How to start satellite telecast?

[RETGT]

Hello,
How to start satellite TV telecast in tv?
where to start?
which camera and how how frequency is buyed?

 

[betwixt]

Take small steps RETGT.

What you are asking is extremely complicated. The camera has almost nothing to do with it, you need mixing, video processing, video encoding and an uplink transmitter - and that is just to get a signal to a satellite. Assuming you don't have a satellite of your own, you then need an account with a satellite company and to rent space on a transponder channel. Think in terms of tens of rupee per minute of transmission time!

It's something big companies do, not to try at home!

Brian.

 

[RETGT]

ok i am practicing your experiment of hydrogen and helium balloon in sky
i want to connect a camera with it which can shot from km up to earth surface.

 

[betwixt]

That isn't satellite telecasting!

Get yourself a small 'video sender', the kind of thing that lets you watch video from one room to another, hook up an antenna, batteries and a camera then watch it on a normal TV. Bear in mind it may travel many Km before landing so it may not be retrievable and also that a crash landing from several Km up will almost certainly destroy it.

The trick to getting long range is to use good antennas, particularly at the ground (TV) end. You will have to track it as it drifts in the wind so a steerable Yagi antenna would be a good choice.

Brian.

 

[BradtheRad]

Lots of radio-control pilots shoot videos from their planes/ helicopters/ drones. Some of them no doubt transmit to a ground receiver. An internet search will find information about the requirements of the equipment, maximum distance of transmitting, etc.

 

[RETGT]

Hello,
first i will try normal balloon without camera
does you have any video?
and what will be the maximum height does the ballon will go?
will it reach the airplane height or satellite?

 

[BradtheRad]

Yes, a weather-type balloon can rise to an altitude where airplanes fly. You need to find out about local regulations which govern aviation and airspace. In particular you should not launch a balloon close to an airport. You may need permission to launch, and the authorities may or may not give you permission, depending.

Film clips I've seen show a weather balloon partially inflated at launch. It expands as it reaches rarefied air.

It's a good idea to tether the balloon. Then it's easy to bring back, and you don't lose it.

 

[RETGT]

hello,
The airport is very far .
Can we build detect plane from home like radars?

 

[betwixt]

It's a good idea to tether the balloon. Then it's easy to bring back, and you don't lose it.

From 120,000 feet! Thats an awfully long tether

My video of the experiments is on VHS tape so it will take a while to extract some still shots from it.

No, you can't run radar from home. Quite apart from the technical difficulties of a large fast moving dish, you need a pulsed high power transmitter (several KW), a fast T/R switch and a sensitive microwave receiver. After that you need the system to scale and vectorize the echo to see a meaningful display.

If you want to track aircraft, an ACARS receiver is a better option and that certainly IS doable at home. I can see aircraft and track their positions within a radius of about 100Km from here.

Brian.

 

[RETGT]

My video of the experiments is on VHS tape so it will take a while to extract some still shots from it.

What we can learn from balloon in sky sir?

- - - Updated - - -

hello sir,
What is this?
ACARS

 

[betwixt]

I found some clips of my video on Youtube. Search for "WB8ELK" and look at the "Illinois" video from 1989. The full recording is 4 hours long!

ACARS = Aircraft Communication Addressing and Reporting System.
It is a radio information system using VHF that lets airports exchange information with aircraft automatically. Most larger aircraft also send a transmission on a timer which gives their latitude/longitude and altitude. It often carries other messages about remaining fuel and special needs at the destination airport. Many of the messages are just numbers, they mean something to a computer somewhere but are not human readable.

There is a similar sytem called HFDL (High Frequency Data Link) which paradoxically uses lower frequencies than ACARS, this was picked up a few minutes ago on 8.942MHz:

<300 bps 1.8 sec 1453 Hz> 31/12/2016 10:42:52
MPDU CRC control: OK
MPDU (Media access control Protocol Data Unit) - Downlink
00 Ground Station Identifier: 7 - Shannon, IRELAND (008-55-46W 52-43-48N) Not synchronized to UTC time
01 Aircraft Identifier: 255
02 Number of medium priority slots: 0 Low priority slots: 1
03 Uplink data rate: 1200 bits/s U(R): 0 LPDU [ U(R) Vect + 1..8 ]: 00000000
04 Number of LPDU: 1 LPDU Sizes: 57
LPDU CRC control: OK
[LPDU log-on request resume] Aircraft ICAO address (hex): 8A01D3

It is a downlink from an aircraft to Shannon air control in Ireland.

Brian.

