Terahertz spectroscopy and imaging in dynamic environments with spectral response enhancements

A system comprising:

• a transmitter configured to emit a continuous electromagnetic (EM) wave in a terahertz (THz) frequency band into a dynamic environment, the dynamic environment including a transmission medium that changes over time;
• a receiver configured to receive a reflected EM wave from at least one object in the environment;
• one or more processors;
• memory storing instructions that when executed by the one or more processors, cause the one or more processors to perform operations comprising:
• determining a spectral response of a received signal indicative of the reflected EM wave, the spectral response including absorption spectra at a frequency in the THz frequency band that is indicative of the transmission medium in the environment;
• compensating the spectral response of the received signal for fixed and frequency-specific losses,
• wherein compensating for frequency-specific losses includes:
• determining an average signal strength of peaks in the spectral response of the received signal;
• and
• subtracting the average signal strength from the spectral response of the received signal;
• comparing the compensated respectal response with known spectral responses of target transmission mediums;
• identifying a particular target transmission medium as being the transmission medium in the environment based on results of the comparing;
• determining an absorption loss from the absorption spectra in the spectral response of the received signal;
• and
• using the absorption loss to obtain a concentration level of the target transmission medium in the environment.

A non-transitory, computer-readable storage medium having stored thereon instructions that when executed by one or more processors, cause the one or more processors to perform operations, comprising:

• emitting a continuous electromagnetic (EM) wave in a terahertz (THz) frequency band, the EM wave being emitted into a dynamic environment that includes a transmission medium that changes over time;
• receiving a reflected EM wave reflected off at least one object in the environment;
• determining a spectral response of a received signal indicative of the reflected EM wave, the spectral response including absorption spectra at a frequency in the THz frequency band that is indicative of the transmission medium in the environment;
• compensating the spectral response of the received signal for fixed and frequency-specific losses,
• wherein compensating for frequency-specific losses includes determining an average signal strength of peaks in the spectral response of the received signal, and subtracting the average signal strength from the spectral response of the received signal;
• comparing the compensated spectral response with known spectral responses of target transmission mediums;
• identifying, based on results of the comparing, a particular target transmission medium as being the transmission medium in the environment;
• determining an absorption loss from the absorption spectra in the spectral response of the received signal;
• and
• using the absorption loss to obtain a concentration level of the target transmission medium in the environment.