Above Ordnance Datum is a reference elevation used in surveying that is based on the mean sea level. It provides a standard benchmark for measuring height or altitude across different locations. This datum is commonly used in the UK and other countries for mapping and surveying purposes.
An Ordnance Survey Bench Mark is a surveying mark made by the Ordnance Survey to record heights above Ordnance Datum. They are typically found on buildings, bridges, or other structures and are used as reference points for altitude measurements.
A datum in land surveying is a known point or elevation used as a reference when measuring and mapping the land. It serves as the basis for establishing the positions of other points, helping to ensure accuracy and consistency in surveying work. Common datums include the North American Datum (NAD) and the World Geodetic System (WGS).
The datum used to start a survey in land surveying typically refers to a known point with established coordinates. This point serves as a reference for all other measurements taken during the survey. It is essential for ensuring accurate positioning and alignment of survey data within a specific coordinate system.
Reduced level in land surveying refers to the vertical distance from a known elevation point, such as a benchmark, to a point of interest on the ground. It is typically used to determine the height or depth of a specific location relative to a reference point.
Common types of data used in cadastral surveys include boundary data, parcel data, easement data, and ownership data. These data are essential in establishing land ownership, defining property boundaries, and maintaining accurate land records for legal and planning purposes.
An Ordnance Survey Bench Mark is a surveying mark made by the Ordnance Survey to record heights above Ordnance Datum. They are typically found on buildings, bridges, or other structures and are used as reference points for altitude measurements.
above ordnance datum!
The highest motorway in the UK is the M62 near the boundry between Yorkshire and Lancashire which reaches 372 metres (above ordnance datum)at it's peak. == ==
Sea level rises and falls, so a datum line was put by the British Ordnance Survey on a harbour wall at Newlyn, Cornwall. It is from this datum line that mean sea level is measured.
AHD stands for Australian Height Datum, which is a reference system used in surveying to measure heights and elevations. It is commonly used in Australia to establish consistent vertical measurements across different locations.
Land-surface datum is a datum plane that is approximately at land surface at each well. If known, the elevation of the land-surface datum above sea level is given... Datum: any level surface, line, or point used as a reference in measuring elevations.
any level surface from which vertical distances of the points above or below this surface are measured is known as datum
A datum in land surveying is a known point or elevation used as a reference when measuring and mapping the land. It serves as the basis for establishing the positions of other points, helping to ensure accuracy and consistency in surveying work. Common datums include the North American Datum (NAD) and the World Geodetic System (WGS).
RL stands for Reduced Level in terms of elevation. It refers to the height of a point or feature above a chosen reference point, usually a specified datum or benchmark. RL is commonly used in surveying, construction, and engineering to describe vertical measurements.
Take a look at this Ordanance Survey page. http://benchmarks.ordnancesurvey.co.uk/pls/htmldb/f?p=111:7:6255072357299077241::NO:7:: Type in a kilometer square grid in the form "SP9013" for instance. This page will give you a conversion factor. It seems a little ambiguous as to whether the figure they give you is to convert Newlyn to Liverpool or vica versa. I am still investigating.
Ordnance survey maps are maps that show altitude in relation to a 'known' ordnance datum. An ordnance datum is a point of particular altitude. In the UK, that ordnance datum for ordnance survey maps is the mean sea level at Newlyn in Cornwall. Ordnance survey maps typically show topography, by means of contour lines and spot heights. General land detail, such as grass-land, forest, marsh. In addition roadways, railways, footpaths and bridleways are shown. This makes ordnance survey maps of particular use for anyone wishing to navigate on foot. And this remains one of the most popular uses for this type of map. Ordnance survey maps are maps that show altitude in relation to a 'known' ordnance datum. An ordnance datum is a point of particular altitude. In the UK, that ordnance datum for ordnance survey maps is the mean sea level at Newlyn in Cornwall. Ordnance survey maps typically show topography, by means of contour lines and spot heights. General land detail, such as grass-land, forest, marsh. In addition roadways, railways, footpaths and bridleways are shown. This makes ordnance survey maps of particular use for anyone wishing to navigate on foot. And this remains one of the most popular uses for this type of map.
It is a fixed reference point whose elevation above a given datum line