Mars Image Explorer|

All THEMIS images on the website are in the public domain, and should be credited to NASA/JPL/Arizona State University.

Acknowledgment of the THEMIS website and its resources will help ensure the continuing support necessary for the validation, archiving, and distribution of the Mars work at ASU. See Data Citation hints for more example references.

Yes! The THEMIS standard processing is described in the documents here, but you are, of course, always welcome to ingest the published products into your favorite image processing tools. However, we also have created an online processing tool which allows you to complete your own specialized processing using the THEMIS toolset and the ASU-MARS computers. Many exciting and new features for this tool are being developed based on feedback from users like you.

Currently the only way for the public to target a THEMIS image is through the MSIP education project. The MSIP project is open to groups of students in grades 5 through college sophomore.

Yes. Both water and ice are easily detected in the wavelength bands of the IR camera.

THEMIS can see through a small amount of atmospheric dust; however, even a small layer of surface dust (~100 um) will obscure any underlying thermal IR signatures. Diurnal thermal conductivity can occur through several centimeters of dust, but will only change the temperature of the dust on top.

Use one of the following methods to access the THEMIS data and documentation directories:

HTML Data Access (lower left on Search THEMIS page)

Browser access to the THEMIS Virtual Volume directory

Suitable for Wget data retrieval

FTP Data Access

FTP Server Address: pdsftp.mars.asu.edu

Login Name: anonymous

Password: your complete email address

JPL provideds a subscription service that will notify you weekly of the new THEMIS daily images and quarterly of new data releases. You may also select to receive Press Releases for a variety of other NASA space topics. You can sign up for the service through http://www.kintera.org

The five color filters of the THEMIS VIS camera do not span the full range of colors available to the human eye, so extensive processing, and an artistic touch, is applied to convert a raw image into an approximately "true color" image. Several of the THEMIS Team members are experts in VIS spectroscopy and have used their experience with the Hubble Space Telescope (HST) observations of Mars to generate a limited number of VIS color images. Their multi-step process:

The "Search THEMIS" tool is supported by a database that contains the coordinates for at least six points (usually significantly more) outlining the edges of each available THEMIS image. The image will be included in the results table if any of these outline points falls inside your latitude/longitude box, and your remaining criteria are also met.

Note that the previous THEMIS query tool relied only on three coordinates per image; therefore, this new method may return more positive results for the same latitude/longitude box.

The IR bands (1-10) used by THEMIS are centered at the following wavelengths (in microns):

6.78, 6.78, 7.93, 8.56, 9.35, 10.21, 11.04, 11.79, 12.57, 14.88

(Yes, the first two filters have the same spectral center.)

The VIS bands (1-5) used by THEMIS are centered at the following wavelengths (in microns):

0.425, 0.540, 0.654, 0.749, 0.860

The THEMIS investigation has several science objectives:

JMars is a Java-based, geospatial information system developed by ASU originally to support mission operations of the THEMIS cameras. Due to this relationship, JMars provides many specialized features which allow users to easily review, open, and manipulate the THEMIS images. Over the years it has expanded to include data sets from many other Mars missions, as well as applications for the Earth and Moon. Visit the JMars homepage to learn more about this versatile data analysis tool and download a copy for yourself.

The THEMIS Standard Data products (EDR, RDR, ABR, & BTR) are not projected into any coordinate system. The pixels in these products maintain the time, row, and column ordering (per band) of the raw observation; this arrangement is commonly referred to as "camera coordinates". Be aware that the bands of the QUBE products are not spatially registered within a single image.

The THEMIS Special Geometry products (GEO, LOC, PBT, and DCS) are map projected, with the coordinate system details documented in the headers and/or available labels. The following guidelines are used in routine processing:

The nominal resolution of the IR camera is about 100m/pixel.
The nominal resolution of the VIS camera is about 18m/pixel.

The resolution of either camera can be modified by spatial summing applied onboard before the images are downlinked; the image header and the Image Data table on the Details tab include the actual pixel resolution for each image.

THEMIS is a thermal emission imaging system. It contains two independent multi-spectral imaging sub-systems:

IR = a 10-band thermal infrared imager
VIS = a 5-band visible imager

A full description of the THEMIS instrument and a tutorial on spectroscopy is available here.

The THEMIS team provides several Standard data products and several Special data products through this website. All products are described in detail in the Product and Geometry documentation.

The THEMIS Browse images are available in a variety of formats (PNG, JPEG, TIFF, GIF, and PDF) and can usually be opened in your favorite image display tool.

The THEMIS image files (IMG, QUB, and CUB) files should be opened with an image processing tool that can handle multi-spectral images.
At ASU, we use either Davinci or JMars for the bulk of our data processing and analysis; NASA-PDS also provides a free image viewer: NASAView.

The schedule of previously released data is available here. In general, new data is released six months after ground receipt of the last raw data within each three month collection period:

Data Collection == Released

Jan–Mar (Year1) == Oct Year1

Apr–Jun (Year1) == Jan Year2

Jul–Sept (Year1) == April Year2

Oct–Dec (Year1) == July Year2

The four panels of the IR-DCS browse product are (from left to right):

• DCS where RGB = bands 875
• DCS where RGB = bands 964
• DCS where RGB = bands 642
• Stretched Brightness Temperature

The four panels of the IR-DCS browse product are (from left to right):

• DCS where RGB = bands 875
• DCS where RGB = bands 964
• DCS where RGB = bands 642
• Stretched Brightness Temperature