Meaning of remote sensing
Remote sensing is the Collection of data by a recording device that is not in direct contact with the area.
Examples: Satellites, aircraft, drones, and aerial photographs
types of remote sensing
active remote sensing – this involves sending radiation out and then measuring the radiation that the earth is sending back e.g ocean current
passive remote sensing – measures the energy that is radiated from the earth e.g temperature
ADVANTAGES OF REMOTE SENSING:
- Allows coverage of very large areas.
- Can access inaccessible areas.
- Easy collection of data over a variety of scales and resolutions.
- There is no limitation on the extent of information that can be gathered from a single remotely sensed image.
- Data can easily be processed and analysed fast using a computer.
- Does not disturb the object or the area of interest.
- Cheap and fast method of collecting data of large areas.
- It is easier to locate floods or forest fire that has spread over a large region which makes it easier to plan a rescue mission easily and fast.
DISADVANTAGES OF REMOTE SENSING:
- Remote sensing is a fairly expensive method of analysis especially when measuring or analysing smaller areas.
- Requires a special kind of training to analyse the images.
- Human errors may occur during the analysing process.
- Sometimes different phenomena being analysed may look the same during measurement which may lead to classification error.
- Sometimes large-scale engineering maps cannot be prepared from satellite data which makes remote sensing data collection incomplete.