Unveiling the Power of Remote Sensing in Site and Environment Analysis

Construction and various other industries are leveraging revolutionary technologies to streamline their operations. Remote sensing is a cutting-edge technology transforming the landscape of site/land analysis. This approach is commendable because it captures and processes substantial data from a distance.

In this write-up, we will cover the meaning of this technique, its areas of application, types, advantages, and limitations. 

What is Remote Sensing?

Remote sensing is a geospatial discipline that collects extensive data about surfaces or objects from a distance. It detects and observes the physical features of a specific area without making direct contact. Satellite and aircraft-based sensor technologies sampling electromagnetic radiation from the Earth make it possible.

This discipline has been around since 1800. During that time, professionals carried out the first airborne surveys using pigeons, kites, hot air balloons, and film cameras. In the 1900s, they started using airplanes for aerial photography. In 1957, satellite technology was utilized for remote sensing for the first time. 

The last two decades have seen a significant increase in Earth observation satellites, with 1460 satellites in orbit. The development of robotics and drones has expanded the number of platforms available for this purpose.

Applications of Remote Sensing

Urban Planning and Development

This technology is aiding urban planners in monitoring, planning, and development. The data obtained through satellites and drones helps the planners discover the ideal sites for urban development considering the potential effects on the environment. 

Professionals harness this data to monitor the progress of construction projects and observe land use in urban localities. Remote sensing is a continuous process that provides urban developers with the latest data to assist them in planning.

Environmental Observation

Environmental observers utilize remote sensing to monitor the environment by capturing images of large areas through satellites. This way, they can detect changes in the climate and use the obtained data to prepare for the climate impact assessment. 

For instance, this technology simplifies the locating and monitoring of oil spills and rainforest deforestation. It also facilitates indicating water quality parameters and monitoring the impact of human activities on the environment. Through GIS technology, professionals create several spatial planning scenarios to examine and simulate them.

Agriculture and Resource Management

In the 21st century, remote sensing has gained popularity among farmers to observe crop health. It aids them in irrigating the fields and performing other crucial tasks whenever required. The light reflected from crops and plants, which is captured by multispectral sensors, makes it possible. 

These sensors are examples of passive sensors. They help capture image data within specific wavelength ranges in the electromagnetic spectrum. Traditional RGB color images are the most common example of multispectral pictures. Three spectral image planes can be found in it. 

Remote sensing also contributes to obtaining data about the state of natural resources. It is essential for protecting or analyzing the impact of natural change or policy. Observing vegetation, soil, geology, and land cover is easy in this context. 

Types of Remote Sensing

There are two types of remote sensing: active and passive. Let’s discuss them below.

Active Remote Sensing

In this type, energy is released by sensors and they detect the signals coming back through it. For example, LiDAR and radar are the two premier examples of the technology used in this approach. 

Active Remote Sensing instruments

This process begins with every active sensor sending a signal to the object and monitoring the received quantity of the response. Most of the devices are equipped with microwaves as they ensure protection from different weather conditions. The techniques in this method are set apart by transmitting light or waves and determining things such as height, distance, atmospheric conditions, etc. Professionals use the below-mentioned instruments in this method.

LiDAR: This system measures distance with light. LiDAR focuses on light impulse transmission and checks the retrieved quantity. Experts multiply the time by the light’s speed to comprehend the target location and distance.

Radar: It is a sensor that ranges using the radio signals. An antenna emitting impulses is its stand-out feature. This approach begins with the radar’s energy flow meeting an obstacle and it scatters back to the sensor to some degree. Professionals estimate the distance of the target based on the amount and traveling time.

Laser: This technique integrates with LiDAR to measure elevation.

Sounder: It emits impulses to vertically study the weather conditions. It happens in the case of it falling into the active category.

Ranging instruments: This type of active remote sensing uses one or two identical devices on various platforms signaling each other to estimate the range.

Scatterometer: This device helps in gauging backscattered radiation.

Passive Remote Sensing

Passive sensing, unlike active, does not organize its energy to the researched surface or object. This technique relies on the natural energy such as sunrays that bounce from the target. Hence, proper sunlight is essential for this method as no sunlight will result in nothing being reflected. 

Hyperspectral or multispectral sensors are employed in this type of sensing. It uses several band combinations to measure the acquired quantity. Several channels (two wavelengths and more) make these combinations distinguishable. Bands’ scope contains spectra within and beyond human vision (visible, IR, NIR, TIR, microwave). Professionals use the below-mentioned instruments in this method.

