Surveying and Mapping Flashcards
Tell me about your understanding and the importance of accuracy for mapping.
Errors can lead to impacts on valuation and legal issues
Tell me about a data capture technique you have experience of using.
LandInsight
ProMap
What are the knock on effects of this technique for accuracy and precision?
Area taken - apply density assumption to, will impact yield of homes applicable to the valuation
How do you check that your instruments are accurate/calibrated?
Laser distometers are typically accurate to within 1.5mm or less over distances up to 200m, although this will depend on the device used. Annual calibration is important to ensure accuracy, typically by sending the laser distometer back to the manufacturer. Taking check measurements over a known distance can also ensure accuracy on a more frequent basis
What is BIM?
Building Information Modelling - allows for 3d walkthrough model of the development to be created
What is GIS?
Geographic Information System - A geographic information system (GIS) is a computer system for capturing, storing, checking, and displaying data related to positions on Earth’s surface
What is digital terrain modelling?
What is a digital terrain model?
Digital Terrain Models (DTM) sometimes called Digital Elevation Models (DEM) is a topographic model of the bare Earth that can be manipulated by computer programs. The data files contain the elevation data of the terrain in a digital format which relates to a rectangular grid.
What are digital elevation models?
A Digital Elevation Model (DEM) is a representation of the bare ground (bare earth) topographic surface of the Earth excluding trees, buildings, and any other surface objects.
What are Global Navigation Satellite Systems (GNSS) and how can they be used in land surveying?
Global Navigation Satellite Systems (GNSS) include constellations of Earth-orbiting satellites that broadcast their locations in space and time, of networks of ground control stations, and of receivers that calculate ground positions by trilateration.
What is GPS?
an accurate worldwide navigational and surveying facility based on the reception of signals from an array of orbiting satellites.
What is a map?
a diagrammatic representation of an area of land or sea showing physical features, cities, roads, etc.
What are the three main forms of mapping?
(1) general purpose - display natural and man-made features of general interest (widespread use)
(2) thematic - They highlight features, data, or concepts, and these data may be qualitative, quantitative, or both
(3) cartometric maps - Cartometrics, or cartometric analysis, refers to mathematical operations such as counting, measuring, and estimating—thus, cartometric maps are maps which are optimized for these purposes
What are the main map scales used for HM Land Registry Plans or those used in your jurisdiction?
The scale of a title plan is usually 1:1250 in urban areas and 1:2500 in rural areas
What is the Ordinance Survey?
Ordnance Survey (OS) is Great Britain’s national mapping agency. It carries out the official surveying of GB, providing the most accurate and up-to-date geographic data, relied on by government, business and individuals.
Tell me about a digital mapping software you have used.
Landinsight, Promap
What are the advantages of using digital mapping?
- the ability to dynamically change the topography and location of various objects;
quick terrain scaling; - higher accuracy and absence of distortions;
- possibility of digital marking and instantaneous search for the necessary object;
- automatic routing and control over deviations from the selected course;
- possibility of transferring digital maps via Internet.
Where are OS maps generally used in your scope of work?
Boundary demarcation
Tell me about a type of map you use in your role.
Google maps
OS Mastermap - location plan for planning application
What is a title plan?
Outlines property interest (freehold or leasehold) that relates to the associated register
In addition to showing the land in a registered title, a title plan may contain other plan references which identify any parts of the land or adjoining land affected by entries in the register, such as easements, covenants or areas of land removed from the title.
What is a vector map?
A vector map, like OS MasterMap, is basically a database of points, lines and polygons which collectively make up all the features on the map. It’s possible to assign each of these features extra information – perhaps demographic data and the age of the buildings for example
What is the OS MasterMap?
It is a database that records every fixed feature of Great Britain larger than a few meters in one continuous digital map
What is a topography layer?
Shows elevation and gradient
Why is it important to keep maps updated?
To ensure that material changes to a site’s condition, location or situation are accounted for in reporting
What is OS VectorMap Local?
A highly-detailed, customisable, street-level base map, OS VectorMap Local shows fences, building outlines, paths and street names, for the accurate lie of the land. A simple vector dataset at a nominal scale of 1:10000 covering the whole of Great Britain designed for creating graphical mappin
Do OS Maps show legal boundaries?
OS maps don’t show legal property boundaries or ownership of physical features.
Tell me briefly about your understanding of licensing in relation to mapping.
Licensing in relation to mapping refers to the legal agreements and permissions that govern the use, distribution, and sharing of geographic or cartographic data, as well as the software and tools used for creating, viewing, or manipulating maps
What RICS guidance relates to the measurement of land?
RICS Professional Standard - Land Measurement for Planning and Development Purposes
Who should apply this guidance in practice? (RICS Professional Standard - Land Measurement for Planning and Development Purposes)
It provides global best practice, but practitioners will need to be aware of any local jurisdictional requirements that may have superior authority.
What are LIDAR and ISFAR?
LiDAR stands for Light Detection And Ranging
What are the uses of aerial photography?
Mapping
Drone photography to show site condition
3D survey
What is a DTM?
Digital Terrain Model: is a digital representation of the terrain or a structure (gathered by scanning) that can then be utilised within CAD software to undertake design for further construction works
