dB per kilometer
Note: Depends on frequency of the radio signal, and on the rate at which rain is falling.
Attenuation is a measure of how much loss a signal experiences when it travels down a communication medium( loss as heat, absorbed by communication medium).It is mesured in decibels Attenuation is a term that refers to any reduction in the strength of a signal, when transmitting over a long dinstance. Attenuation occurs with any type of signal, whether digital or analog. It is also called loss of signals, The extent of attenuation is usually expressed in units called decibels (dBs).
Cable attenuation measures the loss of signal strength as it travels through a cable. The formula for cable attenuation (in decibels per unit length) is typically expressed as: [ \text{Attenuation (dB)} = 10 \times \log_{10} \left( \frac{P_{\text{input}}}{P_{\text{output}}} \right) \div L ] where ( P_{\text{input}} ) is the input power, ( P_{\text{output}} ) is the output power, and ( L ) is the length of the cable in the same units as the power measurements. This formula quantifies how much signal is lost over a given length of cable.
Directions are expressed as units of
The surface area of a shape is expressed in square units.
Here are some international units of measurement:Mass is expressed in kilograms.Length and distance is expressed in meters.Time is expressed in seconds.Electrical current is expressed in amperes.Speed is expressed in meters/second.
The units of probability density are typically expressed as the reciprocal of the units of the variable being measured. For example, if the variable is measured in meters, the units of probability density would be expressed as 1/meters.
The concentration of the solution is expressed in micromolar units.
-- The distance that light travels in some amount of time is expressed in units of distance. -- The time that it takes light to cover some amount of distance is expressed in units of time. -- The speed of light is expressed in units of speed . . . distance/time
Mass is not expressed in kilometers (km). That is a measure of distance. Mass is expressed in units of kilograms (kg)
Assuming you mean "phase", it is usually expressed in angular units - degrees, or radians.
Kinetic energy is typically expressed in units of joules (J) in the International System of Units (SI). However, it can also be expressed in electronvolts (eV) in the field of particle physics.
Mass is expressed in grams in the SI system and slugs in the English system. (these are the base units obviously multiples of these units exist. ex: kg). Volume is expressed as a cubic of any unit of length ex: M^3.