Environmental measuring device

An environmental measuring device comprising:

• a sound wave transceiver unit configured to
• transmit detection sound waves toward a target space, and
• receive detection sound waves;
• a setter configured to
• divide the target space into a plurality of sections, and
• set a first virtual mesh including sections of the plurality of sections divided;
• and
• an estimator configured to estimate a temperature distribution or an airflow distribution in the target space, based on a time of flight of the detection sound waves passing through a predetermined section of the first virtual mesh,
• the estimator being configured to estimate a temperature or an airflow in each of the sections of the first virtual mesh, using a predetermined prediction method and a constraint condition in addition to the predetermined prediction method, and
• the constraint condition including at least one of
• a value representing a temperature or an airflow in a second virtual mesh having a smaller number of sections than the first virtual mesh,
• an amount of the air flowing into and out of at least one of the sections of the first virtual mesh, and
• at least one measured temperature value in the first virtual mesh.