of CubeSats is very small compared to conventional satellites, which makes it
possible to launch dozens of CubeSats at once (Straub et al. 2013). More satellites
mean more eyes in the space to conduct more comprehensive observation. The cost
of CubeSat is extremely lower than traditional satellite and makes CubeSat a true
game changes (Woellert et al. 2011). It is exciting that an investment of approximately 50,000 dollars will let investors own a satellite. The PlanetLab is a pioneer on
commercializing CubeSat and has manufactured several CubeSat satellites and
delivered them into orbit as passengers on other launch missions (Chun et al.
2003; Peterson and Roscoe 2006). They built a website www.planet.com to sell
their images online. The system can view the historical images of every spot on the
Earth. Consumers can easily locate and order the scenes they need.
One common character of these satellites is that their datasets are for sales.
Meanwhile, the images of sensitive areas may reveal classified information which
impacts national security. So every image is processed to mosaic or encrypt those
sensitive regions before users encounter them. The owner companies usually establish a corresponding set of an online sales system for consumers to search and order
the images.
The use cases of ultra-high-resolution satellite images are countless. In precision
agriculture, ultra-high-resolution images are the basic information together with GPS
signal and in situ sensed data. Both multi-spectral and hyperspectral bands are
needed to comprehensively estimate crop status. Along with military, agricultural
community is another big customer of these companies.
However, the satellite images can only be one of the sources of agrogeoinformatics. The results of satellite-only studies are limited in many aspects as
satellite remotely senses the objects instead of directly touching them. The indirect
sensing may bring errors which may be amplified in the later processes and leads to
untrustworthy results. Data from other sources are required to assist and correct the
results.
4.2.2 Airborne Camera
Compared to satellites, airplanes and UAVs are closer to the land surface. They can
avoid most influences of atmosphere and have better flexibility in the air. Airborne
images can easily reach a much higher spatial resolution than space-borne images.
The reason is simple. It is similar to the human eye. You cannot see clearly a thing if
it is far away. If people move their eyes closer, the thing will become clearer. The
equipment in airborne observation has no big differences on imaging principle from
the instruments on satellites. Panchromatic sensors and multiple spectral sensors are
both available on the airborne platform.
Airborne platform is further divided into aircraft and UAV. The former employs
an aircraft to carry all the equipment and fly over the study area with pilots and
operators on board. The latter operates an UAV with operators standing on nearby
places to control its flying path. Normally, an aircraft flies higher and longer than
50
Z. Sun et al.
possible to launch dozens of CubeSats at once (Straub et al. 2013). More satellites
mean more eyes in the space to conduct more comprehensive observation. The cost
of CubeSat is extremely lower than traditional satellite and makes CubeSat a true
game changes (Woellert et al. 2011). It is exciting that an investment of approximately 50,000 dollars will let investors own a satellite. The PlanetLab is a pioneer on
commercializing CubeSat and has manufactured several CubeSat satellites and
delivered them into orbit as passengers on other launch missions (Chun et al.
2003; Peterson and Roscoe 2006). They built a website www.planet.com to sell
their images online. The system can view the historical images of every spot on the
Earth. Consumers can easily locate and order the scenes they need.
One common character of these satellites is that their datasets are for sales.
Meanwhile, the images of sensitive areas may reveal classified information which
impacts national security. So every image is processed to mosaic or encrypt those
sensitive regions before users encounter them. The owner companies usually establish a corresponding set of an online sales system for consumers to search and order
the images.
The use cases of ultra-high-resolution satellite images are countless. In precision
agriculture, ultra-high-resolution images are the basic information together with GPS
signal and in situ sensed data. Both multi-spectral and hyperspectral bands are
needed to comprehensively estimate crop status. Along with military, agricultural
community is another big customer of these companies.
However, the satellite images can only be one of the sources of agrogeoinformatics. The results of satellite-only studies are limited in many aspects as
satellite remotely senses the objects instead of directly touching them. The indirect
sensing may bring errors which may be amplified in the later processes and leads to
untrustworthy results. Data from other sources are required to assist and correct the
results.
4.2.2 Airborne Camera
Compared to satellites, airplanes and UAVs are closer to the land surface. They can
avoid most influences of atmosphere and have better flexibility in the air. Airborne
images can easily reach a much higher spatial resolution than space-borne images.
The reason is simple. It is similar to the human eye. You cannot see clearly a thing if
it is far away. If people move their eyes closer, the thing will become clearer. The
equipment in airborne observation has no big differences on imaging principle from
the instruments on satellites. Panchromatic sensors and multiple spectral sensors are
both available on the airborne platform.
Airborne platform is further divided into aircraft and UAV. The former employs
an aircraft to carry all the equipment and fly over the study area with pilots and
operators on board. The latter operates an UAV with operators standing on nearby
places to control its flying path. Normally, an aircraft flies higher and longer than
50
Z. Sun et al.