PDA

View Full Version : What is USALS ?



PSB
08-01-2006, 12:08 PM
Universal Satellites Automatic Location System

http://www.usals.info/



"USALS and DisEqC 1.2


In 1997 thanks to EUTELSAT-STAB collaboration, all commands of the DisEqC 1.2 standard were developed to operate dish motors directly from the receiver via the LNb cable.

The DisEqC 1.2 system has been adopted as a standard by satellite receiver manufacturers. It needs several adjustments to achieve correct dish alignment including correct southern alignment, manual setting of all satellite positions, limit settings etc.

Since 1999, the main aim of STAB research has been to solve the problems associated with the dish motor installation and to enable end users to buy STAB motors from their retailer and install them easily, anywhere in the world. The new USALS program has enabled this goal to be reached.

USALS is a calculation system processed by STAB of Italy and given free to all manufacturers of satellite receivers and PC cards. The program enables the receiver to calculate the positions of all satellites in orbit with a precision of better than 0.1 degrees with reference to the installation site. This is achieved automatically without the need for specialised technical knowledge.

Please remember that USALS is a program and not a communication protocol. In collaboration with EUTELSAT, the DisEqC 1.2 protocol string has been defined to drive the motors in "Drive Motor to Angular Position (degree)" mode, which is the only command itilised by the USALS program. The USALS program is, therefore, an advanced option of the DisEqC 1.2 protocol.

How to determine whether a receiver complies with the USALS standard?
STAB authorises each manufacturer to use the USALS program ONLY after testing in the laboratory. The receive must have the following:

1. The "STAB-USALS" logo printed on its box.
2. The USALS option under "Motor Setting" in the on-screen menu.
Any other description such as "Go X", "Go To XX'", "DisEqC1.3" have not been authorised by STAB so the correct working of the program can not be guaranteed.

Advantages of USALS
If the dish is not initially aligned perfectly to face due south (in the Northern hemisphere) then the search for satellites is normallt problematic. However, with USALS, this inconvenience no longer exists because the program calculates the positions of all "visible" satellites, on the basis of latitude and longitude of the installation site, with a precision of +/- 0.05 degrees. This is possible because the USALS program also decides the direction of rotation.

With DisEqC1.2 a manual search and memorisation of every satellite position is required. However, with USALS all you have to do is point the dish towards a satellite at the centre of the arc and USALD will automatically find and store the rest.

With DisEqC1.2, the user is obliged to seek the help of an expert every time a satellite position has been changed or a new one activated. However, with USALS, you need only to add the name of the new satellite to the list, and its orbital position. The motor will move to the new position without need for further programming or alignment!

As the user doesn't need to carry out complicated adjustments or programming, the risk of making a mistake is greatly reduced. This is unlike standard DisEqC1.2 where a small error can require the installation procedure to be started from the beginning."

Reigster at SatelliteGuys