Advanced Target Suggestion Tutorial

 

  1. When you open up the HiRISE Image Suggestion Facility Webpage (HiWeb), you will see a bright colorful map of Mars.  This map has been created using data from Mars Orbiter Laser Altimeter (MOLA), which is an instrument on the Mars Global Surveyor.  It has collected altimetric data from the entire surface of Mars and shows the planet's highs and lows.  Blue areas on the map are low in elevation and reds are high.  The very highest spots on the planet, the tops of the volcanoes of Tharsis and Olympus Mons, are white.  The lowest area, in Hellas Planitia, is a deep purple.

 

 

 

 

  1. You also have the option of seeing maps created with other instruments, by selecting one from the top of the map.  Try looking at each of the maps.  You will find that different features are more or less clear using the various tools.  

 

These tools are:

MDIM: Mars Digital Image Models from the Viking Orbiters. Orbiters imaged the entire surface of Mars at a resolution of 150 to 300 meters, and selected areas at 8 meters. This map is a mosaic of all of the images, and provides a nice overview of the entire planet.  Large features are clearly visible, but the resolution is too poor to see smaller features like gullies or sedimentary layering.

 

 

MOC: Mars Orbiter Camera, which is onboard the Mars Global Surveyor. Both wide-angle images and narrow angle images were taken using this instrument.  Wide-angle image resolutions range from ~2 to ~15 meters/pixel. The narrow-angle lens takes more detailed photos and can image features as small as 0.5 meters (1.7 feet) across. Images from MOC are higher resolution than MDIMs, but there is less coverage of the planet.  So with MOC images, you can see smaller features much better.  The HiRISE images will be able to image even smaller features, and HiRISE will be able to take color photos.

 

 

MOLA: Mars Orbiter Laser Altimeter, which is an instrument on the Mars Global Surveyor. This tool measured the height of martian surface features like mountains and depths of valleys, producing elevation maps precise to within about 30 centimeters (1 foot) in the vertical dimension.  This is particularly useful for looking at the polar caps, seeing large canyons, impact craters and volcanoes.

 

TES: Thermal Emission Spectrometer, an instrument on the Mars Global Surveyor. This instrument studies the atmosphere and maps the mineral composition of the surface by analyzing infrared radiation, which scans for heat emitted from the surface of Mars. This instrument is used to look at the minerals on the surface of Mars and also to see if there are areas of high heat flow, like you would see in a hydrothermal region, such as Yellowstone National Park on Earth.

 

 

 

  1. Once you have looked at the various maps of Mars, select the one that helps you see the feature you are most interested in.  If you move your cursor around the map, you will see a box.  This is the area that will come up in the next page.  Move your cursor to site you are interested in and click it.  A new window will pop up with an MDIM surface image of the area.

 

 

 

  1.  Again, you have the option of selecting which map view you prefer at the bottom of the page. Turning the grid "on" will provide you with the latitude and longitude grid. 

 

 

  1. You can either click on the + and – to zoom in and out, or you can click on one of the options under "Map Scale".  If you use the plus and minus buttons, the percent zoom and resolution is to the right of the box.  You can move the image by either clicking on the arrow buttons, clicking on the image and holding the mouse button down as you drag it, or by dragging the red box in the map at the lower left to the area you want to look at. 

 

 

  1. Once you have found the area you are interested in, click on "Suggest HiRISE Target".  This window will pop up: 

 

 

 

  1. In this window you will see your zoomed-in image of Mars and a series of buttons to the left.  To the far left are two buttons, "MOC/THEMIS" and "Map Display/Suggestions".  If you click on the "MOC/THEMIS" button, it will allow to you see the more detailed images from MOC or THEMIS.  THEMIS is the Thermal Emission Imaging System, a camera on Mars Odyssey that images Mars in the visible and infrared parts of the spectrum.  This instrument is used to take photos of the planet and also to determine the distribution of minerals on the surface of Mars. The IR resolution of the instrument is 100 meters (328 feet) per pixel. Using visible imaging in five spectral bands, the experiment also takes 18-meter-resolution (59-foot) images. 

 

 

 

  1. Above is an image of this page with MOC narrow angle areas displayed. You can select to see the images by clicking on the box.  If you select "Link to webpage" in the box below, it will send you to the webpage with the photo and additional information about the camera and sunlight angles, the resolution, the orbit it was taken, and more.  Alternatively, if you select "Link to Image", a printable page with just the image will appear. 

 

 

  1. After experimenting with this, and seeing what high-resolution images have already been taken of the area using MOC and THEMIS, you can return to "Map display/Suggestions".  You can click on the button "View Suggestions" to see if anyone has already suggested the location you are interested in.

 

 

 

  1. You can find out the details about their request by clicking on the blue outline of the suggested spot.  A window similar to the one below will appear with all of the details of the request.  Close this window when you are finished and return to the window shown above.

 

 

 

  1. Clicking on "Basemap Processor" button on the left side of the window will bring up a new window where you can modify the image to help bring out some of the features.  You may see this window first, asking you to select a portion of the image to process. Click on one of the boxes to select the area.

