The SINPO (or SINFO) Report

SINPO, an acronym for Signal, Interference, Noise, Propagation, and Overall, is a Signal Reporting Code used to describe the quality of broadcast and radiotelegraph transmissions. SINPFEMO, an acronym for Signal, Interference, Noise, Propagation, frequency of Fading, dEpth, Modulation, and Overall is used to describe the quality of radiotelephony transmissions. SINPFEMO code consists of the SINPO code plus the addition of three letters to describe additional features of radiotelephony transmissions. These codes are defined by Recommendation ITU-R Sm.1135, SINPO and SINPFEMO codes.^[1]

SINPO code is most frequently used in reception reports written by shortwave listeners. Each letter of the code stands for a specific factor of the signal, and each item is graded on a 1 to 5 scale (where 1 stands for nearly undetectable/severe/unusable and 5 for excellent/nil/extremely strong).

The code originated with the CCIR (a predecessor to the ITU-R) in 1951, and was widely used by BBC shortwave listeners to submit signal reports, with many going so far as to mail audio recordings to the BBC’s offices.^[2]

SINPO and SINPFEMO are the official signal reporting codes for international civil aviation ^[3] and ITU-R.^[1]

The use of the SINPO code can be subjective and may vary from person to person. Not all shortwave listeners are conversant with the SINPO code and prefer using plain language instead.

SINPO code explained

S (Signal strength)The relative strength of the transmission.
I (Interference)Interference from other stations on the same or adjacent frequencies.
N (Noise)The amount of atmospheric or man-made noise.
P (Propagation)Whether the signal is steady or fades from time to time.
O (Overall merit)An overall score for the listening experience under these conditions.

Rating	S	I	N	P	O
Scale	Signal strength	Interference	Noise	Propagation Disturbance	Overall rating
5	Excellent	Nil	Nil	Nil	Excellent
4	Good	Slight	Slight	Slight	Good
3	Fair	Moderate	Moderate	Moderate	Fair
2	Poor	Severe	Severe	Severe	Poor
1	Barely audible	Extreme	Extreme	Extreme	Unusable

SINPFEMO code

An extension of SINPO code, for use in radiotelephony (voice over radio) communications, SINPFEMO is an acronym for Signal, Interference, Noise, Propagation, frequency of Fading, depth, Modulation, and Overall.

	S	I	N	P	F	E	M	O
Rating Scale	Signal strength	Interference	Noise	Propagation disturbance	Frequency of fading	Quality	Depth	Overall rating
5	Excellent	Nil	Nil	Nil	Nil	Excellent	Maximum	Excellent
4	Good	Slight	Slight	Slight	Slow	Good	Good	Good
3	Fair	Moderate	Moderate	Moderate	Moderate	Fair	Fair	Fair
2	Poor	Severe	Severe	Severe	Fast	Poor	Poor or Nil	Poor
1	Barely audible	Extreme	Extreme	Extreme	Very fast	Very Poor	Continuously over-modulated	Unusable

References[edit]

1. ^ Jump up to:^a b “ITU-R Sm.1135, SINPO and SINPFEMO codes” (PDF).
2. ^ “BBC Engineering Division Monnograph, Number 43: September 1962” (PDF).
3. ^ “Procedures for Air Navigation Services: ICAO Abbreviations and Codes” (PDF). Retrieved 27 April 2015.
4. ^ “Reception Reports: Reporting Code – Writing Useful Reception Reports”. Archived from the original on January 7, 2009. Retrieved 27 April 2015.
5. ^ Berg, Jerome. Early Shortwave Stations.