In which of the following activities are Indian Remote Sensing (IRS) satellites used? 1. Assessment of crop productivity 2. Locating groundwater resources 3. Mineral exploration 4. Telecommunications 5. Traffic studies Select the correct answer using the code given below.

1. Indian Remote Sensing (IRS) satellites are a series of Earth observation satellites built, launched, and maintained by ISRO. They provide data in various spectral bands for numerous applications. 2. Statement 1: IRS data (like spectral signatures of crops, vegetation indices) is extensively used for assessment of crop acreage, health, condition monitoring, and yield estimation, thus contributing to crop productivity assessment. Correct. 3. Statement 2: Remote sensing data helps identify geological structures, landforms, vegetation patterns, and soil moisture conditions that indicate potential zones for locating groundwater resources. IRS data is used for this purpose. Correct. 4. Statement 3: Remote sensing techniques, using multispectral and hyperspectral data from satellites like IRS, are employed in mineral exploration by identifying altered rock zones and geological formations associated with mineral deposits. Correct. 5. Statement 4: Telecommunications typically rely on communication satellites (like INSAT/GSAT series), which are usually placed in geostationary orbits. IRS satellites are primarily Earth observation satellites in polar orbits and are not designed for telecommunications services. Incorrect. 6. Statement 5: While satellite imagery can potentially be used for broad traffic analysis or infrastructure planning, detailed, real-time traffic studies usually rely on ground-based sensors, GPS, or aerial surveillance. IRS satellites are generally not the primary tool for operational traffic studies due to resolution and revisit time limitations. Incorrect. 7. Therefore, IRS satellites are primarily used for activities 1, 2, and 3 among the given options.