Survey and Mapping (Level 1) Flashcards
Tell me about your understanding and the importance of accuracy for mapping.
Accuracy in mapping is crucial it helps to inform our decision making whether that is about:
- Value
- Design
- Safety
How do you check that your instruments are accurate/calibrated?
Disto:
- Follow the Leica Guidance
- establishing a constant baseline, taking at least 10 measurements from a fixed point
Alternatively you can send your disto away for re-calibration
What is Geodesy?
Geodesy - is an applied mathematics discipline used to understand various aspects of the Earth
What are the basic principles of geodesy?
The basic principles of Geodesy are:
Shape - the geometric object it resembles in both general and specific terms. In general terms, we know it’s a sphere, but in specific terms, mountains and valleys skew that representation.
Orientation - the relative position of key features, like the magnetic poles, in relation to other things in the solar system and galaxy.
Gravity Field - the effects of gravity as we move away from the surface, whether it is constant over the entire surface, and other factors.
What are the 3 branches of Geodesy?
- gravimetric
- geometric
- satellite branches
Tell me about how geodesy is applied to mapping in your area of practice.
A geodetic survey determines the precise position of permanent points on the earth’s surface, taking into account the shape, size and curvature of the earth.
Geodesy is used to produce Topographical Surveys, OS Maps, Site and Location Plans
What is BIM?
BIM – Building Information Modelling -
a highly collaborative process that allows architects, engineers, real estate developers, contractors, manufacturers, and other construction professionals to plan, design, and construct a structure or building within one 3D model
What is GIS?
GIS – Geographic Information System - system that creates, manages, analyzes, and maps all types of data. GIS connects data to a map, integrating location data
What is digital terrain modelling?
Digital Terrain Modelling – is topographic modelling of the bare earth that can be manipulated by computer programming
What are digital elevation models?
Digital Elevation Modelling – is topographic modelling of the earth’s surface taking into account all persistent objects (vegetation, buildings etc)
What are Global Navigation Satellite Systems (GNSS) and how can they be used in land surveying?
Global navigation satellite system (GNSS) - a general term describing any satellite constellation that provides positioning, navigation, and timing (PNT) services on a global or regional basis
GNSS can be used for survey and mapping tasks, there are 3 types of surveys using GNSS
- control surveys – high accuracy
- detail surveys – medium accuracy
- positioning – low accuracy
Tell me briefly about your understanding of RICS Practice Standards GN13/2010.
The guidance note forms part of a series of specifications and guidelines intended to assist all those connected with the requesting, purchase and production of surveys and mapping material at all scales, by spreading good practice and seeking to avoid duplication of effort
Tell me about HMLR Practice Guide 40: supplement 1.
Describes the origins and scales of Ordnance Survey mapping and how this relates to plans prepared by HM Land Registry.
The main headings in this supplement are:
- Introduction
- Ordnance Survey mapping
- Scale and accuracy of Ordnance Survey mapping
- Feature representation on Ordnance Survey mapping
- Availability of Ordnance Survey mapping
- Copyright
- Contacting Ordnance Survey
What is GPS?
GPS – Global Positioning System - GPS is a form of GNSS that provides location, velocity and time synchronisation.
What is a map?
A symbolic representation of selected characteristics of a place, usually drawn on a flat surface
What is the difference between a plan and a map?
Plan – Uses a smaller scale and utilises true scale representation
Map – Is drawn at a scale that features cannot be seen
Tell me about a typical map scale and it’s applications.
OS Map used by the Land Registry
A title plan usually has an OS Map Scale of 1:1250
What are the main map scales used for HM Land Registry Plans or those used in your jurisdiction?
- Title Plan (OS Map) = 1:1250
- Site Plan = 1:500
- Location Plan = 1:1250 or 1:12500
Tell me about the application of one of these scales - 1:500
A scale of 1:500 means that the actual real-life measurements are 500 times greater than those on the plan or map
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.
Digital mapping software = Google Maps, Promap
What are the advantages of using digital mapping?
- Desktop Mapping
- Quick
- Save data
- Can be transferred and shared easily
Where are OS maps generally used in your scope of work?
- OS Maps are used by the Land Registry
What is a location plan and what are its’ key features?
