Coastal Services Center

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Remote Sensing Basics

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This section contains general remote sensing information of interest to the nation's coastal resource management programs.

What are remote sensing data?

Remote sensing is the science of gathering information at a distance, and it provides a descriptive, analytical way to identify geographic features. Remotely sensed data can include aerial photographs, satellite imagery, acoustic data, and radar imagery.

The use of remotely sensed data is increasing thanks to recent advancements in geographic information systems (GIS) and image processing capabilities. Information that previously was available only to large organizations is now suitable for most desktop computers and is used by all branches of government and the private and nonprofit sector. This international, multibillion-dollar industry includes the producers, collectors, analyzers, and sellers of spatial information and the associated tools.

Why use remote sensing?

Nothing brings the big picture into focus like remote sensing. Remote sensing is unsurpassed when it comes to getting data sets for a large area in a short amount of time. Remote sensing technologies are usually the most cost-effective means of getting information for areas that are inaccessible, far away, difficult to traverse, require a broad view, or are too large to effectively manage or assess with traditional surveying methods.

What are some of the most common uses of this technology by coastal resource managers?

• Shoreline mapping and erosion analysis
• Floodplain mapping
• Land cover and land cover change mapping
• Habitat mapping
• Wetland mapping and evaluation
• Submerged aquatic vegetation mapping
• Regional planning
• Water quality monitoring
• Coastal management permitting
• Oil and toxic spill response planning
• Navigation
• Dredge disposal site monitoring
• Base maps

What are some of the more common data sets acquired with remote sensing technology?

• Topography measurements
• Land cover and land cover change measurements
• Vegetation type and health
• Infrastructure locations
• Sea surface temperature
• Sea surface roughness
• Ocean color and chlorophyll
• Shallow water bathymetry
• Shoreline location

How are remote sensing data obtained?

There are numerous companies in the business of acquiring and processing remotely sensed data. The federal government also collects remote sensing imagery to accomplish its mission of protecting the national economy, security, and environment. Coastal managers use both of these avenues to acquire data. State and local organizations often band together to acquire data that they then use for a variety of purposes.

What are some of the considerations to be made before acquiring data?

Spatial resolution, which refers to the amount of detail recorded by a sensor, is an important consideration. Different remote sensing technologies provide data at varying resolutions. As the detail, or spatial resolution, increases, the area covered generally decreases. Higher resolution requirements often mean higher data costs. Before acquiring data, consider the area's size and the amount of detail needed to meet your needs.

Federal, state, and local governments are a good source of free, shared, or inexpensive data, but many efforts require specific data that are purchased from the private sector. No matter what the source, users should understand where the data originated from (satellite or aerially derived? archived or acquired?), the final data format, possible licensing requirements or restrictions on data distribution, and associated expertise, hardware, and software needs. If airborne data are going to be acquired, users need to know of potential weather implications that may affect a project timeline, as well as the costs associated with purchasing raw data, flying an aerial mission, using a sensor for a set amount of time, and processing data.

A key for determining the value of investing in remote sensing and spatial information technologies is a comparison of the costs and benefits relative to traditional monitoring methods. Remote sensing data augments other sources of data but is rarely a stand-alone solution.

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