'raytrace' function for LEO satellites (2024)

32 views (last 30 days)

Show older comments

Guillem on 24 May 2024 at 7:59

  • Link

    Direct link to this question

    https://in.mathworks.com/matlabcentral/answers/2122186-raytrace-function-for-leo-satellites

Edited: recent works on 24 May 2024 at 9:11

Hello!

I've been trying to use the function 'raytrace' to model the multipath propagation of a signal with a LEO satellite as a transmitter. I have a doubt regarding the 'raytrace' function itself:

I've noticed that for big tx-rx distances you need to set pm.AngularSeparation (which is the Average number of degrees between launched rays) to the minimal value to actually get some multipath. Still, for the case of LEO (for example, using a satellite flying at 400 km of altitude), the minimum angular separation you can put (= 0.05) does not give a multipath channel, and 'raytrace' only shows the Line-of-Sight even for a very dense urban scenario.

This doesn't happen if the tx-rx distance is lower (I've tried with a very low altitude satellite, for example), and in fact the lower the distance the more multipath you get. This seems to happen not because of the different geometry but because of the limitation in pm.AngularSeparation.

Is there any way to solve this?

Thank you in advance,

Guillem

0 Comments

Show -2 older commentsHide -2 older comments

Sign in to comment.

Sign in to answer this question.

Answers (1)

recent works on 24 May 2024 at 9:11

  • Link

    Direct link to this answer

    https://in.mathworks.com/matlabcentral/answers/2122186-raytrace-function-for-leo-satellites#answer_1462816

Edited: recent works on 24 May 2024 at 9:11

To address the issue of insufficient multipath rays when using the 'raytrace' function for a LEO satellite transmitter at high altitudes, you need to consider a few aspects related to ray tracing and the parameters used. Here are some strategies and potential solutions:

  1. Increase Ray Density Beyond Default Limits:
  • The limitation you're encountering with the pm.AngularSeparation parameter suggests that the default minimum of 0.05 degrees is not fine enough for your application at 400 km altitude. One way to handle this is to modify the underlying code of the 'raytrace' function (if possible) to allow for a smaller angular separation. This might involve changing the limits within the function's source code or configuration files if you have access to them.

2. Use Subdivision Techniques:

  • Another approach is to implement a ray subdivision technique where rays are further subdivided during the simulation based on certain criteria, such as distance from obstacles or areas of interest. This can help in generating more rays in critical regions without overwhelming the entire simulation with excessive rays.

3. Increase the Number of Launched Rays:

  • If the raytrace function allows for specifying the total number of rays to be launched, increase this number significantly. This may help in covering more paths, especially in dense urban environments where reflections and diffractions are more common.

4. Optimize Scene Geometry:

  • Ensure that the scene geometry (buildings, obstacles, etc.) is detailed enough to create opportunities for multipath reflections. Sometimes, insufficient detail in the urban environment model can lead to fewer interactions of rays with the scene.

5. Use Hybrid or Alternative Methods:

  • Consider hybrid methods that combine deterministic ray tracing with statistical models for multipath propagation. Techniques like the image method for reflection calculation, combined with stochastic models for diffraction and scattering, might offer a more comprehensive multipath profile.

6. Parameter Sensitivity Analysis:

  • Conduct a sensitivity analysis on other parameters that might influence the ray tracing results. Parameters like the reflection and diffraction coefficients, the resolution of the urban scenario, and the environment's electromagnetic properties can significantly impact the multipath characteristics.

7. Custom Ray Launcher:

  • If the existing function is too restrictive, develop a custom ray launcher that more densely samples the angular space. This custom launcher can be integrated with your existing simulation framework to ensure a higher density of rays, particularly for longer distances.

8. Post-Processing Multipath Analysis:

  • After running the raytrace function, perform a post-processing step where additional potential paths are generated based on the initial results. This step can include generating new rays from the endpoints of the initially traced rays to explore further interactions.

To resolve the issue with raytrace and ensure sufficient multipath propagation for a LEO satellite at 400 km altitude, you may need to either adjust the parameters beyond their default limits or employ additional techniques to enhance ray density and interaction modeling. If the source code or configuration settings are accessible, modifying them to allow finer angular separations would be a direct approach. Otherwise, implementing custom solutions or hybrid methods might be necessary to achieve the desired multipath profile

0 Comments

Show -2 older commentsHide -2 older comments

Sign in to comment.

Sign in to answer this question.

See Also

Categories

AerospaceAerospace BlocksetReference Applications

Find more on Reference Applications in Help Center and File Exchange

Tags

  • raytrace
  • ray
  • tracing
  • leo
  • multipath
  • reflection
  • matlab
  • satellite

Products

  • MATLAB

Release

R2024a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

An Error Occurred

Unable to complete the action because of changes made to the page. Reload the page to see its updated state.


'raytrace' function for LEO satellites (3)

Select a Web Site

Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .

