**3. The data source, methodology, and roadmap**

The collected data from multiple remote sensing instruments is trustworthy; this way of the data collection has challenged the existing methods (according to the published research works), especially when it comes to the data reliability.

Throughout the research, GIOVANNI is the core of research data collection; relying on MERRA-2 (in most cases). MERRA-2 is a remote sensing model which assimilates data from various remote sensors as well different ground aerosol robotic networks (AERONETs).

Additional software tools, such as Arc GIS, have been utilized to scientifically present the results, but the statistics was done at the level of GIOVANNI web browsing [28–31].

**Figure 3.** *The research roadmap.*

*An Analysis of Remote Sensing Data to Evaluate the Problem of Atmospheric Aerosol… DOI: http://dx.doi.org/10.5772/intechopen.99377*

### **3.1 The research data source and roadmap**

The rough roadmap that was utilized to collect data and generate the results presented in this research is generalized and shown in **Figure 3**.

Different data types are available in various forms and formats: time averaged maps, scatter plots, time series, etc. In this research, both time averaged map based and time series data has been collected from GIOVANNI platform.

The collected data is then input to the analysis by the help of the software tools: ArcGIS/Arc Map to get the presentable map-based results; Origins, to generate different plots of results as functions of time.

That means that even though some results can directly be visualized online by the help of GIOVANNI, all the results presented in this research article have been further handled by additional software tools such as Arch GIS and Origins.

Microsoft Excel helps the research to do some necessary calculations, and elaborate the table-based results. Finally, a discussion is made on basis of the original results, in comparison with the existing literature review.

Thus, as seen in **Figures 3** and **4**, GIOVANNI is a bridge as an online platform designed by NASA Goddard Space Flight Center, to collect raw data from different satellites and remote sensors, the most notable are illustrated in **Figure 4**.

Though the remote sensed data can be collected from the most documentable remote sensors such as the Moderate-resolution Imaging Spectro-radiometer (MODIS), it has been challenging to directly detect dust from MODIS [32]. Therefore, the remote sensing model MERRA-2, an online model which directly assimilates the remote sensing data from the AERONETS, the MODIS and the advanced very high-resolution radiometer, AVHRR [32].

For the quality of data collected via GIOVANNI, data from different sources can be a good solution to the data reliability. For example, MERRA-2 is a model which treats the data from different sources, as earlier mentioned in this sub-section.

**Figure 4.** *A multi-sensor aerosol data bridge: GIOVANNI.*
