Loran c Enav

NAVIGATION

Loran C

LORAN-C is a

hyperbolic

navigation system.

Operates by measuring

time distance of arrival

of signals from a pair of

synchronised

transmitters.

By using two pairs

of transmitters a

fix can be obtained.

Transmitter 1

LOPs

ExtendedBaseline

Transmitter 2

A navigation system that was developed by the

US Coast Guard.

The system is comprised of transmission

stations located around the world.

The Loran-C signal is transmitted from these

stations at specified intervals.

By measuring the time delay between

transmissions a user can determine their

position relative to the towers.

The LORAN-C concept is based on groups or

“chains” of stations around the world.

Worldwide there are 28 chains.

Each chain consists of one master station and

4 – 6 secondary stations in a geographic area

The master station of each chain broadcasts a

continuous string of Low Frequency pulses

(measures in microseconds).

The unique time between the start and stop of

each pulse identifies the particular chain.

DIAGRAM 1.1

A and B - transmitting

stations

Curved lines- “TD” lines or

Time Difference

DIAGRAM 1.2

100kHz centre frequency

99% of power within 90-110kHz…

Loran C Timing

Up to three commercial cesium atomic clocks are

used to generate 5 MHz and pulse per second (or

1 Hz) signals that are used by timing equipment to

generate the various GRI-dependent drive signals

for the transmitting equipment.

Cesium Atomic Clocks

where a minus sign indicates an inverted pulse (180°phase shift)

and a plus sign means no phase shift.

This pattern is repeated every two GRI's.

Simply stated,phase coding determines whether the first peak in the pulse is upwardsor downwards.

Phase Coding

0

Timings from 3rd zero-crossing (30 S)

50 100 150 200

Loran C Pulses

Unlike GPS, LORAN-C accuracy depends on

receiver location with respect to transmitters

Best on baseline between master and slave

because LOPs are closer here

LORAN accuracy is also best over water during

the day.

Conversely it is least accurate over land

masses at night (sky waves more intense at

night).

Types of Accuracy:

Repeatable Accuracy- ability to return to a pre-set position for LORAN-C is .01 NM or 60ft.

Absolute Accuracy- ability of the receiver to determine its position independently is generally within at least 3 NM for distances up to 2,800 NM.

Chayka was developed by USSR (Russia)

Similar to LORAN-C

Same frequency but different pulse shape

Russian Chayka chains also remain

operational

West Russia chain available in Eastern Europe

Some Loran-C receivers also use

Chayka signals

Transmitter Designation

Emission Delay (µS)

Location Country Coordinates

Power (kW)

