Sparklies is a formal term, as used by British Sky Broadcasting

British Sky Broadcasting

British Sky Broadcasting Group plc is a satellite broadcasting, broadband and telephony services company headquartered in London, United Kingdom, with operations in the United Kingdom and the Ireland....

 (BSkyB) and a number of hardware makers including Amstrad

Amstrad

Amstrad is a British electronics company, now wholly owned by BSkyB. As of 2006, Amstrad's main business is manufacturing Sky Digital interactive boxes....

 and Pace

Pace

Pace may refer to:*Pace , the speed at which movement occurs*Pace , a unit of length*"Peace" in Italian, sometimes written on a rainbow flag...

, for interference on analogue

Analog television

Analog television is the analog transmission that involves the broadcasting of encoded analog audio and analog video signal: one in which the message conveyed by the broadcast signal is a function of deliberate variations in the amplitude and/or frequency of the signal...

 satellite television

Satellite television

Satellite television is television programming delivered by the means of communications satellite and received by an outdoor antenna, usually a parabolic mirror generally referred to as a satellite dish, and as far as household usage is concerned, a satellite receiver either in the form of an...

 transmissions.

Sparklies are black or white 'hard' interference dots (as opposed to the 'soft' interference patterns of terrestrial television

Terrestrial television

Terrestrial television is a mode of television broadcasting which does not involve satellite transmission or cables — typically using radio waves through transmitting and receiving antennas or television antenna aerials...

), caused either by too weak or too strong a signal. When within the satellite's rated reception footprint

Footprint (satellite)

The footprint of a communications satellite is the ground area that its transponders offer coverage, and determines the satellite dish diameter required to receive each transponder's signal...

, sparklies are most likely to be caused by a misaligned dish, or LNB

Low-noise block converter

A low-noise block downconverter is the receiving device of a parabolic satellite dish antenna of the type commonly used for satellite TV reception...

s which are too high- or too low-gain

Gain

In electronics, gain is a measure of the ability of a circuit to increase the power or amplitude of a signal from the input to the output. It is usually defined as the mean ratio of the signal output of a system to the signal input of the same system. It may also be defined on a logarithmic scale,...

 for the dish and receiver.

Sparklies do not occur on digital

Digital television

Digital television is the transmission of audio and video by digital signals, in contrast to the analog signals used by analog TV...

 satellite systems; similar problems with digital signals cause MPEG artifacts

Artifact (error)

In natural science and signal processing, an artifact is any error in the perception or representation of any visual or aural information introduced by the involved equipment or technique....

.