This term is often used when considering image acquisition through remote sensing and refers to the time of the year during which an image is taken. Leaf-on and leaf-off refer to the presence or lack of the foliage of woody species. Leaf-on imagery means that there is foliage on the tree or shrub species (or the species of interest). Leaf-off means that there is no foliage or a reduced amount of foliage on the tree or shrub species.
Sometimes it …
How can I utilize free satellite imagery?
You can use free satellite imagery for a variety of applications. From a vertical or near vertical view, you can visually look at changes across a landscape or locate evidence of change from your observations. Most free images can be viewed in desktop applications that will open JPEGs or TIFFs. However, if you want to do more than just visually look at the imagery, you will most likely need to use either GIS or image processing software. These types of …
Where can I find free aerial imagery?
Aerial imagery can be very useful in the classroom, public meetings, and land management planning and for general historical purposes. Aerial photography is one type of geospatial data that may require a large monetary investment. However, there are sources from which you may be able obtain aerial imagery for your area free of charge.
Most states have participated in national and statewide imagery programs since the middle 1990s (some have been involved even longer). Many of these states provide free …
How can I obtain an aerial or satellite image for my area?
Historic aerial photography (in some cases dating back to the 1930s) is often available from the Natural Resources Conservation Service (NRCS) regional/local office or the Farm Service Agency (FSA) office. Recently acquired aerial photography can often be obtained from your local government (city/county government) office. Contact the local government GIS coordinator. Most cities and larger towns have someone responsible for GIS. If not, then often the planning department, assessor’s office, or engineering department is a good place to get started.…
What is remote sensing, and how can it be used?
In the area of geospatial technologies, remote sensing generally refers to satellite imagery or aerial photography.
Remote sensing provides the ability to observe an object without coming in direct contact with that object. Your eyes are extremely sophisticated remote sensing devices!
The “bird’s eye” view from the satellite or airplane, in combination with its ability to store, analyze, and display the sensed data, make remote sensing a powerful tool. Remote sensing techniques generally fall into two categorizes: active remote sensing …