Latitude Longitude

Lessay 6731 Chain

M Lessay France 49°08′55.224″N 01°30′17.029″W 250

X 13,000 Soustons France 43°44′23.099″N 01°22′49.584″W 250

Y 27,300 Anthorn UK 54°54′41.949″N 03°16′42.587″W 250

Z 42,100 Sylt Germany 54°48′29.975″N 08°17′36.856″E 250

Bø 7001 Chain

M Bø Norway 68°38′06.216″N 14°27′47.350″E 400

X 14,100 Jan Mayen Norway 70°54′51.478″N 08°43′56.525″W 250

Y 29,100 Berlevåg Norway 70°50′43.014″N 29°12′15.980″E 250

Eiði 9007 Chain

M Eiði Faroe 62°17′59.837″N 07°04′26.079″W 400

W 14,200 Jan Mayen Norway 70°54′51.478″N 08°43′56.525″W 250

X 28,000 Bø Norway 68°38′06.216″N 14°27′47.350″E 400

Y 41,100 Værlandet Norway 61°17′49.435″N 04°41′46.618″E 250

Sylt 7499 Chain

M Sylt Germany 54°48′29.975″N 08°17′36.856″E 250

X 14,100 Lessay France 49°08′55.224″N 01°30′17.029″W 250

Y 29,500 Værlandet Norway 68°38′06.216″N 14°27′47.350″E 250

Former NELS & Chayka Chains

Rugby

Jan Mayen

Lessay

Soustons

Berlevåg

Simferopol

SlonimKarachev

Petrozavodsk

Bø

VærlandetEi ið

Sylt

MARTHA’S VINEYARD

41 20N – 70 49W

1957 - 1962

Y

CAROLINA BEACH

1957 - Present

34 03 46.36N

77 54 46.19WM

JUPITER INLET

1957 - Present

27 01 59.09N

80 06 52.92W

Station relocated approx 2 miles

north 1962

X

S-0/1957 – 1962

SL-0/1962 - 1965

Y

NANTUCKET

1962 - Present

41 15 11.93N

69 58 38.76W

Replaced Martha’s Vineyard

First Proven Loran System

Status “Experimental” until 1962

“Operational” 1962

CHAIN CODE NAME: CLOSE

SS0/1966 – 1969

SS7/1969 – 1975

9930/1975 – 1978

YX

W

JUPITER INLET

1957 – Present

27 01 58.490N

80 06 53.520W

CAROLINA BEACH

1957 – Present

34 03 46.040N

77 54 46.760W

NANTUCKET

1962 – Present

41 15 11.930N

69 58 39.090W

M

CAPE RACE

1966 – Present

46 46 32.180N

53 10 28.160W

NOTE:

WILDWOOD used as temp

Master or Slave “T”

CARIBOU USED as Slave S

Z

DANA

1967 – Present

39 51 07.540N

87 29 12.140W

BERMUDA

32 15 53.261N

64 52 34.270W

EGLIN

30 35 05.518N

86 36 54.470W

7930-Z

SENECA

1978 – Present

42 42 50.603N

76 49 33.862W

9960/1978 - PresentCARIBOU

1978 – Present

46 48 27.199N

67 55 37.713W

M

W

X

NANTUCKET

1962 – Present

41 15 11.930N

69 58 39.090W

CAROLINA BEACH

1957 – Present

34 03 46.040N

77 54 46.760W

YDANA

1966 – Present

39 51 07.540N

87 29 12.140W

Z

PLUMBROOK

41 21 45N

82 38 52W

CAPE ELIZABETH

43 34N – 70 12W

SANDY HOOK

40 28 17N

74 01 05W

MAYPORT

30 22 58.253N

81 25 13.314W

5930-X

5930-M

7980-Z

8970-M 8970-X

5930/1980 - PRESENT

NANTUCKET

41 15 11.93N

69 58 39.09W

1980 - PRESENT

CARIBOU

46 48 27.199N

67 55 37.713W

1980 - PRESENT

CAPE RACE

46 46 32.18N

53 10 28.16

1980 - PRESENT

FOX HARBOR

1984 - PRESENTZ

Y

M

X

7930-W

9960-W

7930-M

9960-X

FOX HARBOR

52 22 35.252N

55 42 27.862W

7930/1984 - 1994

CAPE RACE

46 46 32.286N

53 10 27.606W

ANGISSOQ

59 59 17.27N

45 10 27.47W

X

M

W

7930-Z

5930-Y

7270/1995 - Present

COMFORT COVE

49 19 53.57N

54 51 42.57W

CAPE RACE

46 46 32.286N

53 10 27.606W

FOX HARBOR

52 22 35.252N

55 42 27.862W

M

X

W

5930-Y

5930-Z

SL-6/1959 – 1964

SL-0/1964 – 1966

SL-3/1966 – 1975

7970/ 1975 - 1994

Chain Code Name: RAIL

X

BO, NORWAY

1959 – 1994

68 38 06.150N

14 27 47.000E

M

EJDE, FAEROES

1959 – 1994

62 17 59.680N – 07 04

26.710W

SANDUR, ICELAND

1959 – 1994

64 54 26.580N – 23 55 21.750W

Y

JAN MAYEN

1959 - 1994

70 54 52.610N

08 43 58.690W

SYLT, GERMANY

1964 – 1994

54 48 29.800N – 08 17 36.330E

W

Z

SHETLAND

60 26 25.347N

01 18 05.220W

SL-7-W

7930-W

9980-M

SL-7-X (1996-75)

7930-X (1975-83)

9980-X (1984-94)

