5.11. Types of Remote Sensing Platforms

Ground based platforms: Such platforms are operational from or near the ground kept near the object under investigation. The studies from the data collected by ground-based platforms are carried out extensively, both at laboratory and in the field. The results greatly help in the development of reflectance pattern and design of sensors for the characterization of Earth surface features, as well as detailed mapping of minute changes, such as cracks, deformations. Terrestrial cameras, handheld cameras, spectro-radiometers, laser based equipment, and GPS are the examples used for laboratory and field experiments to collect information about the Earth features.

Ground-based platforms are tools that operate close to or on the Earth's surface to gather data about specific features. This includes using various devices like cameras and spectroradiometers, which capture light from the objects being studied. The data collected helps improve technologies used in remote sensing, particularly in understanding small changes in the Earth's surface, such as cracks in the ground. These platforms are essential for manual data collection and analysis in both controlled environments (like labs) and natural settings (like fields).

Imagine a scientist studying a tree in a forest. Instead of estimating its health from the sky, they go up close with a camera and special equipment to measure its leaves' reflections. This detailed study helps them understand how the tree responds to its environment, much like how ground-based platforms help us learn about Earth's features more accurately.

Air-borne platforms: These platforms are used to collect the data from a low height above the ground or to test the performance of the sensors before they are actually mounted in the space-borne platforms. These systems cover a larger area than the ground-based methods, and offer speed in data collection. Important airborne platforms include; balloons, aircrafts, drones/Unmanned Aerial Vehicles (UAVs), and laser scanners. Aircrafts and drone offer an economical method of collecting the high resolution ground data. Laser based equipment are also being mounted on aerial platforms to collect the data.

Airborne platforms operate at a height above the ground, which allows them to cover more area quickly than ground-based tools. These platforms, such as drones, helicopters, and airplanes, can collect high-resolution images and data. They are particularly useful for testing sensor performance before sending them into space. This method of data collection is usually faster and can be more cost-effective, allowing for comprehensive surveys of large areas without the extensive time required from ground studies.

Think of a drone as a bird with a camera flying over a city. It can capture images and collect information much faster than someone walking on the ground. Just like the bird could see all the buildings at once, drones gather information over broad areas, helping scientists assess things like land use or crop health efficiently.

Space-borne platforms: These platforms operate at much greater heights, such as Landsat, SPOT and IRS remote sensing satellites, the NOAA series of meteorological satellites, the GOES and INSAT series of geostationary satellites. They carry the sensors which have been tested earlier on previous platforms, and collect the data for a large area in a short time.

Space-borne platforms refer to satellites that orbit the Earth at high altitudes. These satellites are equipped with sensors capable of collecting large volumes of data over vast areas relatively quickly. They rely on technologies tested on ground and airborne platforms before deployment, ensuring reliability and effectiveness in data collection. Space-borne systems are crucial for monitoring global environmental changes, weather patterns, and land use, providing a broad perspective that ground and air platforms cannot achieve.

Imagine being on a tall building and using binoculars to see everything happening in a large park below. The satellite acts like that taller view, capturing broad pictures of the Earth, helping us understand changes over time, like how forests shrink or cities expand, which we can easily miss from just one viewpoint on the ground.

--