Exam (elaborations)

GIS Exam Questions and Answers 2024/2025

0 purchase

Module
GIS

Institution
GIS

Why can getting points from a GPS into ArcGIS be problematic?  Poor connection - hardware and software issues; different companies/products/versions Difficult to find the specified datum/projection What is remote sensing? Give examples.  Collecting information from a distance; ex. photo...

[Show more]

Preview 4 out of 31 pages

View example

Uploaded on October 10, 2024
Number of pages 31
Written in 2024/2025
Type Exam (elaborations)
Contains Questions & answers

gis exam questions and answers
why can getting points from a gps into arcgis be p

Institution GIS
Module GIS

TestTrackers

Member since 11 months 94 documents sold

£11.51

Add to cart

Add to wishlist

100% satisfaction guarantee
Immediately available after payment
Both online and in PDF
No strings attached

2 0 2 4 /2025 | © copyright | This work may not be copied for profit gain Excel!

GIS Exam Questions and Answers
2024/2025
Why can getting points from a GPS into ArcGIS be problematic?

 Poor connection - hardware and software issues; different
companies/products/versions
Difficult to find the specified datum/projection

What is remote sensing? Give examples.

 Collecting information from a distance; ex. photographs or radar/LiDAR. Typically
satellite or air plane. Offer great detail over a continuous surface

How is remote sensing imagery stored?

 Great detail = large file sizes. Stored using raster data models - typically, three
rasters superimposed together to get color (one each for Red, Green, and Blue value:
RGB)

How can we pull information from remote sensing?

 Can often be detected by the human eye and then digitized or classified based on
type; but is very time consuming and expensive. Plus, humans can make mistakes. So
we increasingly use computers to pull out the information correctly. Computers use
automatic processing, being trained to write rules to automatically pull out information.
This is hugely beneficial for large datasets. Not ideal for small areas.

What is artificial intelligence?

 Show computer what to look for and it figures it out; E.g. cancer on a brain scan,
gentrification on street view. Cutting edge of computer technology - but humans are
unsure of how it actually works. Computer is literally thinking for itself (training itself).
Huge potential moving forward - perhaps someday replace all humans

What is LiDAR?

1|Page| GradeA+ | 2 0 0 2 5

,2 0 2 4 /2025 | © copyright | This work may not be copied for profit gain Excel!

 Light Detection and Ranging - similar to SONAR, but uses laser rather than sound
waves. Device sends out a laser pulse, and records how long it takes for it to bounce
off surface and return to detector. Benefits: Highly Accurate; can penetrate foliage

How are drones used in RS and what is their benefit

 Similar to RS from air photos or satellite. However, much cheaper to collect the
information and can be collected by user at will, rather than relying on someone else's
satellite.

How can smart phones be used for data collection?

 Because they are hugely powerful data collection devices, with a large number of
sensors (accelerometer, GPS, gyroscope, microphone, barometer, thermometer). Have
lots of storage for data, cloud connections, and high processing speed. The fact that
our phones are constantly collecting data about us creates massive privacy issues.

Define projections and coordinates.

 Projections compensate for the earth being spherical but being represented on a flat
surface (map)
Coordinates allow us to accurately and reproducibly locate features on the earth's surface

Define geodesy

 Science of measuring the shape of the earth - humans have been refining the model
for thousands of years

Describe earth's shape.

 Earth is an Ellipsoid, not a perfect sphere. Two radii:
•r1, along semi-major (through Equator)

•r2, along semi-minor (through poles). More specifically, its shape is a geoid, because it is

rough, not smooth, due to differences in internal gravitational pull. This causes some areas to

bulge out while others are sunken.

1|Page| GradeA+ | 2 0 0 2 5

,2 0 2 4 /2025 | © copyright | This work may not be copied for profit gain Excel!

What is essential for defining x/y coordinates?

 The poles and equator

Define datum.

 A model of the earth's size/shape (ie a model of the Geoid). Applied to a specific
origin/reference point. Different datums created for places around the world.
Continually refined over time (ex: NAD 27 vs 83). Not much change in recent decades.
Horizontal and Vertical datums exist

With projections, is there more distortion on small scale or large scale maps?

 Small scale maps

Projections typically only maintain 1 or 2 of what following features, and must distort at least

one feature?

 Area, shape, distances, and angles

Define spherical coordinates.

 Use the length of a vector originating at the ellipsoid center to define the location on
the surface

Define latitude and longitude.

 Latitude: Lines running parallel east to west; Equator is the baseline

Longitude: Lines running from pole to pole; Meridians; Greenwich (Prime) Meridian is the

baseline from which measurements are made

1|Page| GradeA+ | 2 0 0 2 5

, 2 0 2 4 /2025 | © copyright | This work may not be copied for profit gain Excel!

Define UTM.

 Divides the world into 60 zones (including North and South). Each zone has an origin
based on False Easting/Northing

Describe the relationship between GIS, coordinate systems, datum and projections and what

happens in GIS when they differ.

 Each layer has a coordinate system, and datum (usually projection) - even if it is not
defined. All layers on the map must be in the same system to allow them to line up
(superimpose). Thus, GIS projects on the fly to one system for all of the different
layers. Data frame has one projection/coordinate system which is defined by first file
added. All others that differ are re-projected on the fly to match this one.

What is the name of the file that contains projection information?

 PRJ

How can you see the projection information for the layer? For the data frame?

 Layer: go to properties >> source
Data frame: go to properties >> coordinate system

How can projections cause issues?

 •Often the projection/coordinate/datum information is missing or incorrect
•E.g. bringing in GPS data

•If information is wrong/not specified, major problems for your data

•Will be plotted in the wrong location

•Often just float out in space

•Will not line up between the layers

•Warning Message for Geographic Coordinate Systems not Aligning

1|Page| GradeA+ | 2 0 0 2 5

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

You can quickly pay through credit card for the summaries. There is no membership needed.

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller TestTrackers. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £11.51. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

69411 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy revision notes and other study material for 15 years now

Start selling

Exam (elaborations)

GIS Exam Questions and Answers 2024/2025

Document information

Subjects

Written for

Seller

Reviews received

Content preview