 

 

Once you see the page below, try using the equalize button or adjusting the levels to see what happens.  You can always reset it back to the original image by pressing the reset button.  You can then save or print this modified image if you wish.  When you are finished, exit out of this window to return to the previous window. 

 

 

 

 

  1. The "Elevation Profiler" button allows you to view an elevation map of the area, create a graph of the elevation of a cross-section, and view MOC images. Click on this button and a new window will appear like the one below. By clicking on the image, it will open up in another new window that you can print, such as the one shown below.  If you want to look at an elevation profile, load either half- or full-resolution data by clicking either of the two buttons on the left, then click the "Create Profile" button.  Then click on the screen where you want the profile to start and click at the point where you want it to end.  Then click the mouse again or click the "Create Profile" button again to plot the line on the graph. Below, you can see two profiles have been created showing the topography of Olympus Mons. You can make as many profiles as you like, or press "Clear Profiles" to start over again. 

 

 

 

  1. You can also display the map using MDIM images or using the MOLA data.  By selecting "local" for elevation color, the color range from black to white is based on the elevation only within the image.  Global elevation color maintains the same color range that is representative of the entire planet, so white is the elevation of the highest places on the planet, and black is the lowest.  If you want to compare multiple locations, you will probably want to use "global" colors, but if you want to see more subtle changes in topography, use "local".  This will not affect your profiles.  You can also change the length of the X-axis to fit your profiles. 

 

 

  1. You can see the narrow and wide angle MOC images on this screen as well.  Click "Display MOC images" and select either narrow or wide.  Then you can click on the boxes to see the image. The boxes for the wide-angle MOC images represent the center of the image.  If you move your cursor over the box, you will see the full extent of the image.  You can chose to select just the image or go to the webpage, which has additional information about the image and download options.  When you are finished you can close the window and return to the "Map Display/Suggestion" page. 

 

  1. Now you can select the area that you think should be imaged. Click "Suggest HiRISE Target".  If you are a new user, you will have to create a user name and password.  Do this by clicking the "Register" button at the right of the window that pops up:

 

 

 

  1. Fill in the registration form.

 

 

 

  1. Once you have logged in, this window will appear.

 

 

 

  1. Leave this window open, but return to the "Map Display/Suggestion" page to select the area you wish to image.  Under the button "Suggest HiRISE Target" you can choose either "image footprint" or "polygon".  Image footprint will give you a parallelogram by clicking on the image and dragging the cursor or by simply clicking on the page.  If it is not in the correct place, you can drag this parallelogram to the area you wish to image.  If you chose polygon you can define the boundaries with any shape.  Click the mouse at the edges of the polygon and double-click the mouse at the end.  You have now selected the area to be imaged.  Below shows a selected area with an image footprint selected, outlined in green and yellow.

 

 

 

  1. The parameters will automatically be entered into the orange HiRISE suggestion form window under General parameters. 

 

 

 

  1. At the right side of the window is an area labeled "Your Priority".  If you are selecting a number of locations, chose which ones are the highest priority for you.  1 is low priority, and 5 is high.  Remember that not all of the suggested locations can be imaged, so chose your high priority locations carefully. 

 

 

  1. Next go to Science Justification, just below on the same window, and select a "Primary Science Theme". This allows you to chose the scientific area that best applies to the reason for your selection.  For example, if you think that the area you selected may be an interesting ancient river bed, you would select "Fluvial Processes". If you are looking at growth or recession of the polar caps, you may select "Glacial Geology" as your primary theme and "Climate Change" as your secondary theme.  This then tells us where this request should be sent.  Each science theme has a different scientist that will select the best suggestions to be imaged. 

 

Here is a brief description of what each of these scientific areas cover.  Click on the term to go to a link with more information about the scientific specialty. 

v    Climate Change: any features, deposits or landforms indicative of changing climatic regimes.

v    Eolian Processes: refers to features or processes involving wind erosion or deposition.  Examples include: dunes, wind streaks, dust devils.

v    Fluvial Processes: refers to surface and subsurface water flow processes involving the formation and subsequent development of channels, rivers or streams and the valley systems in which they flow or once flowed.  Water is critical for life as we know it, so the presence of water in streams or gullies on Mars suggests that there was water on the surface of Mars at one point.  Persistent surface and subsurface water flow could have potentially created habitable regions in the planetÕs past. 

v    Future Exploration/Landing Sites: Understanding past landing sites from orbit or to target areas of potential future landing sites for further study.

v    Geologic Contacts/Stratigraphy: refers to the description, correlation, classification of stratigraphic layers and their depositional environments. Also refers to the geologic boundaries between two different layers, surface units, materials, or features.

v    Glacial Processes: refers to the landforms, features and materials produced by glacial or ice sheet activity. Examples include: moraines, eskers, kettles, kames.

v    Hydrothermal Processes: refers to processes involving hot ( or above ambient temperature) water at or near the surface.  Many hydrothermal areas have been heated by hot magma bodies beneath the surface of the planet, such as the hot springs in Yellowstone National Park on Earth.  There may have been significant hydrothermal activity near the volcanoes or impact craters on Mars in the past. 

