GEN 2  TABLES AND CODES

GEN 2.1  MEASURING SYSTEM, AIRCRAFT MARKINGS, HOLIDAYS

   GEN 2.1.1 UNITS OF MEASUREMENT

The following table of units of measurement will be used by aeronautical stations within the Riga FIR.

FOR MEASUREMENT OF

UNITS USED

Distance used in navigation, position reporting, etc. - generally in excess of 2 nautical miles

Nautical Miles and tenths

Relatively short distances such as those relating to aerodromes (e.g. runway lengths)

Metres

Altitudes, elevations and heights

Feet

Horizontal speed including wind speed

Knots

Vertical speed

Feet per minute

Wind direction for landing and taking off

Degrees Magnetic

Wind direction except for landing and taking off

Degrees True

Visibility including runway visual range

Kilometres or Metres

Altimeter setting

Hectopascal

Temperature

Degrees Celsius

Weight

Metric tons or Kilograms

Time

Hours and Minutes, a 24-hour day beginning at midnight UTC


   GEN 2.1.2 TEMPORAL REFERENCE SYSTEM

Co-ordinated Universal Time (UTC) is used by navigation services and in publications issued by the Aeronautical Information Service. Reporting of time is expressed to the nearest minute, e.g. 12:40:35 is reported as 1241.

In the AIP and associated publications, the expression “summer period“ indicates the part of the year in which the “daylight saving time“ is in force. The other part of the year will be named the “winter period“. Daylight saving time in Latvia is UTC plus 3 hours.

The “summer period“ will be introduced every year on the last Sunday in MAR at 0100 UTC and it will cease on the last Sunday in OCT at 0100 UTC.

Times applicable during the “summer period“ are given in brackets. Local time in Latvia is:

  • UTC plus 2 HR, during the winter period;
  • UTC plus 3 HR, during the summer period.

   GEN 2.1.3 HORIZONTAL REFERENCE SYSTEM

  1. Name/designation of the reference system

All published geographical co-ordinates indicating latitude and longitude are expressed in terms of the World Geodetic System - 1984 (WGS-84) geodetic reference datum.

  1. Identification and parameters of the projection

The projection is expressed in terms of Universal Transverse Mercator (UTM).

  1. Identification of ellipsoid used

The ellipsoid is expressed in terms of World Geodetic System -1984 (WGS-84) ellipsoid.

  1. Identification of the datum used

The World Geodetic System -1984 (WGS-84) is used.

  1. Area(s) of application

The area of application for the published geographical co-ordinates coincides with the area of responsibility of the Aeronautical Information Service, i.e. the entire territory of the Republic of Latvia as well as the airspace over the high sea encompassed by the Riga Flight Information Region in accordance with the regional air navigation agreement.

  1. Use of asterisk to identify published geographical co-ordinates

Not applicable.

   GEN 2.1.4 VERTICAL REFERENCE SYSTEM

  1. Name/designation of the reference system

The vertical reference system used is Latvian normal height system at epoch 2000,5.

  1. Description of geoid model used

The quasigeoid model LV'14 is used, the accuracy of LV'14 is 4.0 cm. The model is available on the website of Latvian Geospatial Information Agency https://www.lgia.gov.lv/en/latvian-quasi-geoid-model

The differences between LV'14 and Earth Gravitational Model 1996 (EGM-96) vary from -21 cm to 80 cm in the territory of Latvia.

LV'14 and EGM-96 difference surface, description of its preparation, difference conversion calculator are available on the website of Latvian Geospatial Information Agency https://www.lgia.gov.lv/en/latvian-quasi-geoid-model-lv-14-and-earth-gravitation-model-1996-egm-96

  1. Use of asterisk to identify published elevations/geoid undulations

Not applicable

   GEN 2.1.5 AIRCRAFT NATIONALITY AND REGISTRATION MARKS

The nationality mark for aircraft registered in the Republic of Latvia is the letters YL. The nationality mark is followed by a hyphen and a registration mark consisting of 3 letters e.g. YL-AAA.

   GEN 2.1.6 PUBLIC HOLIDAYS

NAME

DATE/DAY

New Year’s Day

01 JAN

Good Friday

FRI before Easter

First Easter

Easter SUN

Easter Monday

MON after Easter SUN

Labour Day

01 MAY

Independence Declaration Day

04 MAY

Mother’s Day

2nd SUN of MAY

Pentecost

7th SUN after Easter

Ligo Day

23 JUN

Janis Day

24 JUN

Independence Day

18 NOV

Christmas Eve

24 DEC

Christmas Day

25 DEC

Boxing Day

26 DEC

New Year’s Eve

31 DEC