About the Waypoint Database

Contents


Introduction

The Norwegian waypoint database contains more than 400 accurately defined waypoints in the Southern part of Norway.  

NAK, S/NLF has no liability for the consequences of using the data, for instance in navigation systems and cross-country flying.

The database was revised and updated according IGC recommendations before the 2007 season. This document provides some useful information about the database, and the conventions used for the waypoints.

The database is established and maintained by the help of ArcGIS software, using aerial photographs (ortophoto) as background map (see Norge i Bilder).  All waypoints have been clicked into the map to prevent typing errors on the coordinates. The waypoints are stored in ESRI shape files, and transferred to a mysql database on a web-server where its contents can be viewn and downloaded using a web-interface.

Changes from Earlier Versions of the Database

The most important change from earlier versions of the Norwegian waypoint list, is that all waypoints have been assigned a six-character identifier code. Additionally, the waypoint have been repositioned so they are placed accurately on the features they represent. Note that, since all waypoints are placed this way, coordinates on a waypoint may differ a few meters from earlier versions of the database. However, some waypoints from the old database had severe errors, and was moved more than four kilometers. Pay attention to this if you are used to flying towards particular features on the ground for a specific turn point.

Additionally, some waypoints were added to fill 'holes', while others were removed or moved in areas where points were close to each other.

The old waypoint numbers are preserved from the earlier versions of the database, except in the Western part of Norway. Here, the waypoints have been renumbered to match the outlanding catalog of Os Aeroclub. Hence, outlanding field 23 in this catalog will have waypoint number 23. South of Sognedfjorden (the fjord), outlanding points are number from 501 through 569, while other waypoints are numbererd 570 through 599.  North of Sognefjorden, waypoins are numbered from 600 through 699.

Organisation of the Database

The waypoints are stored in a mysql database on a Linux web server, and made available for viewing and downloading via a web-interface.  The database design is based on IGC recommendations, (though these are no longer available on the IGC-pages, but a copy is provided here for reference).

A formal specification of the database is avilable here.

Below, is sumary of the most important fields in the database:

code
This is the official 6-character waypoint identficator that is unique throughout the country. This will be the waypoint name in downloaded files, and it is suficcient to specify this identifier in written declarations. The three first letters in the code are taken from the waypoint title, while the remaining ones have been chosen to ensure uniqueness and to avoid possible mismatches. This makes it easier to find your waypoint in your navigation system while in cockpit.

The code is given in all upercase letters, and the following translations apply to the letters ÆØÅ:
  • Æ => E
  • Ø => O
  • Å => A

There is, however, an exception to this rule: "Våle krk" has code "VAALE", to make it more distinct from  "VALLE" (Valle krk). These waypoints are not too far apart.

Feature descriptions (bridge, church etc.) are never included in the waypoint code.

title
This is the full waypoint title. It is given with æøå and  with mixed casing (g.e. Åsnes krk). For many waypoints, the feature of the waypoint is also provided in the title, and these are usually abreviated.  Here is a list of the most common:

Åsnes krk
church
Starmoen flpl
airfield, airport
Gol st
railway station
Høyegga dam
dam
utel.
outlanding field.

For bridges, the feature name "bru" is not included in the title, unless the waypoint title is the actual name of the bridge. Ususally, the waypoint title is taken from the area/place where the bridge is located.

You can search on the waypoint title using most Norwegian web-maps (such as Norgesglasset).

lat/lon
Longitude and Latitude are on the following form: "DDD MM.mmmX". See below for information on waypoint placement.

exact
Provides, in English, an exact describtion of the feature that the waypoint represent. For example: "church", "bridge", "dam" etc.

type
A text string, where the presence of the following characters indicate the waypoint type:

T - turn point
F - finish point
S - start pont
A - airfield with hard surface runway
G - airfield with grass surface
L - waypoint is landable (outlanding field)
# - warning

See below for further information about the waypoint type.

alt
Waypoint altitude.  It is given with the unit of measure, for example: "134M". Altitudes are given in meters above sea level according Norsk height datum (Norsk Null 1954).  The accuracy should be within 20m, except for sloping fields.

findability

Findability of the point. This is a letter A, B, C, D or E for the ease of finding the point from the air, and N indicates No physical presence on the ground. Category A is good while, E is poor and might need local knowledge.

Most waypoints should be well visible and are classified as "A" or "B". Some outlanding fields, however, can be hard to identify amongst many other ('less landable') fields, and have visibility "C". Only a few waypoints are given with findability "N".


Meta Point - Version Identifiers

When you download a set of waypoints, you can choose to include an extra meta point. The purpose of this waypoint is to provide a way for the user to check the currency of the waypoint list currently uploaded to a GPS or navigation system, as such data is not usually provided by these systems.

The meta point will have the same coordinates as the chosen home waypoint, and has as code, as string on the form "NOYMD", where "YMD" represent the update date of the most recently updated waypoint in the downloaded set, and is interpreted as follows:


Y
is the last digit of the year, cycling every 10 year.
M
is the month, where 1=January, 2=February, ... 9= September, A=October, B=November, and C=December
D
day of month where,  A=10, B=11, ..., U=31.

Downloading Waypoints

You can either download a predefined waypoint list, or any set based on a geographical region (min and max latitudes and longitudes).

The web-interface offer a wide selection of waypoint file formats.  However, we did not have formal specifications of all formats, nor the possibility to test them. In particular, this applies to binary formats, of which the Filser format (LX / da4) is the only provided.

If you have problems with a file format, do not hesitate to contact the administrator on this form; if the problem is identified, a fix can usually be provided fairly quickly.

Waypoint Placement

If you like to check on the ground while approacing a waypoint, the following information may provide useful:

  • Waypoint on airfields are placed on the runway, in front of taxiway, terminal building or other main building.
  • Railway stations are placed on the railway track in front of the station building.
  • Bridges and Dams are placed on the middle.
  • Lakes are placed in the South/North/West/East shore of the lake, or on river inlets or outlets.
  • Churches, Hotels and other buildings are placed in the middle of the building. Farms, however are placed in the middle of the farm yard.
  • (Outlanding) fields are placed in the middle of the field.

Waypoint Types

Pleace note the following concerning the waypoint type:

  • Start points have type "S", and only "S"
  • Finish points have type "F", and only "F"
  • In the Western part of Norway (waypoint numbers 500 through 699), outlanding options are rare, and waypoints are mostly placed on or near landable fields.  These waypoints are given type "TL". Hence, waypoint in this area of type "T" are not near any landable features.
  • There is no homepoint ("H") in the database, you choose this amongst available airfields at download time.