Arthur Helwig, ILA 32, November 4-7, Boulder, CO 1 reelektronika

Reelektronika’s IntegratedLoran-C/GPS/Eurofix receiver

- early test results

Dr. Arthur Helwig

Reelektronika, Netherlands

ILA 2003Boulder, Colorado, USA, 3-7 November 2003

Dr.ir.

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PhD Arthur & Gerard, 13 Oct 2003

Thank you!

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Marine trials

• Trials to assess an integrated GPS/Eurofix receiver

• Out of the Eckernförde harbor, using a small (30 ft) vessel

• Two trial runs:– 10/12 June 2003– 9/10 Oct 2003

• Third trial scheduled for January 2004

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Measurement vessel

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Measurement set-up• “Old version” Loradd receiver

Performs:- Bandpass filtering- Cross-rate filtering

Outputs:- Eurofix datalink information- Cleaned up pulses for every tracked Loran-C station

• PC running MatlabPerforms:

- ECD measurement- Cycle identification- Range calculation, using ASF and/or GPS calibration

Outputs:- Positions calculated in a number of modes

• NovAtel OEM4 GPS receiver• Laptop for display of data

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Picture of set-up

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Map of test area

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NELS 100m coverage (95%)

Tests were performed at boundary of NELS coverage

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Modes of position calculation

1. DGPS, SPS Radiobeacon mode

2. DPGS, SPS Eurofix mode

3. GPS, SPS mode

4. Loran-C, DGPS calibrated mode

5. Loran-C, ASF-table calibrated mode

6. Loran-C, stand-alone mode

7. Fix not available• Simultaneous output of selected modes• Automatic mode

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Station availability

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Tracked Loran-C stations

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Modes of operation

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Track plots

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Sailing under a powerline

• Powerline approx. 75 meters high

• High voltage• No noticeable influence

on receiver performance

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Early conclusions• Operational fully automatic receiver

– GPS– Autonomous Loran-C– ASF-corrected Loran-C– GPS-calibrated Loran-C

• Even under sub-optimal conditions, first track results look promising

• Work to be done:– Implement advanced RF interference mitigation (on-

ship power generator was suspect)– Implement of H-field antenna compensation– Check cycle ID / ECD measurement algorithms– Automatic station selection (to be used in position

calculation algorithm)

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Tasks at handSignal Processor

77 x 51 mmWhen we…

• Finalise tracking & positioning code

• Port all software code to DSP board

• Finish antenna production

… we’ll have a functional small receiver in Q1 2004

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Monitor set-up at      

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Demonstration