Visible and Infrared Mineralogical Mapping Spectrometer (OMEGA) Stamp Layer

The OMEGA Stamp Layer will display stamps for all observations acquired by the Visible and Infrared Mineralogical Mapping Spectrometer (OMEGA) aboard the European Space Agency's Mars Express orbiter. While the search interface is similar to the THEMIS Stamp Layer, there are some differences that allow users to search for observations based on the unique parameters associated with OMEGA observations.


Open the OMEGA Stamp Layer

  1. Open the Stamp Layer: Chose "Add New Layer" -> "Imagery" -> "OMEGA" OR "Add New Layer" -> "Instrument" -> "OMEGA".


  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:
    • Basic Parameters
    • Advanced Parameters
    NOTE: A search can be performed with parameters from multiple categories.
  1. Enter Search Parameters: It is not necessary to enter values for each parameter, 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 followed by more detailed descriptions of each search parameter.
  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 view the image in a web browser. A rendering option is not currently available for OMEGA data.

OMEGA Search Parameter Glossary

Filter Type

Acceptable Values


Basic Parameters

Image ID(s)

Any Specific Image ID Number(s)

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

  • nnnn is the zero padded, 4-digit orbit number
  • x is a sequential one-digit hexadecimal number

Min/Max Longitude

0 to 360(East Longitude = Positive)
Blank(Any Longitude)

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

Min/Max Latitude

90 to -90(North Latitude = Positive)
Blank(Any Latitude)

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

Min/Max Orbit

0 - 4900
Blank(Any Orbit)

The MEX orbit during which the observation was acquired.

Pointing Mode

UNK(Unknown Pointing Mode)
ALL(Any Pointing Mode)

The spacecraft pointing mode at the time of the observation.
Advanced 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). This number is used as a measure of Martian seasons. (Also known as heliocentric longitude and abbreviated Ls.)

  • 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 Phase Angle

0 - 180 - (0 = OMEGA and Sun In-Line)
Blank(Any Phase Angle)

This is the angle between the sun, the surface, and the MOC at the time the picture was obtained.

Min/Max Solar Incidence Angle

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

Derived for the center of the image, this is the angle between the Sun and a "normal" drawn perpendicular to the planet's surface at the time the image was acquired. A higher incidence angle means that a person standing on the ground would see the sun lower toward the horizon.

Min/Max Emission Angle

0 - 180(0=OMEGA Directly Overhead)
Blank(Any Emission Angle)

Measured from the center of the image, this is the angle between the MOC and a "normal" drawn perpendicular to the planet's surface. In most cases, the MOC is looking "straight down" and the emission angle is thus close to 0°.

Min/Max Slant Distance

250 - 21,000(Distance from sub-MEX point to image center, in meters)
Blank(Any Slant Distance)

This number is similar to the spacecraft altitude, but also takes into account the emission angle. If the emission angle is 0 then this number is the same as the spacecraft altitude. If the emission angle is much greater than 0, then the "slant distance" to the surface at the center of the image is also greater than the spacecraft altitude.

Min/Max Spacecraft Altitude

270 - 20,000 (in km)
Blank(Any Altitude)

The distance from the spacecraft to the surface of the reference body, measured along a line normal to the surface,

Local True Solar Time (24hr)

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 long.

Min/Max Horizontal Pixel Scale

330 - 25,100(in meters/pixel)
Blank(Any Horizontal Pixel Scale)

The horizontal resolution, in meters/pixel, at the center pixel of the observation.

Min/Max Vertical Pixel Scale

330 - 1,000,000(in meters/pixel)
Blank(Any Vertical Pixel Scale)

The vertical resolution, in meter/pixel, at the center pixel of the observation.

Stamp Layer Functions

The CRISM Stamp Layer's functions are identical to the functions of the Stamp Layer and are explained in detail on the Stamp Layer page.