ON AIR Mar 1960

SL-6

29 Mar 1962 –

Ejde tower collapased

Chain Code Name: RAIL

X

BO, NORWAY

1959 – 1994

68 38 06.150N

14 27 47.000E

Y

JAN MAYEN

1959 - 1994

70 54 52.610N

08 43 58.690W

M

ON AIR Mar 1960

SANDUR, ICELAND

1959 – 1994

64 54 26.580N – 23 55 21.750W

M

SL-7/1966 – 1975

7930/1975 - 1983

ANGISSOQ

1966 – 1983

59 59 17.270N

45 10 27.470W

CAPE RACE

1966 –1983

46 46 32.180N

53 10 28.160W

Z

EJDE

1959 – 1983

62 17 59.680N

07 04 26.710W

X

SANDUR

1959 – 1983

64 54 26.580N

23 55 21.750W W

SL-3-M

7970-M

SL-3-Y

7970-Y

KEFLAVIK

63 57 26N

22 43 29WST ANTHONY

51 21 37N

55 37 28W

SS-0-X (1966-69)

SS-7-X (1969-75)

9980/1984 - 1994

SANDUR

64-54-26.58N

23-55-21.75W

EJDE

62-17-59.68N

07-04-26.71W

M

X

ANGISSOQ

59-59-17.27N

45-10-27,47W

W

7930-X

7970-M

ESTARTIT, SPAIN

Oct 1961 – Dec

1994

42 03 36.490N

03 12 15.900E

Z

MATRATIN, LIBYA

1959-1970

30 36N – 18 24E

SL-4/1959 –1966

SL-1/1967 – 1975

7990/1975 - 1994

LAMPEDUSA

AUG 1972 - DEC 1994

35 31 20.880N

12 31 29.960E

KARGABARUM, TURKEY

AKA: TUSLOG DET 52

AKA: TARGABARUM

1959 – 1993*

40 58 20.950N

27 52 01.520E

Chain Code Name: TACK

SELLIA MARINA, ITALY

AKA: SIMERI CRICHI

1959 – 1994

38 52 20.610N

16 43 05.960E

SL-4/X

SL1-7990/Y

M

SL-4/Y

SL-1/X

X

Construction started DEC 58…ON AIR AUG 59

RHODES

36 25

20.746N

28 09

31.920E

SARDINIA

39 10 51.348N

09 09 35.020E

8970/1980 - Present

DANA

1967 – Present

39 51 07.540N

87 29 12.140W

MALONE

1978 – Present

30 59 38.740N

85 10 09.305W

SENECA

1978 – Present

42 42 50.603N

76 49 33.862WBAUDETTE

1978 – Present*

48 36 49.947N

94 33 17.915W

M

W

X

Y

MUSKEGON

43 13N – 86 16W

MABLEHEAD

41 32N – 82 43W

ELGIN

30 35 05.518N

86 36 54.470W

MAYPORT

30 22 58.253N

81 25 13.314W

BOISE CITY

1980 - Present

Z

8290-W

9610-M

(1991)

