Nitrogen oxide estimation downstream of a selective catalytic reduction catalyst

A dosing control system comprising:

• a selective catalytic reduction (SCR) analysis module that estimates ammonia (NH3) stored by an SCR catalyst, a maximum NH3 storage capacity of said SCR catalyst, and a nitrogen oxides (NOx) measurement for a first NOx sensor located downstream of said SCR catalyst;
• a dosing management module that controls dosing agent injection into an exhaust system upstream of said SCR catalyst based on said maximum NH3 storage capacity and said NH3 stored;
• an adjustment module that outputs an adjusted estimate of said NOx measurement based on said estimate of said NOx measurement, cross-sensitivity of said first NOx sensor, and a delay period for exhaust flow between a second NOx sensor located upstream of said SCR catalyst and said first NOx sensor;
• and
• an error module that selectively adjusts at least one of said NH3 stored and said maximum NH3 storage capacity based on a difference between said adjusted estimate and NOx measured by said first NOx sensor.