Spectroradiometer: It discovers the radiation’s power in multiple band ranges.

Spectrometer: It shows the difference between spectral bands and analyses them.

Radiometer: This instrument measures the radiation power, which an object emits in specific band ranges (visible, IR, microwave).

Hyperspectral Radiometer: It operates with the most precise type of passive sensor. The hyperspectral radiometer’s extremely high resolution allows it to distinguish numerous narrow spectral bands within visible, NIR, and MIR regions.

Sounder: It can easily sense the environmental conditions vertically.

Imaging Radiometer: It reproduces the image through its capability to scan the surface or object.

Accelerometer: It monitors changes in speed per unit of time.

Advantages of Remote Sensing

Expanded Geographical Coverage

This approach enables professionals from various industries to gather information from large geographical areas in a short time. It is useful in the observation of atmospheric changes and natural resources. 

The data collection scope and speed of this method are ideal for disaster response and offer real-time updates about the damage. It provides coverage for risky or inaccessible areas, like volcanos, etc. 

Multi-spectral and Multi-angle Visuals

Remote sensing is ideal for capturing pictures from several wavelengths and angles, leading to gaining valuable insights. Hence, it is widely used in mineral exploration, agricultural management, and environmental monitoring. 

Identifying particular features such as water quality or vegetation is easier with multi-spectral imaging. It also assists in planning and management. 

Usage in Military Intelligence and More Industries

Military personnel use remote sensing to gather intelligence and conduct surveillance. This technology is ideal for recognizing military installations, monitoring borders, and detecting potential security threats. 

Moreover, it has applications in agriculture, geographical exploration, disaster response and management, climate observation, urban planning and management, water resource management, transportation planning, and wildlife monitoring.

Limitations of Remote Sensing

High Cost and Need for Special Skills

Implementing and maintaining this method is costly. Purchasing the equipment, processing data, and maintaining requires high investment. Hence, it may not be popular in some fields in the developing countries.

Additionally, skilled and knowledgeable professionals are required to implement this technology. Thus, some firms may not be able to use it if they can’t train the employees or hire them.

Sun Angle and Atmospheric Conditions

Another limitation of remote sensing is that shadows and distortions created due to the sun angle can cause issues in interpreting some features precisely. 

Also, clouds, aerosols, and haze are some of the atmospheric conditions that can obscure or distort the images. It can reduce the accuracy and usefulness of this technique.

Difficulty in Identifying Underground Features

It is not easy to capture the deep ocean or underground resources with this approach as it does not obtain thorough images of certain areas. 

Lack of quality in resolution and data is another issue that can make the data useless and inaccurate. It happens due to technical problems such as spectral and spatial resolution of the sensor and image quality.

Human-made Buildings and Privacy Concerns

Remote sensing may find it difficult to gather data and interpret it precisely due to the presence of buildings, bridges, and roads. Thus, there is no guarantee of the accuracy and usefulness of this data in some applications. Furthermore, the use of this method raises privacy concerns when it comes to surveillance purposes. 

Final Thoughts

This cutting-edge technology’s future looks promising as data analysis and technology are advancing. It is augmenting the resolution of data and quality. It has been used in multiple fields such as disaster response, natural resource management, urban planning and development, and military intelligence. 

However, there are also some limitations. Hence, consider all these advantages and disadvantages keeping the project requirements into account and moving towards achieving ease in operations.

FAQs

Q 1: What is GIS remote sensing?

Ans: Geographic Information System (GIS) facilitates capturing, managing, storing, manipulating, analyzing, and presenting spatial or geographic data. Its integration with remote sensing offers critical spatial data.

Q 2: What is the principle of remote sensing?

Ans: The basic principle of this approach is that recognizing and distinguishing objects and surfaces is easy based on the radiant energy that they emit/reflect. Various surfaces and objects such as water, soil, or plants return energy in different quantities and numerous electromagnetic bands. Below are the factors, which impact this.

Object’s properties: Physical and chemical composition, surface roughness, and material type.

Radiation’s properties: Wavelength, incidence angle, and radiant intensity.

Q 3: What are the components of remote sensing?

Ans: The components of this technique are as follows: light source, target, radiation, and atmosphere, using sensors to record energy, processing, and analysis.