Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Tracking in satellite communications

Status
Not open for further replies.

senmeis

Full Member level 2
Joined
Nov 26, 2014
Messages
131
Helped
0
Reputation
0
Reaction score
0
Trophy points
16
Activity points
985
Hi,

In satellite communications there is a term called “autotracking antennas”.

My question is, is this tracking capability achieved only by antennas?

From other sources the feed also plays a role in tracking: “We manufacture autotracking feeds with multiple configurations in L-Band, S-Band, and C-Band.”.

And a technique “conical scan” can also be used for tracking which is obviously software based.

Senmeis
 

ktr

Full Member level 3
Joined
Jun 11, 2018
Messages
164
Helped
17
Reputation
34
Reaction score
16
Trophy points
18
Location
Ireland
Activity points
1,438
Tracking and detection are problems of Digital Signal Processing. Tracking cabability changes from platform to platform, if we are talking about drones that may be a gimbal for a directional antenna to stay in line with another one(hence Auto-tracking Antenna) or a DSP algorithm which may control the front-end RF cards, say power output of a satellite, defined by the programmer.
 

senmeis

Full Member level 2
Joined
Nov 26, 2014
Messages
131
Helped
0
Reputation
0
Reaction score
0
Trophy points
16
Activity points
985
But how to intepretate the description “We manufacture autotracking feeds …” if DSP is in charge of autotracking?

Senmeis
 

FvM

Super Moderator
Staff member
Joined
Jan 22, 2008
Messages
49,143
Helped
14,384
Reputation
29,032
Reaction score
13,139
Trophy points
1,393
Location
Bochum, Germany
Activity points
283,247
You know how a satellite antenna is aligned manually with the help of a RF level monitor looped-in the cable after the LNB.

I would expect that an auto-tracking mechanism can similarly use a level detector and incrementally move the antenna servo drive using a perturb and observe algorithm, e.g. performing the mentioned conical scan.
 

anilkrpandey

Member level 5
Joined
Nov 4, 2016
Messages
82
Helped
19
Reputation
38
Reaction score
19
Trophy points
18
Location
Gurgaon
Activity points
980
Special Antenna feed system is design for satellite autotracking. The antenna of the satellite must be pointed accurately toward the earth station antenna with which the satellite is in communication using a high-gain reflector antenna system. In order to achieve this accurate pointing, satellite antenna commonly employ tracking systems to provide signals indicative of the pointing errors in elevation and azimuth relative to the antenna beam of the earth station antenna. In a tracking system, three signals are used for the pointing accuracy of the satellite antenna. These three tracking signals are the azimuth difference signal, elevation difference signal, and the sum signal. The phase and amplitude characteristics of these three signals are utilized in a conventional manner to generate elevation angle error and azimuth angle error signals to control the pointing direction of the satellite antenna.

https://anilkrpandey.wordpress.com/...-and-converter-for-monopulse-tracking-system/
 

ktr

Full Member level 3
Joined
Jun 11, 2018
Messages
164
Helped
17
Reputation
34
Reaction score
16
Trophy points
18
Location
Ireland
Activity points
1,438
But how to intepretate the description “We manufacture autotracking feeds …” if DSP is in charge of autotracking?

Senmeis

I think they manufacture the passive parts and antennas, then they do DSP on the received signal; and using SPI controlled parts they control the movement of antenna with a mechanical unit. Its a complex thing.

DSP is only in charge of computation, you also need proper passive components for receving of signal, and a mechanical unit to move the antenna. Hence they say that they are manufacturing it...
 

senmeis

Full Member level 2
Joined
Nov 26, 2014
Messages
131
Helped
0
Reputation
0
Reaction score
0
Trophy points
16
Activity points
985
The technology you described is called “Four Horn Monopulse” in radar tracking. Obviously is operates in RF domain. In radar mono pulses are required. Can this be satisfied in communications?

Senmeis
 

jesuschrist

Member level 4
Joined
Feb 9, 2017
Messages
79
Helped
9
Reputation
18
Reaction score
8
Trophy points
8
Activity points
566
AUtotracking antennas employ feeds called multimode tracking feeds. There are few versions of it.Some use 4 horn antennas and use the sum and difference of signal levels, Some use TM01 mode for tracking and some use TE21 mode for tracking. These kind of feeds use the amplitude and phase difference of secondary mode(TM01 and TE21) signals. They are made bigger on purpose to allow these higher modes to propagate.Also they employ Phase shifters and DSP to minimize/maximize errors to be able to track a satellite. They are generally used for LEO communication systems.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top