C H A P T E R

N ° 23

Space Weather and Autonomous Vehicles

In recent years, fully autonomous vehicles have been highly debated. Risk and vulnerability assessments have been made for numerous potential terrestrial weather scenarios. Yet, it is only in recent years, that weather interferences from space have been considered. Research on space weather impact on these future vehicles are, therefore, sparse. However, as the goal of the automotive industry is to create fully autonomous vehicles, this article attempts to highlight and stress the need for space weather to be equally considered in the research and development, and risk and vulnerability assessments of autonomous vehicles.

In SR Hoplon’s most recently published article; C H A P T E R N ° 22 Space Weather and The Road Transport Sector, we discussed the relation between space weather, the road transport sector, and the ground transportation systems. Additionally, we looked closer at the relation between space weather, current electrical vehicles (EVs), and future fully autonomous vehicles. Lastly, we explored and discussed the challenges of developing effective mitigation measures. This article will build on the knowledge and discussions provided in that article. In order to fully understand this article, the reader may wish to read Chapter N ° 22 beforehand or afterwards. Additional relevant articles recommended to read will be provided under each section discussing the related topic.

In today’s article, we will look closer at the relation between space weather and fully autonomous vehicles. Moreover, we will explore how space weather interferes with the process between satellites and ground receivers, and how this can increase safety risks and reduce proper driving capabilities for autonomous vehicles. SR Hoplon will provide an overview and discuss the connection between the implemented advanced technologies within autonomous vehicles, and their dependency on critical space infrastructure.

Radio waves and optical communication

Understanding space weather impact on technologically advanced inventions such as fully autonomous vehicles demand an awareness and understanding of the signal transferring process between satellites and ground receivers, and this process in relation to space weather.

Satellites orbiting Earth are floating computers in the vast reaches of space with their primary task being to gather and disseminate information, forming an intricate constellation of data exchange. They typically send signals back to a satellite operating station on the ground, or ground receivers that furtherly transmits the data to the next satellite. Most communication satellites sending back data to Earth use radio frequencies (i.e., radio waves) or optical communications (i.e., Optical Communication Terminals (OCTs) (i.e., thermal radiation)).

Radio waves are a type of electromagnetic radiation that has a longer wavelength than visible light. Visible light is the segment of the electromagnetic spectrum that the human eye can view. It has a wavelength ranging between approximately 400-700 nm (nanometers). In contrast, the wavelengths of radio waves arrange from a few millimeters to hundreds of kilometers, making the wavelength of visible light approximately 5000 times shorter than the shortest wavelength radio waves.

Optical communication (i.e., thermal radiation) uses higher frequency with shorter wavelength infrared light to transmit data. By using lasers to convert data into a light beam directed towards a ground receiver or another satellite, it enables faster data transfer compared to the traditional radio frequency methods. However, similar to radio waves, infrared light is a type of electromagnetic radiation. Its wavelengths range between approximately 780 nm (nanometers) to 1 mm (millimeter).

It is through these signal transferring capabilities, that satellite data is transmitted from the space environment to ground receivers and further to ground operating stations or other satellites. They enable services such as radio broadcasts, military communication, mobile phones, ham radio, and wireless computer networks, like the 5G networks.

* To learn more about radio waves and radiation on Earth contra radiation in space, please read: C H A P T E R N ° 3 The Outer Space Environment: Radiation vs Space Radiation. *

**Image Credit:** NASA: *The* *electromagnetic spectrum (EM).*

Space weather and satellites and ground receivers

Similar to terrestrial weather occurring on Earth, the Sun has its own continuous occurrence of weather. We, therefore, see activities happening on the Sun all the time. However, sometimes these activities reach a certain level of intensity, consequently causing them to interact with the Solar System. Yet, it is the phenomena created through the interaction between the Sun and the Solar System (i.e., planets, moons, and their surrounding space environment) that we call ‘space weather’. It is a condition and can be defined as a natural hazard comprising a wide range of phenomena caused by solar activities (i.e., activities happening on the Sun).

Furthermore, the Sun has an 11-year Solar Cycle that goes from solar minimum to solar maximum. During ‘solar minimum’ we see the least number of activities causing space weather, whereas the opposite occurs during ‘solar maximum’. However, this does not mean that we cannot experience space weather during solar minimum, or a time between two solar cycles.

As previously mentioned, satellites use radio frequencies and optical communication to transfer data to and from ground receivers. These are both a type of electromagnetic radiation. Similarly, space weather comprises electromagnetic energy in many wavelengths. Additionally, it is capable of emitting streams of radiation comprising electrically and magnetically charged particles into the near-Earth space environment, and through the Earth’s magnetic field and down into its atmosphere. During such events, the particles emitted from the Sun are capable of interfering with already present particles, changing the space and atmospheric environment. The signal transferring process between satellites and ground receivers depending on the process carried out by the electromagnetic radiation (i.e., visible light, radio wavs, ultraviolet, gamma rays, and high energy X-rays) sent from a satellite to a receiver are, therefore, significantly vulnerable to space weather.

