USGS Groundwater Information
ESPD Hydrogeophysics Branch
Handheld Thermal Imaging Cameras > Resources for USGS Users
![[Photo: USGS scientists holding thermal imaging camera]](images/FLIR-T620.jpg "Photo: Thermal imagning camera")
Figure 1. Example of portable, handheld thermal imaging camera used in USGS groundwater studies.
Three high-resolution handheld thermal imaging cameras are available for USGS use in groundwater/surface-water interaction studies and other investigations where thermal signatures are of interest. The cameras (fig. 1) are part of the Office of Groundwater geophysical-equipment program, which provides USGS scientists with state-of-the-art geophysical hardware and software for program development, staff training, and unique project requirements.
Potential field applications are being explored within the Water Mission Area and in interdisciplinary work with other USGS Mission Areas.
On this page you will find:
Infrared (IR) radiation is a portion of the electromagnetic spectrum. An IR camera captures the emitted thermal radiation of objects in the view screen (figs. 2 and 3) in the portion of the electromagnetic spectrum ranging from 8 to 15 micrometers in wavelength. (Visible light wavelengths are 400 to 750 nanometers.) The amount of emitted IR radiation is dependent on the temperature of an object. The emitted radiation level is also affected by other parameters such as emissivity and reflectivity. Some materials, such as geranium used in the IR camera lens, transmit IR radiation very well. Other objects, which transmit visible light, such as glass, will appear opaque in an IR image.
Emissivity is the ratio of an object's emitted radiation relative to a perfect emitter. An emissivity of 1 corresponds to a perfect blackbody, whereas shiny metallic or well-polished surfaces will have a lower emissivity. If differences in emissivity are not accounted for, low emissivity objects will have a lower apparent temperature than a corresponding high-emissivity object of the same temperature.
Similar to visible light, infrared radiation will reflect off of surfaces, including water. Because water is highly reflective to thermal energy, care must be taken to obtain an accurate measurement of water surface temperature. Common water reflection artifacts include apparent temperatures well below freezing. This artifact can be induced by interference with the atmosphere (i.e., sky reflection). Changing the angle of the shot can often eliminate this problem.
As with any geophysical method, the greater the signal contrast, the better the potential results. Selection of times of day or season where there are maximum temperature contrasts can improve results. For example, the temperature contrast between groundwater and surface water is often greatest during summer and winter months, so temperature surveys intended to assess groundwater/surface-water interaction are often conducted during these months.
![[ Image: Thermal image of groundwater discharging into a pond. Refer to caption for description. ]](images/BG-FLIR-IR_1382-web.jpg "Image: Thermal image of groundwater discharging into a pond.")
Figure 2. Thermal image indicates water temperature, where warmer temperatures are represented as red and cooler temperatures as blue. The image presents an area where cooler groundwater (blue) may be discharging into a warmer (orange) pond. Note that the camera can be set to record the location and orientation of the camera (shown here in the lower right corner of this image) in the file metadata. The image spans an area about 0.5 meters across. The temperature scale is in degrees Celsius. USGS/Image by Martin Briggs.
![[ Image: Thermal image of groundwater discharging into a pond. Refer to caption for description. ]](images/BG-FLIR-IR_1821-web.jpg "Image: Thermal image of groundwater discharging into a pond.")
Figure 3. Thermal image indicates water temperature, where warmer temperatures are represented as red and cooler temperatures as blue. In this image, no significant variation is observed in surface temperature of the warm (yellow) pond. The image spans an area about 3 meters across. The temperature scale is in degrees Celsius. USGS/Image by Martin Briggs.
Three cameras are currently available through the Office of Groundwater geophysical-equipment program. The published manufacturers' specifications are listed below. Please note that the published specifications do not take into account the emissivity, reflection, and signal contrast issues discussed above, and actual field results may vary.
|
FLIR i7 |
FLIR T620 |
FLIR T640 |
|---|---|---|---|
Infrared (IR) image size (pixels) |
140 x 140 |
640 x 480 |
640 x 480 |
Video? |
no |
yes |
yes |
Visible light camera? (in addition to IR) |
no |
yes |
yes |
Internal GPS? |
no |
yes |
yes |
MSX? (visual + IR integration) |
no |
yes |
yes |
Zoom? |
none |
1-4x |
1-8x |
Field of View, in degrees |
29 |
25 |
25 |
Thermal Sensitivity, in degrees Celsius |
0.1 |
0.05 |
0.04 |
Temperature Range, in degrees Celsius |
0 to 250 |
-40 to 650 |
-40 to 650 |
Accuracy, in percent (%) or in degrees Celsius |
2% or 2C |
2% or 2C |
2% or 2C |
Focus |
Focus free |
Auto or manual |
Auto or manual |
Screen, in inches (in) |
2.8 inches, color |
4.3 inches, color |
4.3 inches, color |
View finder? |
no |
no |
yes |
File storage capacity |
> 5000 |
>1000 |
>1000 |
Battery Life, in hours (approximate) |
5 |
3 |
3 |
Weight, in pounds (lbs) |
<1 |
3 |
3 |
For additional information about the webinar, including slides for accessibility purposes and a downloadable video, please see the seminar web page.
