Spectrogram
Level 2 Category
Definition
Visual representation of signal frequencies over time, displayed as a heat map with time on x-axis, frequency on y-axis, and color showing amplitude
Example Image
Variable Frequency. JPG file, available at https://commons.wikimedia.org/wiki/File:VariableFrequency.jpg. Public domain.
Writing Alternative Text
Describe the variables, the distribution of energy across time and frequency, and any notable bands, peaks, harmonics, or changes in intensity as the signal evolves.
Example Alt Text
"Spectrogram showing an FM signal over 5 seconds. The carrier frequency is 2000 Hz, and the instantaneous frequency oscillates between about 1000 Hz and 3000 Hz. Colors represent signal intensity, from blue for low energy to red for high energy."