Location Plan
- Scale 1:1250 or 1:2500
- North Arrow
- Show sufficient roads/buildings on land adjoining the application site
- Show application site boundaries and all land necessary to carry out the proposed development i.e. land required for access to the site from the road, outlined in red
- A blue line should be drawn around any other land owned by the applicant that is close or adjacent to the property
What is a site plan (block plan) and its key features?
Site Plan (also known as a block plan)
- Scale 1:100, 1:200 or 1:500
- Show the proposed development in relation to the site boundaries
- North arrow
It should also include the following – unless they would NOT influence or be affected by the proposed development:
- All buildings, roads and footpaths on land adjoining the site including access arrangements.
- All public rights of way crossing or adjoining the site.
- The position of all trees on the site, and those on adjacent land.
- The extent and the type of any hard surfacing.
- The boundary treatment including walls or fencing where this is proposed
What is a red line plan?
A red line plan denotes site ownership
What other colours might you find on a map?
Blue line denotes any other land under the ownership close to or adjoining the application site
What is a title plan?
A title plan shows a properties general location and boundaries, as well as areas affected by covenants and easements
What is a title plan used for?
The purpose of the title plan is to support the property description in the register by providing a graphic representation and identifying the general extent of the land in a registered title
What is a raster map?
A raster map is basically a ‘dumb’ electronic map image made up of a set number of pixels. You can’t manipulate the information, move a place name around for example, and when you zoom into the map, it quickly becomes pixellated and unreadable, just like a photo taken on a digital camera
What is a vector map?
A vector map is a database of points, lines and polygons which collectively make up all the features on the map
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?
It provides an accurate visual context to help you interpret addresses, routes and imagery provided by the other layers.
What is the Integrated Transport Network layer?
A dataset containing details of Great Britain’s transport network.
Why is it important to keep maps updated?
To make sure you are working from the most relevant data and maps
Do OS Maps show legal boundaries?
OS maps don’t show legal property boundaries or ownership of physical features
Explain the key principles of the RICS Guidance Note Boundaries 4th Edition
RICS Guidance Boundaries: procedures for boundary identification, demarcation and dispute resolution
Looks at the seven stages of a boundary dispute instruction:
- Stage 1 – setting up the project
- Stage 2 – research
- Stage 3 – site visit, measured survey and photography
- Stage 4 – the report
- Stage 5 – alternative dispute resolution
- Stage 6 – litigation
- Stage 7 – recording the outcome in HM Land Registry
What RICS guidance relates to the measurement of land?
RICS Guidance Note Land Measurement for Planning and Development Purposes (2021)
What measurement bases does RICS Guidance Note Land Measurement for Planning and Development Purposes (2021) introduce?
- Land Ownership Area - A single legal interest or title is typically delineated by a red line on title documents. Each relevant LOA should be measured to this legal boundary
- Site Area - describes the area of land submitted in the planning application drawings that is subject to an application for permission for a particular development
- Net Development Area
- Density measurements : plot ratio and site coverage
What is LIDAR?
Lidar - Light Detection and Ranging — is a remote sensing method used to examine the surface of the Earth
What is IFSAR?
IFSAR - Interferometric Synthetic Aperture Radar (IFSAR) is an innovative technique which uses synthetic aperture radar (SAR) images from two spatially separated apertures and measures the phase difference between corresponding pixels in the two images as a measure of the path difference from the pixel to each aperture
What are the uses of aerial photography?
Marketing Images
Used in the following maps:
- Transmission Lines
- Road and Railway Engineering
- Water supply and power schemes
- Land drainage and flood prevention
What do you understand from the RICS Guidance Note Earth Observation and Aerial Surveys 6th Edition?
RICS Guidance Note Earth Observation and Aerial Surveys (2022)
It will help clients communicate their goals, and what they expect to receive in terms of:
- types of data
- accuracy
- resolution
- survey detail and
- final deliverables
Following topics are covered in this professional standard:
Chapters 2–3: pre-project considerations, including the different data capture platforms available and planning requirements
Chapters 4–7: the techniques of aerial photography, LiDAR, sensing in the non-visible part of the electromagnetic spectrum and Earth observation and
Chapter 8: future developments in Earth observation and aerial survey techniques.
What needs to be included on a site plan for a planning application?
A site plan used in a planning application should include the following:
- title of project or site
- north point
- scale (1:500)
- site boundary (red line boundary)
- drawing reference number
- position of fixed buildings
