPhoenix™

Alternative Signals

EMEA Operations

Bertem, Belgium





• Navigation with high-speed comms (1500 bps or more)

• Uses same spectrum as Loran-C / eLoran

Alternative Signals

EMEA Operations

Bertem, Belgium





• f1: Long-range navigation with comms (1500 bps)• f2: Short-range navigation with comms (>1500 bps)• Nav and comms possibly transmitted from single antenna• Receiver: single box, single antenna

Alternative Signals

EMEA Operations

Bertem, Belgium





• Current LF communications are typically below 100 bps

• Dedicating a time slice to communications allows advanced techniques

• Orthogonal Frequency Division Multiple Access (OFDMA)

– Allows very efficient time/bandwidth use

– High data throughput (>1500 bps usable)

– Robust against impulsive noise

– Multiple transmitters operating at the same time with no interference

– Little to no increase in power outside of the 90-110 kHz band, depending on transmitter linearity

Alternative Modulation: OFDM

EMEA Operations

Bertem, Belgium





• Large number of orthogonal carriers

• Typically uses amplitude and phase modulation on each carrier (QAM)

• Used in modern communications systems due to bandwidth efficiency

• Longer symbol times decrease bandwidth requirements and increase robustness

• Use of pilot carriers enhances synchronization and allows the channel to be equalized


EMEA Operations

Bertem, Belgium





• 805 carriers total

• 161 carriers per site

• 78 16 QAM carrier

• 78 QPSK carriers

• 5 BPSK pilot carriers

• 473 bits/symbol

• 2838 bps (uncoded)

• Coding rate of 2/3 could achieve 1892 bps per transmitter

• Resultant signal has similar bandwidth requirements to the navigation pulse, allowing one transmitter for both signals


EMEA Operations

Bertem, Belgium





• Noise-like signal, rather than pulsed

• Signal peaks similar to navigation pulses

• Long symbol time allows noise to be averaged

Navigation pulses

Communication symbols (130 ms)


EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Additional Information and Contacts

“Alternatives to the Sky – eLoran” White Paper.

“Pioneering New Frontiers in Position, Navigation, and Timing“ White Paper.

Low-Frequency (LF) Solutions for Alternative Positioning, Navigation, Timing, and Data (APNT&D) and Associated Receiver Technology” paper and presentation.

Nautel Brochure.

Symmetricom Brochure.

“An Evaluation of the Effectiveness of Intentional Interference to eLoran” – MITRE.

EMEA Operations

Bertem, Belgium




Leesburg, Virginia

Questions?

Transmission and User Requirements Technology for eLoran ...

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