All of the questions below are linked to descriptive answers in this chapter of the Giovanni-3 Online Users Manual regarding the Giovanni-3 MISR Monthly Level 3 Data instance. Note that there is also a MISR Level 3 Daily Data Giovanni instance, to which most of these questions also apply. Click the question of interest.
1. What does MISR stand for? What satellite is the MISR instrument on?
2. For what time period is MISR data available in Giovanni?
3. What version of MISR data are currently provided in Giovanni-3?
4. What MISR data types are available?
5. What MISR data parameters are currently available in Giovanni-3?
6. How are the data organized? What is the spatial resolution of the data?
7. What are the current data analysis and visualization options for MISR data in this Giovanni-3 instance?
8. How is the area of intererest selected for Giovanni-3 MISR data?
9. How is the time period of interest selected for Giovanni-3 MISR data?
10. Are there any limits on the region or time period of interest that can be selected?
11. Are there any limits on the number of parameters that can be plotted?
12. What are the various plotting preference options for MISR data in Giovanni-3?
13. What is MISR aerosol data actually useful for?
14. What is the MISR aerosol data product in Giovanni most sensitive to?
What does MISR stand for? What satellite is the MISR instrument on?
MISR stands for the Multi-Angle Imaging SpectroRadiometer. MISR is an instrument on the Earth Observing System TERRA satellite.
For what time period is MISR data available in Giovanni?
MISR data is currently available from March 2000 to August 2006. Newer data will become available in the Giovanni system as it becomes available from the data provider. MISR data is obtained from the NASA Langley Research Center (LARC).
What version of MISR data are currently provided in Giovanni-3?
The MISR data currently available in the Giovanni system is Version 4 (note the data product suffix "004".) See the MISR data page at LaRC for information on data processing and data versions.
What MISR data types are available?
The MISR data types available in Giovanni are Level 3 monthly global data. The link below provides more information about the MISR Level 3 data product.
MISR Level 3 Imagery Overview
What MISR data parameters are currently available in Giovanni-3?
Currently four MISR data parameters are available in Giovanni-3. The MISR: Level 2 Aerosol Retrieval (PDF) Algorithm Theoretical Basis Document (ATBD) describes how these data products are calculated. Level 3 MISR data are created from the Level 2 satellite swath data using spatial and temporal averaging methods.
How are the data organized? What is the spatial resolution of the data?
The MISR monthly data are organized as monthly data files. [MISR daily data are organized as daily data files.] The spatial resolution of the data is 0.5° x 0.5°. The MISR Level 3 global data products are plotted on a rectangular grid that is 0.5° latitude by 0.5° longitude. The upper left corner of the grid is located at 90.0 N and -180.0 W. The center of the upper left corner grid cell is at 89.75 N, -179.75 W.
What are the current data analysis and visualization options for MISR data in this Giovanni-3 instance?
The following data analysis and visualization options can be used with the MISR Monthly Level 3 data.
How is the area of interest selected for Giovanni-3 MISR data?
The spatial area of interest can be selected by either of the two methods described below
Java applet map: The Java applet map can be utilized to "click and drag" a selection box to designate the spatial area of interest.
Geographic coordinates: The geographic coordinates of the corners of the spatial area box can be input individually. This method can be used if Java is not enabled. Note that decimal and not degree (seconds and minutes) coordinates must be entered.
How is the time period of interest selected for Giovanni-3 MISR data?
The start month and year and the end month and year for the analysis are selected using the calendrical drop-down menus on the Giovanni interface page. Error messages will be generated if the submitted selections for month and year do not correspond to the data set time range, or if the end month and year precede the start month and year.
Are there any limits on the region or time period of interest that can be selected?
The selected time-period must correspond to a time-period occuring within the time range of MISR mission data. If the start date or end date is not in the time range, an error will be generated and data processing will not be possible.
Are there any limits on the number of parameters that can be plotted?
Yes, there is currently only one parameter available, so this is the only parameter that can be plotted.
What are the various plotting preference options for MISR data in Giovanni-3?
The plotting preference options are described in the Plot Preferences chapter of the Giovanni-3 Online Users Manual. After the initial output has been generated, the temporal and spatial ranges (constraints) and plotting preferences can be changed, and a new output generated, using the "Submit Refinements" button.
What is MISR aerosol data actually useful for?
MISR data makes it possible to determine global aerosol amounts with unprecedented accuracy, and to estimate particle size and composition. MISR data can be used to distinguish the amount and type of aerosols, including both natural and anthropogenic aerosols.
What is the MISR aerosol data product in Giovanni most sensitive to?
The MISR aerosol data product (aerosol optical depth) detects smoke aerosols, dust aerosols, and anthropogenic aerosols, such as pollution haze composed of sulfur aerosols and soot. Larger particles such as dust absorb more strongly at the 555nm wavelength than smaller particles, so dust storm aerosols will tend to saturate this wavelength more than pollution aerosols.