Platform: the vehicle carrying the remote-sensing device
Sensor: the remote sensing device recording wavelengths of energy
There are many different types of platforms that can be used for remote sensing and geographic information systems (GIS). Some common platforms include:
- Satellites: These are spacecraft that orbit the Earth and are equipped with sensors to collect imagery and other data. Satellites can provide coverage of large areas at high spatial and spectral resolutions, but they may not be able to collect data as frequently as other platforms.
- Aerial platforms: These include aircraft, such as planes and helicopters, that are equipped with sensors to collect imagery and other data. Aerial platforms can provide high spatial and spectral resolutions and can be used to collect data more frequently than satellites. However, they may not be able to cover as large an area as satellites.
- Unmanned aerial vehicles (UAVs): These are small aircraft, also known as drones, that can be equipped with sensors to collect imagery and other data. UAVs can be used to collect high spatial and spectral resolution data and can be deployed quickly and at a lower cost than other platforms. However, they may have limited range and endurance compared to other platforms.
- Ground-based sensors: These include sensors mounted on vehicles, such as cars or boats, or stationary sensors, such as those mounted on poles or buildings. Ground-based sensors can collect high spatial and spectral resolution data, but may be limited in the area they can cover.
- Handheld sensors: These are portable sensors that can be carried by an individual, such as a handheld spectrometer or thermal camera. Handheld sensors can be used to collect high spatial and spectral resolution data, but may have limited range and may not be able to cover as large an area as other platforms.
In addition to these platforms, GIS can also make use of data from other sources, such as surveys, maps, and databases.
There are many different types of sensors that can be used for remote sensing, each with its own set of capabilities and limitations. Some common types of sensors used in remote sensing include:
- Multispectral sensors: These sensors collect data at multiple discrete wavelengths across the electromagnetic spectrum, typically in the visible, near-infrared, and shortwave infrared regions. Multispectral sensors can be used to distinguish between different materials or substances based on their unique spectral signatures.
- Hyperspectral sensors: These sensors collect data at a very high number of discrete wavelengths across the electromagnetic spectrum, typically in the visible, near-infrared, and shortwave infrared regions. Hyperspectral sensors can be used to distinguish between very small differences in the spectral signatures of materials, such as different types of minerals.
- Radar sensors: These sensors use radio waves to measure the distance to an object, and can be used to create images of the surface of the Earth. Radar sensors can be used to image the Earth’s surface through clouds and other forms of atmospheric interference, and can be used to measure the topography of the land surface.
- LiDAR sensors: These sensors use lasers to measure the distance to an object, and can be used to create high-resolution images of the surface of the Earth. LiDAR sensors can be used to measure the topography of the land surface with high accuracy and can be used to generate 3D models of the terrain.
- Thermal sensors: These sensors measure the temperature of the surface of the Earth, and can be used to create images of the surface based on the temperature of objects. Thermal sensors can be used to detect differences in temperature that may indicate different materials or substances, such as water and land.