<p>There's an equation for working out the curvature of the earth, and how far you can see depending on your altitude. There's a calculator here: <a href="https://www.omnicalculator.com/physics/earth-curvature" rel="nofollow noreferrer">https://www.omnicalculator.com/physics/earth-curvature</a></p>
<p>There's no single figure for range and height. As you go further, you need to be higher to stay in contact. It says that at 250m altitude, you should be able to see 56km</p>
<p>Of course, that assumes that there aren't any trees or buildings blocking your view of the horizon. Also your signal will be attenuated just by passing close to the ground for a long distance. It really helps if you're also high up.</p>
<p>Really long range requires relaying the signal via a high-flying aircraft or satellite, or via a cellular network.</p>

CC BY-SA 4.0
2024-01-19T19:39:07.350Z
Hey @Robin! Thanks for your response!
9friday
CC BY-SA 4.0
2024-01-19T09:20:41.030Z
2024-01-19T09:20:41.030Z
Robin Bennett
<p>I would like to purchase an HM30 for my drone and would like to clear up a few questions before doing so.</p>
<ol>
<li>Does the network connectivity allow complete birectional access, i.e., air unit &lt;-&gt; ground unit? SIYI's MK15 allows SSHing/ PINGing devices connected to the air unit from the ground, but NOT the other way around.</li>
<li>What is the best possible range and height achievable in real world usage, assuming good weather etc. with the default(bundled)     antennae? Is 30 km range realistically achievable?</li>
<li>What is the lowest height at which the drone can fly without
connectivity issues, since, Earth's curvature comes into play over
long distances?</li>
<li>What is the best possible range if the drone is at a height of 250 m
and 500 m ?</li>
</ol>
<p>Thank you for taking an interest in my query.</p>
<p>Regards. :)</p>

<video-transmitters><long-range-drone>
SIYI HM30: Network Connectivity and Range
9friday
# SIYI HM30: Network Connectivity and Range

(Asked by: username_0 on 2024-01-18)

I would like to purchase an HM30 for my drone and would like to clear up a few questions before doing so.

1. Does the network connectivity allow complete birectional access, i.e., air unit <-> ground unit? SIYI's MK15 allows SSHing/ PINGing devices connected to the air unit from the ground, but NOT the other way around.
2. What is the best possible range and height achievable in real world usage, assuming good weather etc. with the default(bundled) antennae? Is 30 km range realistically achievable?
3. What is the lowest height at which the drone can fly without
   connectivity issues, since, Earth's curvature comes into play over
   long distances?
4. What is the best possible range if the drone is at a height of 250 m
   and 500 m ?

Thank you for taking an interest in my query.

Regards. :)

**Tags:** video-transmitters, long-range-drone


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## 1 answers

### Answer by username_1 on 2024-01-19. Score: 2

There's an equation for working out the curvature of the earth, and how far you can see depending on your altitude. There's a calculator here: <https://www.omnicalculator.com/physics/earth-curvature>

There's no single figure for range and height. As you go further, you need to be higher to stay in contact. It says that at 250m altitude, you should be able to see 56km

Of course, that assumes that there aren't any trees or buildings blocking your view of the horizon. Also your signal will be attenuated just by passing close to the ground for a long distance. It really helps if you're also high up.

Really long range requires relaying the signal via a high-flying aircraft or satellite, or via a cellular network.

> **Comments:**
> **username_0**: Hey @username_1! Thanks for your response!  

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