Waa maxay maqalka fog?
Aragtida fog waa helitaanka macluumaadka ku saabsan shay ama dhacdo iyada oo aan la sameyn taabasho jir ahaaneed shayga, taas oo ka soo horjeedda in situ ama goob-joogga. Ereygan waxaa loo adeegsadaa gaar ahaan helitaanka macluumaadka ku saabsan dhulka iyo meerayaasha kale. Aragtida fog waxaa loo adeegsadaa meelo badan, oo ay ku jiraan geophysics, juqraafi, sahaminta dhulka iyo inta badan cilmiga cilmiga dhulka (tusaale ahaan sahaminta geophysics, hydrology, ecology, meteorology, oceanography, glaciology, geology); waxay sidoo kale leedahay militariga, sirdoonka, ganacsiga, dhaqaalaha, qorshaynta, iyo codsiyada bani'aadamnimada, iyo kuwa kale.  Isticmaalka hadda, ereyga dareemayaasha fog guud ahaan waxaa loola jeedaa isticmaalka teknoolojiyada dareemayaasha ku saleysan dayax gacmeedka ama diyaaradda si loo ogaado loona kala saaro walxaha ku jira Dhulka. Waxay ka kooban tahay dusha sare iyo jawiga iyo badaha, oo ku saleysan calaamadaha la faafiyo (tusaale ahaan shucaaca elektromagnetic). Waxaa loo qaybin karaa dareemaha fog ee "firfircoon" (marka calaamad ay soo saarto dayax gacmeed ama diyaarad ku socota shayga oo ay ka tarjumeyso dareemaha) iyo dareemaha fog ee "passive" (marka dareemaha uu ka tarjumeeyo iftiinka qorraxda).