Frequently Asked Questions

concerning all kinds of questions we encountered about spatial data analysis and software

… and continuously updated

Frequent Questions about Earth Observation Application:

Below we add some FAQs concerning Earth observation, but of course, they cannot cover an entire course or even a complete M.Sc. program. However, we try to add all crucial information.

Frequent Questions about Earth Observation software:

Various Earth observation software solution exist either GUI or CLI based. We focus on open-source solutions to facilitate its wide application without licensing limitations.

How do I know what kind of Earth Observation exist?

The main distinctions are made on the nature (passive or active) of the sensing instrument providing the image and on the wavelength of the electromagnetic spectrum in which the observation is made. The electromagnetic transparency of the atmosphere allows for the observation of Earth’s surface in the visible spectrum (0.39 to 0.70 μm), in a part of the infrared spectrum (from 0.70 to 14 μm) and in the radio wave range (from 1 cm to 11m) ESA.

What means GUI and what is a CLI?

Any device’s operating system is nothing but an interface between the user and hardware components of that device. The operating system offers a GUI vs CLI user interface to interact with an electronic device. Some operating systems provide GUI and CLI, while others offer only CLI. GUI means a Graphical user interface while CLI means the command line interface. As the name suggests, one has to write commands to perform a certain CLI system task. On the other hand, GUI offers graphics that consist of icons and images that enable users to do a task directly. CLI requires expertise in commands for performing a certain task, while a beginner can operate GUI.

Which data portals do we use?

To get an introduction to the world of data portals, it is enough to register with the following portals to get started.

Scihub ESA

Sentinel Hub

Google Earth Engine

What Does a Remote Sensing Specialist Do?

Remote sensing specialists support scientists by designing and conducting remote sensing data gathering efforts. For example, they determine the best techniques, equipment, spectral band, and time of day for a particular mission. They may prepare flight plans, configure sensors, apply the techniques to collect data in the field, and process the resulting data.

This data is used in a wide variety of fields, including all of the environmental sciences, agriculture, archaeology, urban planning, water management, meteorology, and even engineering and business.

However, before it can be used, remote sensing specialists must verify the integrity and accuracy of data and correct any errors due to atmospheric variation or other interference. They may also build photo mosaics of large areas, participate in the planning or development of mapping projects, and integrate remotely sensed data with other geospatial data to create maps. Many use computer programming languages like Python to automate data processing tasks. They may also create metadata that documents the datasets so that others will understand their context and characteristics (cited from environmentalscience.org)

Which scientific (open-source) softwares exist?

You don’t have to spend a fortune to map the world. Because you can do it all with free GIS software.

Open source refers to software whose source code is public and can be viewed, modified and used by third parties. Open source software can usually be used free of charge.

In the geopsatial context, there is quite a bit of open source software. For the beginning it is enough to have a look at the following.

QGIS

GrassGIS

SagaGIS

Whitebox

OrfeoToolbox

RStudio

Python

Of course, you don’t have to master all of these softwares at once. It should only give you a first overview and show you what variety of software exists. For the beginning it is enough if you install QGIS, which has many of the following mentioned softwares already integrated.

First steps to get your QGIS running

Install QGIS on your favourite operating system.

QGIS Download

Get to know your new geospatial friend.

QGIS for beginners tutorial

(follow Klas Karlsson on twitter to stay up-to-date with open source geospatial news)

Next step, install your first plug-ins.

Plug-in tutorial

For the start install the following plug-ins:

Quick map Services
Data plotly
GEE Plugin
SCP

(use the same QGIS Documentation to dive deeper into the subject)

Resources