A particularly vulnerable place on the Earth is within its atmosphere, more specifically within the ionosphere. The ionosphere is a region within the thermosphere (i.e., the second highest located atmospheric layer of Earth). It is localized at an altitude of approximately 60-300 km (kilometers). Under normal circumstances without space weather or during minor events, this region is able to absorb UV, X-ray, and cosmic rays. However, during stronger space weather events this region becomes highly complex. The ionosphere is, thus, an important region when discussing the interaction between the Earth and space weather.

**Image Credit:** n2x: *Showing the different atmospheric layers of Earth and their altitudes.*

The thermosphere and, thus, the ionosphere are both dependent on the Sun’s 11-year activity cycle. For example, Earth-directed solar activity causing severe and extreme space weather impact can change the density of the ionosphere and make it thicker (i.e., more dense). Solar activities such as solar flares are intense in UV and X-ray and can, therefore, change the composition of the ionosphere on the sunlit side of Earth during a solar flare event.

Within the ionosphere is a layer named the ‘D-region’. This region is the lowest layer of the Earth’s ionosphere (~60 km to 90 km altitude) and covers the mesosphere and lower thermosphere layer of the Earth’s atmosphere. Solar activities such as solar flares can thicken this region, as its photon particles can ionize the atmosphere as they penetrate to the bottom of the ionosphere, creating an enhancement of the D-region within the ionosphere. This enhancement enables the ionosphere to bend the path of radio waves or scatter them completely at some frequencies, and absorb them at other frequencies. As a consequence, it can cause things such as loss of Global Positioning System (GPS) signals and telecommunication blackouts. Communication issues associated with space weather impact in the form of – for example - solar flares often occurs on the dayside region of Earth.

However, similar issues can occur on the nightside region as well. Space weather caused by energetic solar protons can be guided by the Earth’s magnetic field in ways causing them to collide with the upper atmosphere (i.e., the exosphere) near the north and south poles. These fast-moving protons can - similar to the x-ray photons – enhance the D-region, consequently blocking radio waves, and, thus, cause disruption to communication at high latitudes. The interaction between incoming particles from the Sun and Earths’ atmosphere at the poles are commonly known to display aurora borealis (i.e., northern lights) and aurora australis (i.e., southern lights).

The ionosphere and the D-region within the Earth’s atmosphere are very complex environments, especially during severe and extreme space weather events. It is an uncertain and highly variable region on a variety of time scales, ranging from hours, days, and season to season up to the 11-year solar cycle. Sunspots have significant effect on the stability of the ionosphere due to the radiation emitted through the Sun’s activity’s ability to directly impact this region.

* Sunspots are temporary visible spots on the Sun’s surface that are darker than the surrounding area. It is a visible component indicating an active region on the Sun. *

***Image Credit:*** *NASA/Solar and Heliospheric Observatory: The Sun and sunspot Region 486 shown during the 2003 Halloween storm.*

It is very difficult to measure the ionosphere. Satellites cannot stay in the ionosphere, as it is too dense and would make the satellites re-enter the atmosphere, consequently causing them to burn up or land on terrestrial infrastructures. This means, that measurements are made by radar or rockets. However, these are difficult to move. We, therefore, only know a lot about the ionosphere at those locations and not around the whole globe. We can measure the ionosphere, but we cannot measure or see all the small and fine structures, which makes a lot of things remain unknown.

However, the variation of the ionosphere plays a significant role in the communication process between satellites and ground receivers. It determines the success of present communication and, thus, the transfer and return of signals to and from Earth.

* To learn more about space weather, the relation between space weather and the ionosphere and the rest of Earth’s atmospheric layers, please read: C H A P T E R N ° 1 Space Weather Basics, and C H A P T E R N ° 4 The Van Allan Belts, and C H A P T E R N ° 11 Space Weather and Earth’s Atmospheric Layers. *

Space weather and autonomous vehicles

Autonomous vehicles comprise a set of technologies to partially or entirely replace the human driver in navigating a vehicle, while avoiding road hazards and responding to traffic conditions. There are five stages of automation in automobiles ranging as followed:

Stage 0: No automation. The vehicle is fully operated by the driver. Driver assistance is provided in the form of warnings (e.g., blind spot or lane departure warnings).

Stage 1: The driver is fully in command of the vehicle with assistance from one automated feature, such as automated acceleration and braking for adaptive cruise control, or automated steering for lane centering.

Stage 2: The driver is fully in command of operating the vehicle. However, assistance from two automated features such as acceleration, braking or steering are implemented.

Stage 3: The vehicle operates autonomously but with the assistance of a human driver monitoring conditions and ready to take immediate control when the vehicle’s system alerts them.

Stage 4: The vehicle is fully self-operational within set boundaries. No attention or assistance is required from a human driver. The vehicle may, additionally, not have pedals or a steering wheel.

Stage 5: Fully self-driven vehicles with no requirements for a human driver to assist, monitor, or operate.

