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