You can also select a web site from the following list

Americas

  • América Latina (Español)
  • Canada (English)
  • United States (English)

Europe

  • Belgium (English)
  • Denmark (English)
  • Deutschland (Deutsch)
  • España (Español)
  • Finland (English)
  • France (Français)
  • Ireland (English)
  • Italia (Italiano)
  • Luxembourg (English)
  • Netherlands (English)
  • Norway (English)
  • Österreich (Deutsch)
  • Portugal (English)
  • Sweden (English)
  • Switzerland
    • Deutsch
    • English
    • Français
  • United Kingdom(English)

Asia Pacific

  • Australia (English)
  • India (English)
  • New Zealand (English)
  • 中国
  • 日本Japanese (日本語)
  • 한국Korean (한국어)

Contact your local office

'raytrace' function for LEO satellites (2024)

FAQs

What are the features of LEO satellite? ›

A low earth orbit (LEO) satellite is an object, generally a piece of electronic equipment, that circles around the earth at lower altitudes than geosynchronous satellites. LEO satellites orbit between 2,000 and 200 kilometers above the earth.

What are the disadvantages of LEO satellites? ›

Disadvantages: LEO satellites face challenges such as material degradation, stability, and damage from space debris. Advantages: Larger coverage area, lower latency. Disadvantages: Continuous adjustment of communication links, unique routing challenges.

What is LEO's satellite constellation? ›

Low-Earth Orbit (LEO). Satellites in LEO have altitudes of about 300 km to 2,000 km. For example, the International Space Station orbits at about 400 km, and Iridium, a satellite phone provider, orbits its satellites at about 780 km. For comparison, commercial passenger aircraft fly at an altitude of about 10 km.

What is the use case of LEO satellite? ›

One of the most impactful use cases for combining LEO satellites with 5G is in providing internet access to rural and remote areas. While 5G networks offer high-speed connectivity, their rollout is often limited to urban and suburban areas due to infrastructure costs.

What are the most noticeable features of a LEO? ›

This fixed sign is known for its ambition and determination, but above all, Leos are celebrated for their remarkable bravery. In tarot, Leo is represented by the “strength” card, which depicts the divine expression of physical, mental, and emotional fortitude.

Why are LEO satellites better than GEO? ›

In fact, GEO satellites only cover about 42% of the Earth's surface. Globalstar's LEO devices can typically see and communicate with multiple satellites at the same time, from multiple angles, making the communication more robust.

What is special about the Leo constellation? ›

Unlike some of the other constellations, Leo is recognizable as it actually looks like its namesake composed of a "head" and "mane" shaped sickle, or backward question mark, of stars, and haunches composed of a triad of stars.

How do LEO satellites stay in orbit? ›

The majority of satellites are to be found in LEO, as is the International Space Station (ISS). In order to remain in this orbit, a satellite has to travel at around 17,500 miles per hour (7.8 kilometers per second), at which speed it takes around 90 minutes to complete an orbit of the planet.

What is the purpose of satellite constellation? ›

A satellite constellation is a group of artificial satellites working together as a system. Unlike a single satellite, a constellation can provide permanent global or near-global coverage, such that at any time everywhere on Earth at least one satellite is visible.

What are the risks of LEO satellites? ›

Far more inactive satellites in LEO orbit could pose a greater risk to collisions and access to further orbits for spacecraft attempting to pass them. The impact of a scenario like this is uncertain, but Kostek says that work to understand and mitigate the risk is required now.

How does LEO work? ›

They work in interconnected constellations, forming a network that provides global coverage. LEO satellites communicate with ground-based stations to transmit and receive data, enabling various applications such as global communications, Earth observation, and navigation.

Can you see LEO satellites? ›

LEO satellites orbit 160 t0 2000 kilometers from Earth. Their orbital period is only about 90 minutes. That means that they are visible only for 5 to 20 minutes per orbit.

What are the special features of the LEO constellation? ›

Unlike some of the other constellations, Leo is recognizable as it actually looks like its namesake composed of a "head" and "mane" shaped sickle, or backward question mark, of stars, and haunches composed of a triad of stars.

What are the key features of a satellite? ›

Housing: Constructed from strong materials that can withstand the harsh space environment. Power: Most satellites rely on a solar array to convert sunlight into energy. Thermal Control: Guards satellite equipment against extreme changes in temperature.

Can you see LEO satellites from Earth? ›

LEO satellites orbit 160 t0 2000 kilometers from Earth. Their orbital period is only about 90 minutes. That means that they are visible only for 5 to 20 minutes per orbit.

How long can you see a LEO satellite? ›

A typical LEO satellite orbits the earth in less than two hours, which means that a satellite is in view for only a few minutes.

References

Top Articles
Latest Posts
Recommended Articles
Article information

Author: Geoffrey Lueilwitz

Last Updated:

Views: 6222

Rating: 5 / 5 (80 voted)

Reviews: 87% of readers found this page helpful

Author information

Name: Geoffrey Lueilwitz

Birthday: 1997-03-23

Address: 74183 Thomas Course, Port Micheal, OK 55446-1529

Phone: +13408645881558

Job: Global Representative

Hobby: Sailing, Vehicle restoration, Rowing, Ghost hunting, Scrapbooking, Rugby, Board sports

Introduction: My name is Geoffrey Lueilwitz, I am a zealous, encouraging, sparkling, enchanting, graceful, faithful, nice person who loves writing and wants to share my knowledge and understanding with you.