As mentioned in Section 2.8.4, “Mobile-source processing”, there are three programs specific to processing on-road mobile sources using MOBILE6. This processing is performed using the Mbsetup, Premobl, and Emisfac programs, which prepare the meteorology data and other SMOKE inputs for using the inventory with the MOBILE6 program, and compute emission factors that are needed when the on-road inventory includes VMT instead of, or in addition to, emissions. These programs are discussed in detail in Section 6.8, “Mbsetup”, Section 6.12, “Premobl”, and Section 6.4, “Emisfac”.
The Mbsetup program performs the following steps needed for MOBILE6 processing:
Group reference counties
Set up for the user-defined spatial and temporal averaging approach for meteorology data
Assign the speed profiles to the sources
Create the speed summary file
In MOBILE6 processing, the Premobl program handles the step:
Process the meteorology data for use by MOBILE6
Finally, the Emisfac program addresses the following step:
Compute the criteria and toxics emission factors using MOBILE6
The following sections explain the concepts involved with these processing steps in more detail.
The first major task for the Mbsetup program is to set the reference counties (defined in Section 2.8.4.7, “Reference counties”). To do this, it reads the user-defined county cross-reference file (MCREF). This file assigns a reference county to each county in the inventory. When reading MCREF, SMOKE checks that all state and county FIPS codes in the file are integer values (no nonnumeric characters). Next, it looks
for any duplicate inventory counties and gives an error message if any are found. Mbsetup will ignore any inventory counties that are not inside the grid or do not have any VMT data. Mbsetup also makes sure that all valid inventory counties (i.e., those that are inside the grid and have VMT data) have been assigned
a reference county.