 

[RETGT]

https://www.google.co.in/?gfe_rd=cr&ei=XY1nWPrjLc-9hAbPh43QCw&gws_rd=ssl#q=wb8elk+Illinois+youtube

this?
and how you pick and why?

 

[betwixt]

https://www.youtube.com/watch?v=GJ0f0Hy5ZH8
is the shortened video clip. It was posted by the person who did the original launch, I met him a few days later at a meeting in Indianapolis, Indiana in the USA. I have a version I made using my own video camera but it isn't on the Internet.

Brian.

 

[RETGT]

yes i seen that video .
what you get information from it?

 

[c_mitra]

first i will try normal balloon without camera

You need to devote some time to thinking. Balloons can reach heights greater than a common passenger plane (about 10 km) but the atmosphere is thin at that altitude and such balloons are expensive (not to mention about the amount of He gas you will need). And they cannot reach the heights of satellites. They need to be tracked and you will need permission from various agencies to fly such a device. Low height balloons are not a problem if they are not close to airports or on the approach path (flights). Still, they are not cheap.

 

[RETGT]

how to track balloon?
in my city there is no problem.

 

[betwixt]

how to track balloon?
in my city there is no problem.

It has a transmitter on board to send the picture/data to you on the ground. You use a directional antenna and keep it moving (you may have to be mobile yourself) to pick up the strongest signal, that is the direction the balloon is in. It helps to know the wind direction and speed, it could travel many Km before landing so knowing the direction the wind will take it gives you an idea of likely landing places. Remember that if it travels more than a few Km, the signal will become weak and if it goes over the horizon, especially at low altitude, you could lose the signal completely and never find it again!

Double check with local authorities wheteher you are allowed to launch a balloon. They are big things and can be a hazard to aircraft. As they rise and the air pressure drops, they get bigger and bigger. At ground level they may only be 2m diameter but at high altitude they can be 20m or more!

Brian.

 

[RETGT]

hello,
which transmitter to use?
and what is directional antenna i have never used?
in my place there are no aeroplanes.

 

[zainka]

A few things about tracking. Knowing the wind speed and direction is important, but it is not enough to know this at ground. The speed and direction will change several times as the balloon rises up up and away due to the atmospheres many layers. Check with your national weather data provider (or airports) for where to get such data for high altitudes.

Where are you located? Close to the sea or inland? A boat may be necessary if close to sea. At my place the wind direction at high altitudes are often directed towards sea in the morning and towards land at the evening, so choosing the time for when to launch the balloon may become important.

Adding a separated beacon module for tracking could be wise. i.e. A dedicated low frequency, long range, rf transmitter, AM modulated with a sputnik like "bliip" makes RF tracking more easily. You should try that before sending up any balloons with expensive camera electronics.

A directional antenna, like the Yagi antenna, has better reception in one axis of the antenna. By googeling the Yagi antenna you will understand that the best reception is along the axis of the longest part of the antenna (sorry for my English). An omnidirectional antenna receives/transmitts signals from "any" directions. For TV you normally know where the transmitter is located and you use an directional antenna like the yagi pointed in the transmitters position to get the best possible signal without picking up noise and unwanted signals from other transmitters. A car radio on the other hand, moves and needs an antenna that can receive signals from any direction and thus uses a wipe-antenna or "half-pole antenna", or as in one of my first car radio I ever had, just a piece of wire.

https://upload.wikimedia.org/wikipe..._Antenna_001.JPG/330px-UHF_TV_Antenna_001.JPG
Example of Yagi antenna (or actually an yagi-uda antenna. The inventors name)


The transmitter antenna in the balloon "must" be omnidirectional (there is other solutions but even professionals uses these as its simple and do the job), i.e. it transmits its energy in every direction because the balloon will rotate and the antenna will rotate with it and won't be pointing the same side towards your position all the time. On ground you should have directional antennas which you must point directly towards the object. One for tracking and one for receiving TV signals. But, if using directional antennas, you must either have a system for moving the antenna so that it always points in the ballons position or you need to do it manually based on the feedback you hear when demodulating the AM signal (Use a frequency which can be received by commercial radio receivers) or what you see on the TV receiver.

You could also use omnidirectional antennas for receiving the TV signals as you then don't need to control the antennas position, making things far more simpler, but they are not as sensible as directional antennas and you may need to use a more powerful transmitter at the balloon to be able to receive a decent quality signal at the receiver antenna, eating battery. For tracking you still need directional antennas (Actually, you could also use several omnidirectional antennas for tracking and based on the tracking signals propagation delay for when it reaches the different antennas on could use clever maths to calculate the position of the balloon. But that is a different story)

Funny project though, good luck.

 

[RETGT]

Hello,
the threat will also rise with ballon.