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Thermal Emission Imaging System (THEMIS) Stamp Layer

The THEMIS Stamp Layer will display outlines (or "stamps") for all VIS and IR observations acquired by the Thermal Emission Imaging System (THEMIS) camera onboard Mars Odyssey. Since the THEMIS dataset is so large, there are numerous search parameters that allow users to retrieve stamps for only the observations they are interested in viewing.

Image:themis_main.png

Open the THEMIS Stamp Layer

  1. Open the Stamp Layer: In the Layer Manager chose "Add New Layer" -> "Stamps" -> "THEMIS Stamps".
  1. Search Parameter Categories: The search parameters are divided into categories since there are so many of them. Clicking on the down arrow on the right side of the category name will reveal all the search parameters in that category. The categories are:
    • Image Location Parameters
    • Viewing Conditions Parameters
    • Observation Parameters
    • IR Derived Science Parameters
    • Quality Parameters
    • Publication Parameters

    2. NOTE: A search can be performed with parameters set in multiple categories.


  1. Enter Search Parameters: It is not necessary to enter values for all parameters, but the more specific your search the faster it will be. The allowable values for each field are given in the quick reference table below.
  1. Perform Image Search: Clicking OK will make the Stamp Layer perform the search and display the results. Depending on how specific the search parameters are, it may take the Stamp Layer a few minutes to find and create stamps for all of the images. Once the stamps are displayed in the Viewing Window, users can right-click on an outline to either render the image (display the image data in JMARS) or view the image in a web browser.
  • If you click "Set Lon/Lat to bounds of View" then all of the stamps that are available in the Mainview will be added.


  • Once the stamps are added, there are different image types. Below is an example of the available types of images.

    • THEMIS Search Parameter Glossary

    Filter Type

    Acceptable Values

    Description
    Image Location Parameters

    Image ID(s)

    Any Specific Image ID Number(s)

    A unique identifier for each observation commanded; follows the pattern Xoooooiii, where:

    • X is the observation type (I, R, S, or V)
    • ooooo is the zero padded, 5-digit orbit number
    • iii is the zero padded, 3-digit image number

    Image Type

    VIS- Visible Observations

    IR- Infrared Observations

    Blank- Any Observation Type

    		 The type of the image i.e. Visible (VIS) or Infrared (IR).

    Min/Max Longitude

    0 - 360(Degrees of East Longitude)
    Blank(Any Longitude)

    		 This is the longitudeof the image's center. All values are based on the IAU 2000 aerocentric model of Mars with east positive longitude.

    Min/Max Latitude

    90 to -90(Degrees of North Latitude)
    Blank(Any Latitude)

    		 This is the latitude of the image's center. All values are based on the IAU 2000 aerocentric model of Mars with north positive latitude.

    Min/Max Local Time

    00.00-24.00(Given as HH.MM in Mars time)
    Blank(Any Local Time)

    This is the local time on Mars at the center of the image relative to a division of the Martian day into 24 equal parts. A martian day is slightly longer than 24 hours and 37 minutes, so these times are in "Mars hours, Mars minutes and Mars seconds".

    • "DAY" images are approximately those with a local time of 08.00-20.00 (8am-8pm)
    • "NIGHT" images are approximately those with a local time of 00.00-07.59 or 20.01-24.59 (0.00am-7.59am or 8.01pm-11.59pm)
    Viewing Conditions Parameters

    Min/Max Solar Longitude

    0 - 360(Northern Vernal Equinox = 0)
    Blank(Any Solar Longitude)

    This is the position of Mars relative to the Sun measured in degrees from the vernal equinox (start of northern Spring) position and is used to describe the Martian seasons. It is also known as heliocentric longitude and is usually abbreviated as Ls (pronounced "L sub S")

    • Northern Spring/Southern Autumn start at 0°
    • Northern Summer/Southern Winter start at 90°
    • Northern Autumn/Southern Spring start at 180°
    • Northern Winter/Southern Summer begin at 270°

    Min/Max Orbit

    816 - Present(No science images acquired before orbit 816)
    Blank(Any Orbit)

    		 Mars Odyssey orbit during which the observation was acquired. By definition, numbered orbits begin at the descending equator crossing of the spacecraft's polar orbit.

    IR Surface Temperature

    0 - 300(Degrees K, only applies to IR observations)
    Blank(Any Surface Temperature)

    		 Based on the average surface temperature (in degrees Kelvin) derived from band 9 of an IR observation.

    Min/Max Solar Incidence Angle

    0 - 180(Sun Directly Overhead = 0)
    Blank(Any Incidence Angle)

    		 Calculated for the center of each image, this is the angle between the Sun and a line drawn normal to the surface of the planet at the time the image was acquired. An angle of 0 degrees means the Sun is directly overhead and an angle of 90 degrees means the Sun is on the horizon. Daytime infrared images typically have incidence angles between approximately 0-90 degrees and nighttime infrared images typically have incidence angles greater than 90 degrees.

