The Close-Up View of Search Area page is the second step in locating MGS data products. The map on this page is an enlarged view of the 30 by 30 degree area you selected on the Search page.
The map is marked with latitude and longitude lines every 5 degrees. It also shows the locations of MGS data products that occur in the area, either as points or ground tracks. The product locations are color-coded by data type according to the legend.
You may limit your search to include only products of a certain type (MOLA and TES products, for example). You may also choose to include only products from a certain orbit range. Use the checkboxes labeled Data products and orbits to set these constraints.
MGS data product types are:
- MOC-NA (Mars Orbiter Narrow-Angle Camera)
- MOC-WA (Mars Orbiter Wide-Angle Camera)
- MOLA (Mars Orbiter Laser Altimeter)
- TES (Thermal Emission Spectrometer)
- MAG (Magnetometer)
- ER (Electron Reflectometer)
- ACC (Accelerometer)
- RS (Radio Science)
MGS pre-mapping mission phases are equivalent to these orbits:
- AB-1 (aerobraking phase 1): 1-201
- SPO-1 (science phasing orbit 1): 202-268
- SPO-2 (science phasing orbit 2): 329-573
- AB-2 (aerobraking phase 2): 574-1284
- Transition to circular mapping orbit: 1285-1683
To complete your search, select a latitude/longitude area in the same way as before, either:
The result of your search will be a new page listing all the products that fall into the 5 by 5 degree area and that match your criteria for data products and orbits. The listing will include links to the data files so that you can display or download the data. It will also include links to "browse" versions of the data products if they exist. Click the Help button on the Results page for more information.
To go back to the beginning and choose a different area of the global map, click the button labeled Start Over.
The 30 by 30 degree map is from the Mars Digital Image Model (MDIM) shaded relief data from the Viking mission. No attempt was made to reproject the MDIMs using an updated Mars control net or new prime meridian. At the scale of the map on this page, the difference is only a few pixels. Colored lines and points are overlain on this map to show the locations of MGS products. The product locations were plotted a little differently for each data set. In some cases products are included in the search database even though they do not appear on the maps due to subsampling or other plotting restrictions. See details below. Also, where multiple products coincide on the map, the underlying ones may be hidden.
MOLA
To show the approximate ground track of MOLA observations, each MOLA orbit was subsampled to every 50th observation, and lines were drawn connecting those points. Obvious discontinuities were eliminated. Therefore it is possible that a search may turn up some MOLA products in the results listing that do not appear on the map.
MOC
The center point of each narrow-angle MOC image was plotted as a point. Wide-angle MOC images are not shown on the map because they are often so wide as to cover the entire area. Wide-angle images do appear in the results listing, however, if their center points occur in the selected area.
TES
To show the approximate ground track of TES observations, the observations from TES detector 2 were subsampled every 0.25 degree, and further restricted to those observations where the spacecraft altitude was less than 1000 km. These locations were plotted as points. However, all TES products are included in the search database. Therefore it is possible that a search may turn up some TES products in the results listing that do not appear on the map.
ACC
The spacecraft ground track was computed using SPICE data for the times during which Accelerometer observations were obtained, and plotted as lines.
MAG/ER
The spacecraft ground track was computed using SPICE data for the times during which MAG and ER data were acquired, limited to times when the spacecraft altitude was less than 350 km, and plotted as lines. The search database is also limited to products acquired at altitudes below 350 km.
RS
The projected surface point of occultation was plotted as a point for each Radio Science observation. These data are from the Radio Science occultation summary files in the RS/OCS subdirectory.