9960-Z

7980-M

9960-M

M

8970-Y

BAUDETTE

48 36 49.947N

94 33 17.915WW

8290/1991-PRESENT

GILLETTE

44 00 11.305N

105 37 23.895W

X

9610-V

HAVRE

48 44 38.589N

109 58 53.613W

WILLIAMS LAKE

51 57 58.876N

122 22 01.686W

Y

5990-M

W

9610/1991 - PRESENT

8970-Z

BOISE CITY

36 30 20.783N

102 53 59.487W

GRANGEVILLE

30 43 33.018

90 49 43.600W

7980-WRAYMONDVILLE

26 31 55.006

97 50 00.093

7980-X

Z

Y

X

LAS CRUCES

32 04 18.130N

106 52 04.388W

W

SEARCHLIGHT

35 19 18.305N

114 48 16.881W

9940-YV

GILLETTE

44 00 11.305N

105 37 23.895W

8290-X

M

7980/1978 - Present

MALONE

1978 – Present

30 59 38.740N

85 10 09.305WGRANGEVILLE

1978 – Present

30 43 33.018N

90 49 43.600W

RAYMONDVILLE

1978 – Present

26 31 55.006

97 50 00.093

WM

X

JUPITER

1957 – Present

27 01 58.490N

80 06 53.520W

Y

CAROLINA BEACH

1957 – Present

34 03 46.040N

77 54 46.760W

MAYPORT

30 22 58.253N

81 25 13.314W

Z

EGLIN

30 35 05.518N

86 36 54.470W

SABINE PASS

29 40N –93 50W

9960-Y

9610-Z

8970-W

9610-Y

9940/1977 - Present

M

FALLON

1977 – Present

39 33 06.620N

118 49 56.370W

GEORGE

1977 – Present

47 03 47.990N

119 44 39.530WW

MIDDLETOWN

1977 – Present

38 46 56.990N

122 29 44.529W SEARCHLIGHT

1977 – Present

35 19 18.305N

114 48 16.881W

Y

X

PT PINOS

36 37 59.020N

121 56 05.580W

NORTH BEND

43 24 36.210N

124 14 27.920W

9610-W

5990-Y

GEORGE

1977 – PRESENT

47 03 47.990

119 44 39.530W

Y

5990/1977 - PRESENT

9940-W

PORT HARDY

50 36 29.830N

127 21 28.489W

Z

SHOAL COVE

55 26 20.940N

131 15 19.094W

X

M

WILLIAMS LAKE

51 57 58.876N

122 22 01.686W

7960-Y

8290-Y

JUNEAU

58 17 54.847N

134 24 45.369W

ALBERT BAY

50 35 10.0N

126 54 39.0W

NORTH BEND

43 24 36.210

124 14 27.920

M

TOK

1977 – Present

63 19 42.810N

142 48 31.900WNARROW CAPE

1977 – 1990

KODIAK

1990 - Present

57 26 20.210N

152 22 11.219W

9990-Z

X

7960/1977 - Present

SHOAL COVE

1977 – Present

55 26 20.850N

131 15 19.850

Y

5990-X

KODIAK Monitor

57 44 00.703N

152 30 20.356W

JUNEAU

58 17 54.847N

134 24 45.369

ST PAUL

1960 – Present

57 09 09.880N

170 14 59.810W

SL–2/1960 – 1969

SH-7/1969 – 1975

5930/1975 – 1977

9990/1977 - Present

M

ATTU

1960 – Present

52 49 45.050N

173 10 52.310W

SL-2/Y

SH-7/X

5930/X

9990/X

PORT CLARENCE

1961 –Present

65 14 40.120N

166 53 14.470W

SITKINAK

1960 –1977

56 32N – 154 08W

SL-2/Z

SH-7/Y

5930/Y

9990/Y 9990/Z

SL-2/X

SH-7/Z

5930/Z

NARROW CAPE

1977 – 1990

KODIAK

1990 - Present

57 26 20.210N

152 22 11.219W

7960-X

KODIAK Monitor

57 44 00.703N

152 30 20.356W

AKA: Bering Sea Chain early 60’s

SS-3/1964-1975

9970/1975-1981

7930/1981(IWO O/A)

9970/1981-1993

M

IWO JIMA

1964 – 1993

24 48 04.100N

141 19 28.999E

HOKKAIDO

1964 – 1993

42 44 37.000N

143 43 09.060E

7930 YANKEEX

MARCUS*

1964 – 1993

24 17 07.700N

153 58 51.500E

*Master when

Iwo off air

W

GESASHI

1964 –1993

26 36 24.990N

128 08 56.210E

7930 X-RAY

YAP

1964 – 1987

09 32 45.660N

138 09 55.230E

Y

ZBARRIGADA

1987 - 1993

Z

SAIPAN

15 07 47.115N

145 41 37.620W

KAMISEYA

35 29 11.555N

139 29 25.120E

Chain reconfigured Mar 64 – Dec 64 due to

Towers failure at Iwo and Yap. Again in 1981 for tower maintenance @ Iwo.

M

JOHNSTON ISLAND

1961 – 1992

16 44 43.950N

169 30 31.200W

SH-4/1961-1969

S-1/1969-1975

4990/1975-1992

UPOLA POINT

1961 – 1992

20 14 49.160N

155 53 09.700W

X

KURE ISLAND

1961 – 1992

28 23 41.770N

178 17 30.200W

YFRENCH FRIGATE

23 52 23.066N

166 17 19.600W

AKA: Hawaii Chain early 60’s

S3/1966 - 1969

SH-3/1969 - 1975

M

Y

X

CONSON

1966 – 1975

08 43N – 106 38E

LAMPANG

1966 – 1975

18 20N – 99 23E

SATTAHIP

1966 –1975

12 37N – 100 58E

Z

TAN MY

1969 – 1975

16 33N – 107 39E

UDORN

1966 – 1975

MONITOR