Enemy of the State and other Tom Clancy novels wow us with their futuristic technologies that can be used to observe the Earth's surface without actually being in contact with it. That's what we call remote sensing. However, in addition to their role in spy craft, did you know these technologies are also changing how agricultural production happens?
Remote sensing most often uses sensors on aerial or satellite platforms to record light from specific wavelengths that is reflected back from on-ground targets. Based on the characteristics of that target (for example, specific plants or groups of plants, minerals, and humanmade structures), the reflectance data can be used to develop geo-located maps of specific features on Earth's surface. Other sensors use various types of radar to determine characteristics such as object height or density. Different satellite or aerial systems can provide various spatial resolutions, depending on the system and the cost that the user is willing to pay. With the newest generation of commercial satellites, we can obtain spectral data with a ground resolution of as little as 1 meter. Aerial systems can provide images with a resolution as low as a few centimeters!
At the local level, "site-specific" or "precision" agriculture uses remotely sensed imagery from planes or satellites to determine variations in a single field. Coupled with soil maps and other global positioning system (GPS)-referenced data, this imagery can then be used by farmers and engineers to determine the cause of the variation and what should be done about it. Some examples follow.
- Pesticide use. Biologists have shown that certain insects preferentially go to the healthiest portion of the crop. Using remote sensing to map the field, scouting efforts can be targeted where the most rapid growth is occurring, and insecticides applied only where they are needed. This approach can reduce pesticide applications by as much as 70%, thereby resulting in economic benefits to the producer (and ultimately to the consumer) and environmental benefits through reductions in pesticide use.
- Irrigation. Soils and drainage frequently are not uniform across a field. When a plant is experiencing stress from drought, flood, or pests, it reflects more light in some portions of the spectrum rather than using that light in photosynthesis. These reflectance patterns can be readily detected and mapped with remote sensing instruments, providing the farmer with information to help decide when and where to irrigate (or fumigate).
- Agricultural policy. Remote sensing is being used at the regional--and even global--level to estimate crop acreage, crop productivity, and changes in land use over time. The ability to make these measurements is having a huge impact on our ability to optimize crop production, estimate crop needs, and appropriately modify national and international agricultural and food policies.
The Remote Sensing Technologies Center ( RSTC) at Mississippi State University is working closely with the Applications Division of NASA's Earth Science Enterprise and with the Earth Science Applications Directorate at the Stennis Space Center to integrate remote sensing technologies into the decision support systems used by state and federal agencies and natural resource managers. More than 80 faculty in departments from electrical engineering to agricultural economics to plant sciences are working in teams on these projects. The efforts have been consistent with the land-grant university concept: integration of research, teaching, and extension/outreach into a comprehensive effort that is focused on developing real-world applications. As an example, RSTC researchers are using spectral imagery to detect several key invasive species that have been introduced into the United States. This project is leading to high-tech efforts to monitor the extent of these infestations, predict their spread, and thereby develop new containment and control strategies.
Career opportunities for undergraduate and graduate students are exploding in the remote sensing field, particularly in applications of these technologies in agriculture and natural resource management. A number of different majors are relevant. Electrical, computer, and agricultural engineers are needed to develop the hardware and software that enable future applications. Plant scientists, soil scientists, biologists, and pest management specialists are needed to determine the relationships between the remote sensing imagery and what's actually occurring in the field. A whole new generation of crop scouts and consultants is realizing the career opportunities for those who understand how to obtain, use, and interpret remote sensing imagery. And it isn't limited to these fields, either. Agricultural economists, environmental managers, and even rural sociologists are finding that experience in these technologies opens doors.
If you are considering a career in remote sensing, coursework in general science and engineering, geospatial technologies, and geographic information systems (GIS) is a must. An understanding of fundamentals of remote sensing, especially how light is reflected from various surfaces and what affects this reflection, is critical. In addition, knowledge of GPS technology (especially its strengths and limitations) will give you a good background in developing effective applications of the technology in your chosen area of emphasis.
But be sure that you also develop the expertise on the applications side. Remote sensing is a great tool for agriculture, but it is just that, a tool; you need to have a background that enables you to use this tool effectively. In agricultural applications, that means you also need a strong background in areas such as soils, crop production, pest management, crop biology, and/or social sciences such as economics and sociology, depending on the type of position you're interested in.
Seeing space-age technology applied to down-to-earth uses such as agriculture provides a great insight into the future of science and technology development. The career opportunities are virtually unlimited for those who have the training and creativity to envision the possibilities.