    Min/Max North Azimuth Angle

    0 - 360(3 o'clock position on image is due north = 0)

    Blank(Any North Azimuth Angle)

    		 The clockwise angle from an imaginary three o’clock line on the image to the north polar axis where the origin of both lines is at the center of a pixel at the center of the image.

    Min/Max Days Since Acquisition

    0 - Any Integer Number(Present Day = 0)
    Blank(Any Acquisition Time)

    		 The number of Earth days since the observation was acquired. This query will only return images that have been acquired AND downlinked. Since downlink data volumes can vary considerably, it may take a few days for very recent images to be downlinked and made available through JMARS.
    Observation Parameters

    Processing Stage

    ABRVIS Apparent Brightness Record
    BTRIR Brightness Temperature Record
    BWSBrowse Image
    DCSDecorrelation Stretched Image (four-panel)
    D964Decorrelation Stretched Image (RGB=964)
    D875Decorrelation Stretched Image (RGB=875)
    D642Decorrelation Stretched Image (RGB=642)
    EDRExperimental Data Record
    GEOGeometrically Registered Record
    PBTProjected IR Brightness Temperature Record
    RDRReduced Data Record
    BlankAny Processing Stages

    The ABR is derived from band 3 of a VIS-RDR QUBE (or first available band of the highest calibration product available). This file is a PDS IMAGE object with an attached PDS label.

    The BTR is derived from band 9 of a IR-RDR QUBE (or first available band of the highest calibration product available). See sdpsis.pdf for a summary of the image processing. This file is a PDS IMAGE object with an attached PDS label.

    The Browse Image is a simple PNG image product, which is similar to a standard PDS browse image.

    The DCS is a four-panel browse image composed of the following side-by-side, rectified images: BTR, D964, D875 and D642.

    The D964 is a decorrelation stretch image using THEMIS IR bands 9,6,4 as the RGB values, respectively.

    The D964 is a decorrelation stretch image using THEMIS IR bands 8,7,5 as the RGB values, respectively.

    The D964 is a decorrelation stretch image using THEMIS IR bands 6,4,2 as the RGB values, respectively.

    This file contains the raw THEMIS science data at the full resolution returned from the spacecraft, time ordered, with duplicates and transmission errors removed. This file is a PDS SPECTRAL_QUBE object with an attached PDS label.

    This file contains the geometric projection of the RDR standard data product; the data is stored as a multispectral ISIS CUBE file and associated with a PDS-style, detached label. Note that additional manipulation of the source data may invalidate the calibrated radiance values.

    The PBT is the projected equivalent of the BTR, which is derived from band 9 of a IR-RDR QUBE (or first available band of the highest calibration product available). See BTR entry above for more information.

    This file contains the radiometrically calibrated version of the THEMIS EDR standard data products. This file is a PDS SPECTRAL_QUBE object with an attached PDS label.

    Resolution (km/pixel)

    0.016-0.020THEMIS High-Resolution VIS
    0.034-0.038THEMIS Medium-Resolution VIS
    0.070-0.074THEMIS Low-Resolution VIS
    0.098-0.102THEMIS High-Resolution IR
    0.198-0.202THEMIS Medium-Resolution IR
    0.398-0.402THEMIS Low-Resolution IR
    BlankAny Resolutions

    		 The size of a pixel on the surface. For example, THEMIS high-resolution VIS images are 18m/pixel and THEMIS high-resolution IR images are 100m/pixel.

    Duration (s)

    1 - 600
    BlankAny Durations

    		 The length of time (in seconds) requried to collect all frames of all bands in the downlinked image; typical values range from 0.5 to 450.

    Bands (s)

    1 - 10
    BlankAny Bands

    		 Band numbers correspond to each layer contained in an image; up to 10 bands available in an IR image and up to 5 bands available in a VIS image.

    Summing

    1Highest Resolution

    2 Higher Resolution

    4 Medium High Resolution

    8 Medium Low Resolution

    16 Lower Resolution

    32 Lowest Resolution

    BlankAny Summing Factor

    		 Spatial average of NxN pixels of data before downlink; summing=1 implies that no spatial averaging has been applied. VIS images have summing modes of 1, 2, 4,8,16 and 32; IR images have summing modes of 1-320.

    Min/Max Roll Angle

    -180 to 180No Roll (Nadir-pointing) = 0
    BlankAny Roll Angle

    		 THEMIS nominally points nadir, but is occasionally rolled about the velocity vector for various reasons. For periods where the High-Gain Antenna has difficulty pointing at the Earth, Odyssey is sometimes flown in a rolled configuration for long periods of time.

