Ebyte E32-433T30D SX1278 LoRa range calculation using a 3.6dbm OmniDirectional antenna

Thread Starter

Solanum Asteridion

Joined Sep 5, 2023
36
Hi guys so i was testing out the range of this mode using an online clac, I am getting 2600km range?!
1693901895019.png

And also if the antenna will be mounted on a satellite, how will I communicate with it?
 
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Janis59

Joined Aug 21, 2017
1,813
You calculated correctly. If calc the mobile phone distance, it comes between 2 and 20 MILLION kilometers. And it will certainly be true as we know from GPS systems success staying at 19 000 km distance.
Whole the contradiction to everyday experience is NOT because of signal / noise ratio or signal weakness, but because of signal complete NON-EXISTANCE. Where it was lost You may ask. Here is the short answer - in the Planet curvature.

Right way of calc is to evaluate the distance from transmitter antenna to path contact with Earth surface L1=3.57*SQRT(H), where L is km, but antenna active part heigth over land H is meters. Then make the identical calculus for receiving antenna and add L(max)=L1+L2. In no respect how good the antenna G factor, but if antenna hangs too low - the signal over the L(max) is definite null.
 
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Ya’akov

Joined Jan 27, 2019
8,954
Welcome to AAC.

The gain figure of the antenna is based on its radiation pattern. If you are using an antenna on a space vehicle to communicate with earth stations you have to have a directional antenna you can point down, towards the earth. An omnidirectional gain antenna just compresses the signal to some part of the antenna to optimize how it is used.

Normally, this will be from the top or center, with the weakest radiation facing up and down. Great for line of site earth station to earth station links but exactly what you don’t want for space communications.
 

Thread Starter

Solanum Asteridion

Joined Sep 5, 2023
36
You calculated correctly. If calc the mobile phone distance, it comes between 2 and 20 MILLION kilometers. And it will certainly be true as we know from GPS systems success staying at 19 000 km distance.
Whole the contradiction to everyday experience is NOT because of signal / noise ratio or signal weakness, but because of signal complete NON-EXISTANCE. Where it was lost You may ask. Here is the short answer - in the Planet curvature.

Right way of calc is to evaluate the distance from transmitter antenna to path contact with Earth surface L1=3.57*SQRT(H), where L is km, but antenna active part heigth over land H is meters. Then make the identical calculus for receiving antenna and add L(max)=L1+L2. In no respect how good the antenna G factor, but if antenna hangs too low - the signal over the L(max) is definite null.
So, with an antenna height (H) of 200 kms, the maximum calculated distance (Lmax) between the transmitter antenna and the Earth's surface is approximately 50.60 kilometers?
 

Thread Starter

Solanum Asteridion

Joined Sep 5, 2023
36
Welcome to AAC.

The gain figure of the antenna is based on its radiation pattern. If you are using an antenna on a space vehicle to communicate with earth stations you have to have a directional antenna you can point down, towards the earth. An omnidirectional gain antenna just compresses the signal to some part of the antenna to optimize how it is used.

Normally, this will be from the top or center, with the weakest radiation facing up and down. Great for line of site earth station to earth station links but exactly what you don’t want for space communications.
but I do not want to track the satellite, I want to keep receiving signals from it when in is the area where I am located
 

Ya’akov

Joined Jan 27, 2019
8,954
but I do not want to track the satellite, I want to keep receiving signals from it when in is the area where I am located
Why do you think I was talking about tracking? Please explain what the application for this is, I can‘t help you by guessing. What are you planning to have this arrangement do? What satellite are you planning to use?
 

Thread Starter

Solanum Asteridion

Joined Sep 5, 2023
36
Why do you think I was talking about tracking? Please explain what the application for this is, I can‘t help you by guessing. What are you planning to have this arrangement do? What satellite are you planning to use?
I'm planning to build an affordable satellite that will be in Low Earth Orbit. I have chosen the LoRa module that has the largest transmitting power. I want to receive data from it when it is in the portion where I am there (divide the earth into 2 hemispheres, west and east). How do I achieve this? Or maybe I can have a ground stations in the 2 hemispheres. There will be a ground station with the same module and same antenna, and there will be this module on the satellite. Thank you. External Camera Module Design.jpg
 

Thread Starter

Solanum Asteridion

Joined Sep 5, 2023
36
I'm planning to build an affordable satellite that will be in Low Earth Orbit. I have chosen the LoRa module that has the largest transmitting power. I want to receive data from it when it is in the portion where I am there (divide the earth into 2 hemispheres, west and east). How do I achieve this? Or maybe I can have a ground stations in the 2 hemispheres. There will be a ground station with the same module and same antenna, and there will be this module on the satellite. Thank you. View attachment 302202
I am also planning to attach a camera on board that will be sent through LoRa in chunks to form a 2592x1944 image in JPEG.
 

