Assessment of crop productivity IRS satellites capture data that helps assess crop health, growth stage, and potential yield. Locating groundwater resources Remote sensing allows for studying geological features and identifying potential zones with underground water reserves. Mineral exploration IRS data can reveal signatures of specific minerals on the Earth's surface, aiding in mineral exploration activities.

Telecommunications IRS satellites are not designed for telecommunication purposes. Geostationary satellites are typically used for this function. Traffic studies While remote sensing can be used for some traffic studies (e.g., analyzing transportation infrastructure), it's not the primary application of IRS satellites.

Therefore, only 1,2 and 3 are primary applications of IRS satellites.