    Min/Max Yaw Angle

    -180 to 180No Yaw = 0
    BlankAny Yaw Angle

    		 THEMIS nominally points nadir, but is occasionally yawed relative to the velocity vector for various reasons. For periods where the High-Gain Antenna has difficulty pointing to the Earth, Odyssey is sometimes flown in a yawed configuration for long periods of time.

    Pointing Mode

    NADIRNormal to the Surface
    OFF-NADIRNot Normal to the Surface and Not One of the Following Long-Term Off-Nadir Periods
    HGA_MITIGATION_R-10Rolled -10deg (Long-Term)
    HGA_MITIGATION_R-10Rolled -20deg (Long-Term)
    BlankAny Pointing Mode

    Although THEMIS is nominally pointed nadir, there are periods where THEMIS is pointed off-nadir for varying lengths of time.

    • NADIR: THEMIS is pointed perpendicular to the surface, which is the nominal pointing mode.
    • OFF-NADIR: THEMIS is pointed off-nadir, but for a limited period of time, usually covering only a few images.
    • HGA_MITIGATION_R-10: THEMIS was rolled -10deg off-nadir for multiple months in 2009 in order to mitigate communications probems with the High Gain Antenna caused by planetary positions and the antenna gimble's range.
    • HGA_MITIGATION_R-20: THEMIS was rolled -20deg off-nadir for multiple months in 2009 in order to mitigate communications probems with the High Gain Antenna caused by planetary positions and the antenna gimble's range.
    • Blank: All THEMIS pointing modes.

    Description

    Any Text
    BlankAny Description

    		 Description of the image target assigned by the mission planner. When searching by description, all text entered into the field will be directly compared with available descriptions.

    Mars Year

    25 - present
    BlankAny Mars Years

    		 The Mars year during which observations were collected. Following the convention established in Clancy [JGR April 2000, 1999JE001089], the first Themis mapping images were collected during Mars year 25.
    IR Derived Science Parameters

    MOLA Elevation

    -10 to +20Elevation at the image center
    BlankAny Elevations

    		 The average elevation value at the center of the image; values are derived from a 2 pixel per degree MOLA elevation map.

    Water Ice Opacity

    0.00 - 0.15(Typical values)
    BlankAny Water Ice Opacity

    		 Average derived water ice opacity (11µm) for a warm, daytime IR image; typical values range from 0.0 to 0.15.

    Dust Opacity

    0.00 - 0.25(Typical values)
    BlankAny Dust Opacity

    		 Average derived dust opacity (9µm) for a warm, daytime IR image; typical values range from 0.05 to 0.25.

    Maximum Thermal Inertia Range

    20 - 2000As calculated by the Kieffer model.
    BlankAny TI Value

    		 The range of maximum values for the average thermal inertia for each cold, nighttime IR image, derived using Keiffer's KRC thermal model. Model allows for thermal inertia values between 20 and 2000.

    Minimum Thermal Inertia Range

    20 - 2000As calculated by the Kieffer model.
    BlankAny TI Value

    		 The range of minimum values for the average thermal inertia for each cold, nighttime IR image, derived using Keiffer's KRC thermal model. Model allows for thermal inertia values between 20 and 2000.
    Quality Parameters

    Percent Missing

    0 - 100Percentage of lines missing from the observation.
    BlankAny Percent Missing

    		 Percent of total lines missing from the image; values range from 0 to 100, where 100 indicates complete data loss.

    Image Rating

    1 - Unusable
    2 - Poor
    3 - Poor/Fair
    4 - Fair
    5 - Fair/Good
    6 - Good
    7 - Very Good
    BlankAny Image Rating

    		 Subjective assessment of image quality ranging from unusable to good; assesment includes consideration of exposure, missing lines, instrument noise, and atmospheric features.

    IR Calibration Flag

    1 - IR images with a calibration error flag

    0 - IR images without a calibration error flag

    BlankAny IR Calibration Flag State

    		 This flag indicates that problems may have been encountered during the IR calibration routine and the user is advised to review the quality of the calibration. The flag is triggered by image saturation or under-saturation, length of time between the image and the shutter image, noise evaluation of the shutter image, and yaw angle of the Odyssey spacecraft.
    Publication Parameters

    Release ID

    0001 - 0035THEMIS PDS Releases
    BlankAny PDS Release

    		 Four digit, zero-padded identification number of the original PDS public release of the image.

    Modification Date

    yyyy-dddThh:mm:ssDate of ISIS QUBE creation/modification in UTC
    BlankAny Modification Date

    		 Creation time of the ISIS QUBE on the ground (in UTC), or the last official modification of the ISIS QUBE.

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