1、BRITISH STANDARD BS EN 61075:1993 Incorporating Amendment No.1 Loran-C receivers for ships Minimum performance standards Methods of testing and required test results The European Standard EN61075:1993 has the status of a BritishStandard UDC621.396.62:629.12:620.1:621.317.08BSEN61075:1993 This Britis
2、hStandard, having been prepared under the directionof the Electronic Equipment Standards Policy Committee, was published underthe authority of the Standards Board and comes intoeffect on 29 November1991 BSI12-1999 The following BSI references relate to the work on this standard: Committee reference
3、EEL/30 Draft for comment90/22751DC ISBN 0 580 20280 1 Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted by the Electronic Equipment Standards Policy Committee (EEL/-) to Technical Committee EEL/30, upon which the following bodies were represented:
4、British Marine Electronics Association British Marine Equipment Council British Motor Ship Owners Association British Nautical Instrument Trade Association Civil Aviation Authority Department of Transport (Marine Directorate) EEA (the Association of Electronics, Telecommunications and Business Equip
5、ment Industries) General Council of British Shipping Lloyds Register of Shipping Marine Trades Association Ministry of Defence National Union of Seamen Nautical Institute Radiocommunications Agency Amendments issued since publication Amd. No. Date Comments 7886 August 1993 Indicated by a sideline in
6、 the marginBSEN61075:1993 BSI 12-1999 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN61075 3 Publication(s) referred to Inside back coverBSEN61075:1993 ii BSI 12-1999 National foreword This BritishStandard has been prepared under the direction of
7、the Electronic Equipment Standards Policy Committee. It is identical with IEC1075:1991 “Loran-C receivers for ships. Minimum performance standards Methods of testing and required test results” published by the International Electrotechnical Commission (IEC). In1993 the European Committee for Electro
8、technical Standardization (CENELEC) accepted IEC1075:1991 (modified) as European Standard EN61075:1993. As a consequence of implementing the European Standard this BritishStandard is renumbered as BS EN61075 and any reference to BS7538 should be read as a reference to BS EN61075. Copies of CCIR docu
9、ments may be purchased from: BSI Sales Linford Wood Milton Keynes MK146LE Copies of US Coastguard documents may be purchased from: US Coastguard G-MVI 2100 Second Street SW Washington DC USA A British Standard does not purport to include all the necessary provisions of a contract. Users of British S
10、tandards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International Standard Corresponding BritishStandard IEC945:1988 BS7169:1989 Specification for general requirements for marine naviga
11、tional equipment (Identical) IEC1023:1990 BS7408:1991 Specification for marine speed and distance measuring equipment (SDME) (Identical) Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to12, an inside back cover and a back cover.
12、This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN61075 April1993 UDC621.396.62:629.12:620.1:621.317.08 Descriptors: Ship, navigatio
13、nal instrument, Loran-C receiver, performance requirement, operational requirement, method of testing, required test result English version Loran-C receivers for ships Minimum performance standards Methods of testing and required test results (IEC1075:1991) Rcepteurs Loran-C pour navires Exigencesmi
14、nimales de fonctionnement Mthodes dessai et rsultats exigibles (CEI1075:1991) Loran-C Empfnger fr Schiffe Mindestleistungsanforderungen Prfverfahren und geforderte Prfergebnisse (IEC1075:1991) This European Standard was approved by CENELEC on1993-03-09. CENELEC members are bound to comply with the C
15、EN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or t
16、o any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official
17、 versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CENELEC European Committee for Electrotechnical St
18、andardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1993 Copyright reserved to CENELEC members Ref.No.EN61075:1993EEN61075:1993 BSI 12-1999 2 Foreword The CENELEC questionnaire procedu
19、re, performed for finding out whether or not the International Standard IEC1075:1991 could be accepted without textual changes, has shown that no common modifications were necessary for the acceptance as a European Standard. The reference document, together with CENELEC common modifications, was sub
