The Azimuth Project
Remote sensing

Contents

Idea

Wikipedia defines:

Remote sensing is the small- or large-scale acquisition of information of an object or phenomenon, by the use of either recording or real-time sensing device(s) that are wireless, or not in physical or intimate contact with the object (such as by way of aircraft, spacecraft, satellite, buoy, or ship). In practice, remote sensing is the stand-off collection through the use of a variety of devices for gathering information on a given object or area. Thus, Earth observation or weather satellite collection platforms, ocean and atmospheric observing weather buoy platforms, the monitoring of a parolee via an ultrasound identification system, Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), X-radiation (X-RAY) and space probes are all examples of remote sensing. In modern usage, the term generally refers to the use of imaging sensor technologies including: instruments found in aircraft and spacecraft as well as those used in electrophysiology, and is distinct from other imaging-related fields such as medical imaging.

Details

Also from Wikipedia:

There are two main types of remote sensing: passive remote sensing and active remote sensing. Passive sensors detect natural radiation that is emitted or reflected by the object or surrounding area being observed. Reflected sunlight is the most common source of radiation measured by passive sensors. Examples of passive remote sensors include film photography, infrared, charge-coupled devices, and radiometers. Active collection, on the other hand, emits energy in order to scan objects and areas whereupon a sensor then detects and measures the radiation that is reflected or backscattered from the target. RADAR is an example of active remote sensing where the time delay between emission and return is measured, establishing the location, height, speed and direction of an object. Remote sensing makes it possible to collect data on dangerous or inaccessible areas. Remote sensing applications include monitoring deforestation in areas such as the Amazon Basin, glacial features in Arctic and Antarctic regions, and depth sounding of coastal and ocean depths. Military collection during the cold war made use of stand-off collection of data about dangerous border areas. Remote sensing also replaces costly and slow data collection on the ground, ensuring in the process that areas or objects are not disturbed.

Orbital platforms collect and transmit data from different parts of the electromagnetic spectrum, which in conjunction with larger scale aerial or ground-based sensing and analysis, provides researchers with enough information to monitor trends such as El Niño and other natural long and short term phenomena. Other uses include different areas of the earth sciences such as natural resource management, agricultural fields such as land usage and conservation, and national security and overhead, ground-based and stand-off collection on border areas.

Remote sensing by satellites

In weather and climate research remote sensing is mainly used to denote remote sensing by satellites. Here is a figure from Robert Schowengerdt, that shows mainly sensors on satelites except AVIRIS and Hymap:

ref1 figure 1.1 v2

In the figure of remote sensing systems they have used; V for visible , NIR for Near Infrared,LWIR,MWIR,SWIR for long-,mid- and shortwave. P for panchromatic or black and white visible for the human eye.

If you want to build your own receiver that is feasible and for example MODIS? for land science which was launched on Earth Observation Satellites Terra and Aqua, has a specification in the fourth reference below and Wikipedia on MODIS has a large part of the specification and its 35 bands covering land, ocean, atmosphere, and thermal variables like humidity, ozone and cloud temperature and heights.

Some links to satellite programs:

Open source Software

Opticks is an expandable remote sensing and imagery analysis software platform that is free and open source. If you are interested you can learn about the history of Opticks. If you’ve used commercial tools like: ERDAS IMAGINE, RemoteView, ENVI, or SOCET GXP, then you need to give Opticks a try. Unlike other competing tools, you can add capability to Opticks by creating an extension. Opticks provides the most advanced extension capability of any other remote sensing tool on the market.

References

category: earth science