SNO

Coldest Ocean

Site Cal/Val

Methods Introduction

To monitor the stability of Advanced Microwave Radiometer (AMR) on Jason 2 satellite, the AMR measurements are compared with measurements from the different microwave radiometers on different satellites using different methods, such as Simultaneous Nadir Overpasses (SNOs), coldest ocean, site Cal/VAL etc.

Advanced Microwave Sounding Unit (AMSU) is a cross-track scanning radiometer on board Metop-A and is fully calibrated using an on-board blackbody and deep space views. Both AMSU and AMR have the 23.8GHz channel, although the 34GHz channel on AMR does not exactly match the 31GHz channel of AMSU. The AMR and AMSU measurements at 23.8GHz and 34GHz are used to evaluate AMR's stability. The comparison between AMR and AMSU are performed using two methods: comparison at SNOs and comparison at the coldest part of the ocean with the coldest brightness temperatures (BT). Work has also been done to monitor AMR at selected CAL/VAL sites.

Double Frequency Microwave Radiometer (DFMR) is a two channel frequency radiometer on board SARAL/AltiKa and EnviSAT. Both AMR and DFMR have 23.8 GHZ channel. The could liquid water channel of AMR is 34 GHZ, different from the DFMR 37 GHZ. The comparison of AMR with DRMR are performed using SNOs method and Coldest Ocean method.