20、mitted to the CENELEC members for formal vote. The text of the draft was approved by CENELEC as EN61075 on9 March1993. The following dates were fixed: For products which have complied with the relevant national standard before1994-03-01, as shown by the manufacturer or by a certification body, this
21、previous standard may continue to apply for production until1999-03-01. Annexes designated “normative” are part of the body of the standard. In this standard, Annex A, Annex B, Annex C, Annex D and Annex ZA are normative. Contents Page Foreword 2 1 Scope 3 2 Normative references 3 3 Minimum performa
22、nce standards 3 3.1 Introduction 3 3.2 General 4 3.3 Receiving conditions of the radio signals 4 3.4 Processing 5 3.5 Display 5 3.6 Warnings 6 3.7 Ancillary equipment 6 4 Methods of testing and required test results 6 4.1 General 6 4.2 Tests and required results 6 Annex A (normative) Definitions and
23、 additionalinformation 9 Annex B (normative) Sky-wave 11 Annex C (normative) Time difference to latitudeandlongitude. Procedure for conversionaccuracy simulator check 11 Annex D (normative) List of abbreviations 12 Annex ZA (normative) Other international publications quoted in this standard with th
24、ereferences of the relevant European publications 12 Figure 1 Testing installation 7 Table 1 Radio signal receiving and processingtests 8 latest date of publication of an identical national standard (dop) 1994-03-01 latest date of withdrawal of conflicting national standards (dow) 1994-03-01EN61075:
25、1993 BSI 12-1999 3 1 Scope This International Standard specifies the minimum performance standards and type testing of shipborne receivers for Loran-C systems and is associated with IEC945 and IEC1023. The objective of the standard is to establish minimum performance standards, methods of testing an
26、d required test results for Loran-C general purpose shipborne navigational receivers. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were
27、 valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to Investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid Internationa
28、l Standards. IEC945:1988, Marine navigational equipment General requirements Methods of testing and required test results. IEC1023:1990, Marine speed and distance measuring equipment (SDME) Operational and performance requirements Methods of testing and required test results. CCIR Recommendation589-
29、1:1986, Interference to radionavigation services from other services in the bands between70kHz and130kHz. CCIR Report915-1:1986, Interference between fixed, maritime mobile and radionavigation services in the bands between70kHz and130kHz. US Coastguard COMDTINST M16562.4:1981, Specification of the t
30、ransmitted Loran-C signal. 3 Minimum performance standards 3.1 Introduction The characteristics defined in this International Standard are the minimum for Loran-C receivers intended to be used on board merchant ships, the speed of which does not exceed35knots. 3.1.1 Loran-C system Loran-C is a long
31、range radionavigation system, operating at an assigned frequency of100kHz, utilising pulses from spaced transmitting stations, in which lines of position are determined by the measurement of the differences in the time of arrival of these pulses. 3.1.2 International agreement There is no formal inte
32、rnational agreement for the Loran-C system, but transmitted signals follow the US Coastguard specification of the transmitted Loran-C signal (US Coastguard COMDTINSTM16562.4:1981). 3.1.3 Receiver types 3.1.3.1 The term “Loran-C receiver” used in this standard refers to a receiving equipment which in
33、cludes an antenna coupler, a signal processor,etc.,and applies only to receivers manufactured for marine navigational use at sea. 3.1.3.2 The main functions of Loran-C receivers are: a) initial selection of the group repetition interval (GRI) and acquisition of the Master and at least two secondary
34、groups of phase coded pulses; b) settling a sampling process for each of the above signal groups on a similar cycle zero-crossing in order to provide ground-wave tracking uncontaminated by sky-wave signals. This can never occur on the third cycle as the signals are delayed and distorted by the signa
35、l filtering circuits, and it is normal practice to track a few microseconds ahead of the third cycle crossing. Sky-wave reception delay relative to the ground-wave is always in excess of304s; c) measurements of time differences, calculation and display of the current position estimate. 3.1.3.3 A Lor
