A system for the real-time spectral width resolution measurement of the atmospheric attenuation spectrum of electromagnetic radiation, characterized in that it comprises: - at least one source of emission of artificial electromagnetic radiation or at least one screen as a source of emission which reflects natural electromagnetic radiation, - at least two reflective telescopes (10, 20) for the capture of a beam of the radiation from only said source which are located at different distances from said source, each telescope (10, 20) comprising a diaphragm between the telescopic objective and the eyepiece to limit the angle of acceptance ( α) of the telescope (10, 20) and avoid the capture of light that comes from outside the radiation source of the system, - at least one system for optical alignment of each telescope with the source, comprising a digital camera to enable displaying the captured image of the source, - at least one photodiode array spectrometer as real time detection and measurement device (23, 24), optically connected to each of the telescopes (10, 20) to provide monochromatic, spectral and total simultaneous measurements of the radiation in the solar spectral range between 300 nm and 1650 nm, - splitting means for splitting the beam of radiation after each eyepiece to take one part of the beam to the at least one array spectrometer (23, 24) and another part of the beam to the sensor of the digital camera of the system for optical alignment of each telescope (10, 20) with the source, and - at least one processor for the communication between the spectrometers (23, 24); for analyzing the aforementioned measurements from the signals detected by the spectrometers (23, 24); as well as for inferring the solar energy attenuation in the distance between the telescopes (10, 20) through the difference, in real-time, of the spectral energy that strikes in said telescopes (10, 20); and for calculating the monochromatic attenuation, spectral attenuation and total attenuation, in said distance between the two telescopes (10, 20): ∘ the monochromatic attenuation being defined as the attenuation at a wavelength of the spectrum with the spectral width provided by the measurement system, ∘ the spectral attenuation being defined as the set of monochromatic attenuations at all the wavelengths throughout the spectral range of measurements,, ∘ and the total attenuation being defined as the attenuation calculated by the integration of the spectral attenuation in the spectral range of measurement weighted with the solar spectrum, and where in the relative atmospheric attenuation spectrum is obtained by comparing the spectral curves obtained from said two real-time detection and measurement devices (23, 24). - at least one source of emission of artificial electromagnetic radiation or at least one screen as a source of emission which reflects natural electromagnetic radiation, - at least two reflective telescopes (10, 20) for the capture of a beam of the radiation from only said source which are located at different distances from said source, each telescope (10, 20) comprising a diaphragm between the telescopic objective and the eyepiece to limit the angle of acceptance ( α) of the telescope (10, 20) and avoid the capture of light that comes from outside the radiation source of the system, - at least one system for optical alignment of each telescope with the source, comprising a digital camera to enable displaying the captured image of the source, - at least one photodiode array spectrometer as real time detection and measurement device (23, 24), optically connected to each of the telescopes (10, 20) to provide monochromatic, spectral and total simultaneous measurements of the radiation in the solar spectral range between 300 nm and 1650 nm, - splitting means for splitting the beam of radiation after each eyepiece to take one part of the beam to the at least one array spectrometer (23, 24) and another part of the beam to the sensor of the digital camera of the system for optical alignment of each telescope (10, 20) with the source, and - at least one processor for the communication between the spectrometers (23, 24); for analyzing the aforementioned measurements from the signals detected by the spectrometers (23, 24); as well as for inferring the solar energy attenuation in the distance between the telescopes (10, 20) through the difference, in real-time, of the spectral energy that strikes in said telescopes (10, 20); and for calculating the monochromatic attenuation, spectral attenuation and total attenuation, in said distance between the two telescopes (10, 20): ∘ the monochromatic attenuation being defined as the attenuation at a wavelength of the spectrum with the spectral width provided by the measurement system, ∘ the spectral attenuation being defined as the set of monochromatic attenuations at all the wavelengths throughout the spectral range of measurements,, ∘ and ∘ the monochromatic attenuation being defined as the attenuation at a wavelength of the spectrum with the spectral width provided by the measurement system, ∘ the spectral attenuation being defined as the set of monochromatic attenuations at all the wavelengths throughout the spectral range of measurements,, ∘ and the total attenuation being defined as the attenuation calculated by the integration of the spectral attenuation in the spectral range of measurement weighted with the solar spectrum, and where in the relative atmospheric attenuation spectrum is obtained by comparing the spectral curves obtained from said two real-time detection and measurement devices (23, 24).