v    Impact Processes: refers to the processes involved in meteorite impacts and the subsequent formation of impact craters and basins and related features to the surface of the planet. 

v    Landscape Evolution: different landforms and processes that affect the overall changes in a regionÕs or landscapeÕs shape and elevation over time. Many of the features on Mars look similar to those seen on Earth, but many are quite different.  Understanding the origin of the unusual features can tell us about the history of the planet.

v    Mass Wasting Processes: refers to the movement of sediment and rock material downslope by gravitational forces.  Downslope movement may be slow as in creep and solifluction or may be rapid as in landslides, rockfalls, rockslides and debris flows.

v    Periglacial Processes: refers to landforms or features that form at the margins of former and existing ice sheets and glaciers. Environments where frost action is important and induced by a periglacial climate beyond the margin of an ice sheet.  Such landforms include: pingos, polygons, and a variety of patterned ground.

v    Polar Geology: (detailed version) studies of the polar caps.  Understanding the polar caps on Mars can help us better understand past climate changes on Mars. 

v    Seasonal Processes: refers to any processes, landforms or features that change with the season.  Examples include: the sublimation of the polar ice caps, presence of seasonal frosts, landforms or features that change shape, color or are present with the season.

v    Sedimentary/Layering Processes: refers to the deposition or erosion of sediment layers in lakes or oceans, layers formed by deposition of ash from volcanic eruptions or layers from cyclic changes in the amount of dust in the atmosphere.

v    Surface Properties: refers to understanding the physical and chemical composition of the surface. For example: the nature and abundance of rocks on the surface and the materials that comprise the surface.

v    Tectonic Processes: refers to deformation of the planets surface into fractures, lineaments, grabens and faults caused compression, shearing or expansion of the planetÕs crust by volcanic, impact or sedimentary processes.

v    Volcanic Processes: (detailed version) refers to the processes involved in volcano formation and lava emplacement on the surface of the planet.  Much of Mars is covered in volcanic rocks, and ancient lava flows can be observed over much of the planet.  Volcanoes also greatly affect the atmosphere due to the eruption of gasses, and this could have had a large impact on past climate. 

 

  1. Next, under "Science Rationale," type in a brief explanation of why you think this is an important place to collect an image. For example, you may say, "this area is a potential lake bed, and we are interested in seeing evidence of layering or platforms along the lake margins." 

 

 

  1. Next you may select specific parameters for the camera.  At the top of the HiRISE Suggestion Form, click on "Special Requests".  Here you can select the resolution of the photo you would like to take. Resolution refers to the sharpness or clarity of the image.  The lowest resolution option is 1.2 m/pix, and the highest resolution is 0.3 m/pix. For more information on Resolution and Binning, go to this page. You may be tempted to select the highest resolution, but keep in mind that there is a limit to the amount of data that can be stored, and the higher the binning (and lower resolution), the more images that can be obtained.  So you will also need to justify your reasons if you want the highest resolution and give it a priority of 1 (lowest) to 5 (highest). On this page you can also decide if you need color or stereo images. You would select "stereo needed" if you wanted two photos from two opposing angles taken of the same location.  This can then be used to calculate height or depth of a feature and make 3-D images. Here, too, you will need to provide a justification for needing it and give it a priority value.

 

 

 

  1. Next you can go on to "Seasonal Constraints" by clicking that button at the top of the window. These parameters are particularly useful if you are interested in looking at the poles, so that the surface is well lit, or if you are interested in seeing seasonal changes on Mars. If you do not know or do not care, you can leave the "Seasonal Constraints On" button unchecked. If you do want to see seasonal changes, click the square next to "Seasonal Constraints On" and you will be allowed to modify the minimum and maximum LS and the number of observations with the sliders on the right. Solar Longitude (LS) is the position of Mars relative to the Sun measured in degrees from the vernal equinox. This number is used as a measure of martian seasons: Northern Spring/Southern Autumn start at 0¡, Northern Summer/Southern Winter start at 90¡, Northern Autumn/Southern Spring start at 180¡, and Northern Winter/Southern Summer begin at 270¡. For example, if you wanted to take an image at summer and winter, you would select 2 observations, putting the minimum LS at 90 and the maximum at 270.

 

Here is a brief description of the terms used for the seasons:

¯    Vernal Equinox: start of Spring in the northern hemisphere, most sunlight falls directly on the equator

¯    Winter Solstice: when the north pole is in continuous darkness, and the south pole is in continuous daylight.

¯    Summer Solstice: when the sun falls on the north pole and it is in continuous daylight, and the south pole is in continuous darkness.

¯    Autumnal Equinox: start of fall in the northern hemisphere, sun falls directly on the equator. 

 

 

 

 

  1. Finally, when you have finished, you can click "Submit" at the bottom of the window.  If any parameters are missing, you will be alerted.

 

 

  1. You can later edit your suggestions by returning to the HiRISE Target Suggestion webpage and going to the third page, where you will see the "Login to Edit Suggestions" button at the top left side of the screen.

 

 

 

Thank you for suggesting a target! When the image is taken you will be notified by email and will be able to view the collected images at a link provided at: http://marsoweb.nas.nasa.gov/hirise.