Note: Best viewed in Chrome. To stream the video below, you may be prompted to log in to Bison Connect using your Active Directory password. The video is for internal USGS only. Do not release or distribute.
You can also download the video as WMV [43.4MB] or MP4 [5.5MB] file and view it locally for a better viewing experience.
The presentation slides [112MB PPTX] are provided for accessibility purposes. If for accessibility reasons, the recording and slides are not adequate, please contact the Branch of Geophyisics so that we can determine how best to address your training needs
The resources in this section are for internal USGS use. If you have feedback or suggestions, please contact Marty Briggs.
This MATLAB script extracts latitude, longitude, and heading from FLIR T640BX image metadata, and converts latitude and longitude into decimal degrees. The information is exported to an ASCII file.
To suggest additions or changes to this list, please email us.
Becker, M.W., 2006, Potential for satellite remote sensing of ground water: Ground Water. v. 44, no. 2, pages 306–318. Available online at http://info.ngwa.org/gwol/pdf/062381235.pdf
Briggs, M.A., Voytek, E.B., Day-Lewis, F.D, Rosenberry, D.O., and Lane, J.W., 2013, The hydrodynamic controls on thermal refugia for endangered mussels in the Delaware River ![[Link exits the USGS web site]](http://water.usgs.gov/ogw/images/icons/icon_out.png){kind=icon}
: Environmental Sciences and Technology: v. 47, no. 20, p. 11423-11431. doi:10.1021/es4018893.
Culbertson, C.W., Huntington, T.G., and Caldwell, J.M., 2007, Nutrient enrichment in estuaries from discharge of shallow ground water, Mt. Desert Island, Maine: U.S. Geological Survey Scientific Investigations Report 2007–5188, 34 p. Available online at http://pubs.usgs.gov/sir/2007/5188/
Deitchman, R. and Loheide, S., 2009, Ground-based thermal imaging of groundwater flow process at the seepage face: Geophysical Research Letters, v. 36, L14401, doi:10.1029/2009GL038103 Available online at http://www.agu.org/pubs/crossref/2009/2009GL038103.shtml
Pfister, L., McDonnell, J.J., Hissler, C., and Hoffmann, L., 2010, Ground-based thermal imagery as a simple, practical tool for mapping saturated area connectivity and dynamics: Hydrological Processes, DOI: 10.1002/hyp.7840. Available online at http://www.cof.orst.edu/cof/fe/watershd/pdf/2010/Pfister%20et%20al%202010_HP.pdf
Raabe, E.A., and Bialkowska-Jelinska, Elzbieta, 2010, Thermal imaging of the Waccasassa Bay Preserve—Image acquisition and processing: U.S. Geological Survey Open-File Report 2010–1120, 61 p. Available online at http://pubs.usgs.gov/of/2010/1120/
Röper, T., Greskowiak, J. and Massmann, G., 2013, Detecting Small Groundwater Discharge Springs Using Handheld Thermal Infrared Imagery: Ground Water, doi: 10.1111/gwat.12145
Stevens, H.H., Ficke, J.F., and Smoot, G.F., 1975, Water, temperature - influential factors, field measurement, and data presentation: U.S. Geological Survey Techniques of Water-Resources Investigations, Book 1 Chapter Dl, 65 p. Available online at http://pubs.usgs.gov/twri/twri1-d1/
Stonestrom, D.A., and Constantz, J., 2003, Heat as a tool for studying the movement of ground water near streams: U.S. Geological Survey Circular 1260, 96 p. Available online at http://pubs.usgs.gov/circ/2003/circ1260/
For more information or to schedule use of the camera for a USGS groundwater study, contact Marty Briggs (mbriggs@usgs.gov or 860-487-7402 x19) in the Office of Groundwater, Branch of Geophysics.
Offices are encouraged to submit their requests early in project planning process. The camera is booked on a first-come, first-served basis, with scheduling priority given to first-time users.
Hypertext links and other references to non-USGS products, trade names, and (or) services are provided for information purposes only and do not constitute endorsement or warranty, express or implied, by the USGS, USDOI, or U.S. Government, as to their suitability, content, usefulness, functioning, completeness, or accuracy.
