UAV, but not in every case. Many restrictions apply on the fly of a measuring
aircraft which is considered to be a spy activity in some countries. They need
authorizations from the authorities and wait until the approval of air traffic control
department when the path intersects with civil aviation routes or military practice
routes. This process may take a very long time. Aircraft-based observation is popular
in the late 1990s and the first decade of this century (Eichkorn et al. 2002; Mays et al.
2009; Möhler et al. 1993). But as UAVs and satellites enter the competition, aircraft
approach is gradually abandoned by civil use. The military and government are still
using it as they are familiar with the process and can easily obtain the approval. The
military has plenty of aircraft equipped with sensing devices so that they can observe
as they are in the air. Naturally, the observed data are for military and government
purposes and not available for agriculture. The costs include the gas, maintenance
fee, depreciation, installation of equipment, labor of operators and pilots, insurances,
etc. Overall, the aircraft measurements are more expensive on the cost per unit area
than satellite and UAV. As aircraft-based observation is case-specific and has no
systematic data management, the data from aircraft is rarely available in public. The
UCAR (University Corporation for Atmospheric Research) (Hallgren 1974) Earth
Observing Laboratory (EOL) manages two research aircrafts, HIAPER and C-130,
and accepts requests for observing tasks. Some of the acquired data are made
available online via anonymous FTP server.
1 Those datasets can help people study
the pattern of specific areas but are not suitable for long-term and large-scale
monitoring and forecast in agriculture.
UAV, also called drone, is an ideal alternative to avoid the limitation of aircraft.
The resolution of images obtained by UAV sensing can be less than 1 cm to 10 cm.
The recent fierce competition among drone manufacturers helps reduce the price to a
very affordable level for companies and individuals. We quote the prices for some
models of the major brands to give a overview and sense of the drone market.
Table 4.2 is given with the price and parameters of the quoted drones. Here we
exclude the military drones like a RQ-4 Global Hawk (Haulman 2003), MQ-1 Gray
Eagle (Cote 2015), and RQ-11 Raven (Arjomandi et al. 2006; Cook 2007). Those
drones are extremely expensive, high maintenance cost and warfare oriented.
Civil drones generally have two options: consumer and professional (Chen et al.
2016). Based on our survey, there is no obvious difference on flying distance,
duration, and data quality between the two. The major gap, if not minor, is the
Table 4.2 Some drones for precision farming (the price data are quoted the lowest on 5/31/2017)
Brand model
Camera
Resolution Duration Distance Price
DJI phantom 3 CP.PT.000181 ZENMUSE X3 12.4 MP
23 min
3 mile
$799
DJI MATRICE 100
Customizable
–
40 min
3 mile
$3299
DJI T600 inspire 1
ZENMUSE X3 12.4 MP
18 min
1.3 mile $1899
Bebop drone 2
12.5 MP
25 min
300 m
$399
1 https://www.eol.ucar.edu/all-field-projects-and-deployments
4 Agro-geoinformatics Data Sources and Sourcing
51
aircraft which is considered to be a spy activity in some countries. They need
authorizations from the authorities and wait until the approval of air traffic control
department when the path intersects with civil aviation routes or military practice
routes. This process may take a very long time. Aircraft-based observation is popular
in the late 1990s and the first decade of this century (Eichkorn et al. 2002; Mays et al.
2009; Möhler et al. 1993). But as UAVs and satellites enter the competition, aircraft
approach is gradually abandoned by civil use. The military and government are still
using it as they are familiar with the process and can easily obtain the approval. The
military has plenty of aircraft equipped with sensing devices so that they can observe
as they are in the air. Naturally, the observed data are for military and government
purposes and not available for agriculture. The costs include the gas, maintenance
fee, depreciation, installation of equipment, labor of operators and pilots, insurances,
etc. Overall, the aircraft measurements are more expensive on the cost per unit area
than satellite and UAV. As aircraft-based observation is case-specific and has no
systematic data management, the data from aircraft is rarely available in public. The
UCAR (University Corporation for Atmospheric Research) (Hallgren 1974) Earth
Observing Laboratory (EOL) manages two research aircrafts, HIAPER and C-130,
and accepts requests for observing tasks. Some of the acquired data are made
available online via anonymous FTP server.
1 Those datasets can help people study
the pattern of specific areas but are not suitable for long-term and large-scale
monitoring and forecast in agriculture.
UAV, also called drone, is an ideal alternative to avoid the limitation of aircraft.
The resolution of images obtained by UAV sensing can be less than 1 cm to 10 cm.
The recent fierce competition among drone manufacturers helps reduce the price to a
very affordable level for companies and individuals. We quote the prices for some
models of the major brands to give a overview and sense of the drone market.
Table 4.2 is given with the price and parameters of the quoted drones. Here we
exclude the military drones like a RQ-4 Global Hawk (Haulman 2003), MQ-1 Gray
Eagle (Cote 2015), and RQ-11 Raven (Arjomandi et al. 2006; Cook 2007). Those
drones are extremely expensive, high maintenance cost and warfare oriented.
Civil drones generally have two options: consumer and professional (Chen et al.
2016). Based on our survey, there is no obvious difference on flying distance,
duration, and data quality between the two. The major gap, if not minor, is the
Table 4.2 Some drones for precision farming (the price data are quoted the lowest on 5/31/2017)
Brand model
Camera
Resolution Duration Distance Price
DJI phantom 3 CP.PT.000181 ZENMUSE X3 12.4 MP
23 min
3 mile
$799
DJI MATRICE 100
Customizable
–
40 min
3 mile
$3299
DJI T600 inspire 1
ZENMUSE X3 12.4 MP
18 min
1.3 mile $1899
Bebop drone 2
12.5 MP
25 min
300 m
$399
1 https://www.eol.ucar.edu/all-field-projects-and-deployments
4 Agro-geoinformatics Data Sources and Sourcing
51