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On the floor monitors you can see real-time traffic camera pictures. |
There is an enlarged aerial photograph of the capital region on the floor of this exhibition section. The picture is 120 square metres large and it is on the scale of 1:2250 which means that 1 cm on the floor is equivalent to 22,5 metres in terrain. The main traffic routes of different means of transport have been marked on the aerial photograph. On the floor monitors you can see real-time traffic camera pictures. The red led-lights indicate the real-time speed of the flow of traffic on a certain focus area. The real-time traffic information is gathered from the LAM system maintained by the Finnish Road Administration. In Finnish LAM stands for the automatic measurement of traffic.
Traffic is always co-operation between the different means of transport. Traffic routes form a network that joins different regions and functions (such as residence, industry, business centres) together.
Co-operation partners:
National Land Survey of Finland
Finnish Road
Administration
Automatic measurement of traffic
— LAM
Two consecutive
indicator loops that have been embedded in the road recognise each
vehicle. The measurement equipment has been programmed to save the
time of each passing with an accuracy of one hundredth of a second.
In this way, it’s possible to calculate distances between
vehicles etc. The equipment saves information such as time,
direction, lane, vehicle class, length and speed of each passing
vehicle. Vehicles can be divided into seven different
classes:
- 1 passenger and delivery cars
- 2 lorries
- 3 buses
- 4 lorries with half a caravan
- 5 lorries with full caravan
- 6 passenger and delivery cars with trailer
- 7 passenger and delivery cars with house trailer or a long
trailer for example for boats
The information is read automatically every night and gathered through a modem to a computer in Helsinki. Hourly information — such as the amounts of traffic, distances between vehicles, amounts of vehicles in different speed groups — is being calculated, from some measurement points the calculation is performed every five minutes. This information is saved in a database, and the raw data files are saved on a server for possible further use in research.
Information is gathered from some of the LAM stations every 5-10 minutes. Thus, the busiest routes are in real-time monitoring.
Aerial photographs
An aerial photograph is a useful and illustrative means of observing the terrain and its details. In an aerial photo you can see vegetation, buildings, roads and other details that do not stand out from maps.
Aerial photography is the basis of map making. These photos can be used for several purposes:
- Preparing terrain maps and digital orthophotos
- Plannig roads and railways
- Estimating the tree stand of a forest, its condition and possible damages. This is almost always performed with infrared pictures.
- Estimating eutrophication with colour or infrared pictures
- Productivity research of field growth segments with infrared pictures
- Estimating floods and ice conditions
- Historical and archaeological research. It’s possible to see the location of buildings and roads that have disappeared centuries ago if the aerial photo is taken in good conditions. Also the underdrain network or old open ditches, that have been covered by current fields, can be seen. With this information it’s possible to estimate ancient grounds and their boundaries.
- Planning power lines and radio links
- Planning golf courses and slalom slopes etc.
The National Land Survey of Finland up-dates a terrain database and takes photographs of nearly 15 % of the surface area of Finland each year. The photos are mostly black and white but also infrared photos have been taken from some, large areas.
The altitude of an aerial photography session is dependent on the accuracy needed and costs involved. The planes of the National Land Survey of Finland fly between 500 - 9 000 metres. Thus, the photos are being taken on the scale of 1:2 500 - 1:60 000, depending on the objective. The picture size of the cameras is 23 x 23 cm, which means that the side of the picture is 1 x the flight altitude in terrain with an intermediate lens and 1,5 x flight altitude with a wide-angle lens.
Aerial photographs are available from all parts of Finland. In some areas there are aerial photos dating back to the 1940’s. The Aerial Image Centre has an archive of altogether 600 000 originals, out of which enlargements can be made in different scales. Customers can also have their own films scanned at the Aerial Image Centre. The oldest aerial photographs are from the 1930’s.
The Aerial Image Centre of the National Land Survey of Finland performs all aerial photograph sessions that are needed for national terrain mapping and register mapping productions.
For more information:
Maanmittauslaitos The National Land Survey of Finland
Updated 8.1.2007/KT