As described in the five stages of automobiles, regardless of vehicles being partially or fully automated, their functionality and sufficiency more or less depend on the well-functioning of satellites (i.e., critical space infrastructure). This furtherly implies a dependency on the conditions of the activities happening on the Sun and the Earth’s atmosphere.

The goal of the automotive industry is to provide fully autonomous vehicles. With this goal, the foundational elements of fully automated vehicle systems are machine learning and artificial intelligence (AI). Yet, these depend on and are enabled by satellites. Machine learning is used to train vehicles to learn from the complex data that they receive to improve the algorithms that they operate under, and to expand their ability to navigate the road. They, thus, rely on the data transmission and exchange capabilities enabled by for example 5G networks. Artificial intelligence (AI) enables the vehicles’ systems to make instant operational decisions without needing specific instructions for each potential situation encountered while driving. It uses connected vehicle technology to communicate with other vehicles and infrastructure in order to detect close-by objects and map its surrounding environment.

Powerful computer systems process the collected data, wherefrom discissions about vehicle operations are made, continuously adjusting steering, cruising speed, acceleration, and braking. This is all done through a continuous communication between the vehicles sensors constantly collecting information about its surroundings and sending it back to its computer system, wherefrom it is processed and decisions are made. This computer system is operated by artificial intelligence (AI) that continuously depend and runs on services provided by satellites. Furthermore, the entire vehicle system depends on the 5G network for quick response and communication between the vehicles’ systems. Thus, the vehicles depend on telecommunication satellite services and the Global Navigation Satellite System (GNSS).

**Image Credit:** Simon Ramsdale; Diodes: *Cartoon showing autonomous vehicle communication.*

Currently when discussing the challenges of creating autonomous vehicles, discussions entail the limitations of the technology and, thus, the different sensors used. Autonomous vehicles work on four primary sensors; camera, ultrasonics, radar, and lidar. However, each sensor has its own limitations. Camera-based sensors are unable to detect objects in foggy areas, rain, or in the night. Radar uses radio waves to detect vehicles and objects, and is accurate in all conditions of visibility. However, it is unable to differentiate the objects’ type without a human driver due to its longer wavelength. Lidar is a sensor with higher resolution and used to detect any object around the car’s surroundings. Laser beams do, however, not provide accurate results in weather conditions like snow, smoke, fog, or smog. By the use of ultrasonic waves and transmitter-receiver pair, ultrasonic sensors (i.e., short range sensors: ~2 meters) sends detects echoes from objects and obstacles. These are used for low-speed Advanced Driver Assistance Systems (ADAS) modules to detect obstacles in traffic congested areas, and for parking space detection and assistance. However, they do have limitation in range capacity.

Most - if not all - type of terrestrial (ground-based) weather interferences have been researched and discussed in regards to autonomous vehicles. Yet, it is only recently that weather interferences from space have been considered. Research on space weather impact on autonomous vehicles are, therefore, sparse. Today’s vehicles are not fully autonomous and can, therefore, not operate without the intervention of a human driver. However, as the goal of the automotive industry is to create autonomous vehicles, it demands for more research and communication between industry and academia, or establishments specialist in space weather and Disaster Risk Reduction (DRR) and resilience.

The sensors intended to be implemented on the fully autonomous vehicles will be interdependent in order to maintain safety. Additionally, they will depend on services provided by satellites and receivers on Earth. However, space weather can ionize the atmosphere increasing the density of the ionosphere, making the particles in this region able to bend the path of radio waves, scatter them completely, or absorb them. This can cause a loss of signals and satellite service blackouts. Space weather can, thus, interfere with the communication between satellites and the receivers within the autonomous vehicles, consequently providing incorrect information.

If the ionosphere gets too dense, communication (i.e., data exchange) blackouts or complete shutdown may occur between the satellites and the autonomous vehicles. Autonomous vehicles will most likely rely on 5G networks for simple functions such as starting the vehicle. Interferences or complete blackouts of the communication satellite services may, therefore, lead to drivers not being able to drive their vehicle or experiencing a reduction in the vehicles’ driving capabilities.

**Image Credit:** OneLap: *Cartoon showing how the Global Positioning System (GPS) works.*

These effects are mainly when focusing the impact from space weather on satellites. Additional effects may be felt through the impact of space weather on the energy sector and other critical infrastructures. To know more about this, please read SR Hoplon’s blog: C H A P T E R N ° 22 Space Weather and The Road Transport Sector.

The risk of incorrect information or a temporary blackout of communication increases safety risks for the passengers and their surroundings. The interaction and potential effects of space weather on autonomous vehicles, therefore, must be taken into account when creating such advanced inventions. A vehicle like a fully self-driven car depending on satellite services is highly vulnerable to space weather impact compared to current non or partially autonomous vehicles (i.e., automated vehicles). The current and future changes in the automotive industry’s way of designing and constructing vehicles will, therefore, determine the overall level of risk and vulnerabilities posed on future vehicles when discussing space weather impact.

Source

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