36、an-C marine receiver should have the capability of fully automatic acquisition, cycle selection and track. After the initial selection, the receiver automatically acquires the Master and at least two secondaries, settles, selects the cycle, tracks the signals and periodically updates the time differ
37、ences and geographical coordinates. The receiver should allow (but not require) operator assistance to acquire the secondaries (semi-automatic acquisition). 3.1.3.4 Loran-C receivers should allow the operator to select either time differences or geographical coordinates (or both) for presentation on
38、 the display. The geographical coordinates should be obtained by automatic conversion of the measured time differences. 3.1.3.5 Loran-C receivers may be provided with: a) an input allowing the manual introduction of corrections or current known position; b) one or several outputs allowing the operat
39、ion of associated plotters or integrated navigation systems; c) a device automatically introducing corrections in a given area.EN61075:1993 4 BSI 12-1999 3.1.3.6 This standard does not apply to marine receiver types which use the range-range mode of positioning from the Loran-C system. 3.2 General 3
40、.2.1 General requirements Loran-C receivers shall comply with the conditions of IEC945. Additional requirements to that standard are given in3.2.2, 3.2.3 and3.2.4. 3.2.2 Power supply The receivers shall be able to be supplied by at least one of the usual sources found on board ships, i.e.: a) altern
41、ating current:100/110/115/120/220/230V; b) direct current:12/24/32V. 3.2.3 Starting up The receivers shall be able to operate and comply with this standard15min after switching on. 3.2.4 Safety 3.2.4.1 Precautions shall be taken to ensure that no damage can result from an accidental short circuit or
42、 grounding of the antenna input or any of the inputs or outputs for a duration of5min. 3.2.4.2 Precautions shall be taken to avoid as far as possible damage to receivers from transient overvoltages on the antenna or receiver inputs (e.g.those resulting from other equipments using the same power supp
43、ly or from lightning). 3.2.4.3 Precautions shall be taken to ensure that isolation exists between the power supply input and receiver ground and that inadvertent reversal of polarity of the power supply causes no damage to equipment. 3.3 Receiving conditions of the radio signals 3.3.1 Accuracy The p
44、rocessing shall be such that the combined accuracy (RSS of mean and standard deviation of the time-difference error) is less than0,34s. (Acomplete definition of this combined accuracy is given in Annex A.) The range of reference signals that shall be complied with are the following: a) signal level:
45、17,84V/m to316mV/m(25dB to110 dB/14V/m); b) differential signal level:0dB to60dB; c) envelope to cycle difference (ECD): 2,44s; d) signal-to-noise ratio: minimum shall be0dB in a noise level range of44V/m to5,6mV/m(12dB to75dB/14V/m) (seedefinition inAnnex A). NOTEThe Loran-C coverage area diagrams
46、published by the United States Coastguard refer to a receiver operating with a signal-to-noise ratio of10dB. A receiver complying with this minimum standard (SNR of0dB) will therefore operate in a correspondingly reduced coverage area. Under time of emission (TOE) control of Loran-C Master stations
47、it can be expected that the contribution to combined accuracy from chain timing will be considerably improved. 3.3.2 Interference protection 3.3.2.1 Synchronous and near synchronous interference(seedefinitions inAnnex A) Interference may occur when signals are synchronous or near synchronous with an
48、y spectral line of the Loran-C sampling rate. Near synchronous implies that the difference in frequency between the interfering carrier (or sub-carrier) and the nearest spectral line is within the bandwidth of any post sampling averaging or filtering process. Loran-C receivers suffer mostly from int
49、erfering signals transmitted outside the allocated band i.e.70kHz90kHz and110kHz130kHz, although there are significant sources of interference within the allocated band of90kHz110kHz(seealso Radio Regulation451-MOB-87). This subject is discussed in detail in CCIR Report915-1 (MOD F) and CCIR Recommendation589-1 and includes protection ratios for Loran-C systems. The receivers shall meet the requirements of this standard with a minimum of two near synchronous near-band sources of interference of0dB signal-to-interference ratio (SIR) pr