Janis59

Joined Aug 21, 2017
1,813
So, with an antenna height (H) of 200 kms, the maximum calculated distance (Lmax) between the transmitter antenna and the Earth's surface is approximately 50.60 kilometers?
One thing to change - antenna mast is 200 METERs high tower, not kilometers. Yes, the distance for UHF is always small. However, if both, transmitter and receiver are 200 meter high, then 50 km plus 50 km is already 100 km of radio-horizon!! From 200 km You get all the hemisphere beyond it.
By the way, hope You recognize that 200 km have still air enough to decelerate the satellite rather fast. Your project will have a unpleasantly short life-time.
 

Thread Starter

Solanum Asteridion

Joined Sep 5, 2023
36
One thing to change - antenna mast is 200 METERs high tower, not kilometers. Yes, the distance for UHF is always small. However, if both, transmitter and receiver are 200 meter high, then 50 km plus 50 km is already 100 km of radio-horizon!!
My 1 antenna will be on a satellite and the other on the ground.. So what range will i get is the thing I am not understanding. Can you please help?
 

Ya’akov

Joined Jan 27, 2019
8,954
I think you need to talk to people with specific knowledge about satellites. This is not a trivial thing, and you won’t be able to just work it out yourself.

For example, Lacuna had some troubles with their first bird despite having a lot of expertise on their team. There are also regulatory hurdles and transmitting anything from space requires special consideration.

I‘m sorry but I can’t help you with this at all, and there really isn’t anyone here that I know of who is qualified to help. Please seek out genuine expertise, this is not a simple project you can just work out by buying “the most powerful” module or getting advice from random posters on the Internet.
 

Thread Starter

Solanum Asteridion

Joined Sep 5, 2023
36
I think you need to talk to people with specific knowledge about satellites. This is not a trivial thing, and you won’t be able to just work it out yourself.

For example, Lacuna had some troubles with their first bird despite having a lot of expertise on their team. There are also regulatory hurdles and transmitting anything from space requires special consideration.

I‘m sorry but I can’t help you with this at all, and there really isn’t anyone here that I know of who is qualified to help. Please seek out genuine expertise, this is not a simple project you can just work out by buying “the most powerful” module or getting advice from random posters on the Internet.
Ok thank you so much!
 

Ya’akov

Joined Jan 27, 2019
8,954
MODERATION: This thread has been moved to the Homework Help forum according to AAC rules that limit the sort of help members can provide to students doing coursework to guidance with their own attempts to solve the problem.
 

Janis59

Joined Aug 21, 2017
1,813
My 1 antenna will be on a satellite and the other on the ground.. So what range will i get is the thing I am not understanding. Can you please help?
The formula I gave in this case may give the data out of it comfort zone, however I cannot bet the output will be plainly wrong. This case may try to make a small immagination model - 63 meter large ball over what at 0.2 meter distance floats Your satellite. What will be the field of view? Then formula speaks about 1600 km radius or 3200 km diameter of patch You see from above. Inside it the radio will work. Knowing Your intent is real time video stream, the LORA will be very bad format. I expect the Nordic NRF24L will be more suitable, however the 2.4 GHz attenuation on water fog may be rather harsh problem there. But if to go lower frequencies, the speed is lost. Go to higher?? Hmmm. Should be made a fundamental research what frequencies are well going through the ionosphere hanging between 50th and 600th kilometers. Actually that is damn bad place from where to make a radio call. And few people have knowledge what exactly takes a place there high up.
 

Thread Starter

Solanum Asteridion

Joined Sep 5, 2023
36
The formula I gave in this case may give the data out of it comfort zone, however I cannot bet the output will be plainly wrong. This case may try to make a small immagination model - 63 meter large ball over what at 0.2 meter distance floats Your satellite. What will be the field of view? Then formula speaks about 1600 km radius or 3200 km diameter of patch You see from above. Inside it the radio will work. Knowing Your intent is real time video stream, the LORA will be very bad format. I expect the Nordic NRF24L will be more suitable, however the 2.4 GHz attenuation on water fog may be rather harsh problem there. But if to go lower frequencies, the speed is lost. Go to higher?? Hmmm. Should be made a fundamental research what frequencies are well going through the ionosphere hanging between 50th and 600th kilometers. Actually that is damn bad place from where to make a radio call. And few people have knowledge what exactly takes a place there high up.
Thank you so much I will surely check out other devices and frequencies...
 

Janis59

Joined Aug 21, 2017
1,813
I know that 300 km from my seat is situated Ventspils Augstskola (Ventspils Highest School) what have decade long experience with satcubes launching in lower Space, and they specializes in electronics design for those students project. Sure they have a certain proffessor who knows these details about what I am only guessing. Here is the Univeristy official address venta@venta.lv where You may kindly ask to contact the person who knows sth about Low Space CubSat projects. I am sure they in the small rural University are kind persons and will answer readily.
 

Thread Starter

Solanum Asteridion

Joined Sep 5, 2023
36
I know that 300 km from my seat is situated Ventspils Augstskola (Ventspils Highest School) what have decade long experience with satcubes launching in lower Space, and they specializes in electronics design for those students project. Sure they have a certain proffessor who knows these details about what I am only guessing. Here is the Univeristy official address venta@venta.lv where You may kindly ask to contact the person who knows sth about Low Space CubSat projects. I am sure they in the small rural University are kind persons and will answer readily.
thank you so much!
 
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