@inbook{74314, author = {ECMWF}, title = {IFS Documentation CY28R1 - Part II: Data Assimilation - Chapter 9 only}, abstract = {
Chapter 9 Observation processing'
}, year = {2004}, journal = {IFS Documentation CY28R1}, number = {2}, month = {2004}, publisher = {ECMWF}, url = {https://www.ecmwf.int/node/9196}, doi = {10.21957/iz80xsg8w}, note = {Operational implementation 9 March 2004
}, language = {eng}, }