Summary and Future Chances - GNSS Remote Sensing: Theory, Methods and Applications - page 258

Chapter 12
Summary and Future Chances

12.1 Status of GNSS Remote Sensing

12.1.1 Atmospheric Sensing

Ground-based together with space borne GPS radio occultation observations (Ao
2009 ) have been widely used in atmospheric and ionospheric sounding, including
sensing tropospheric precipitable water vapor (PWV), ionospheric total electron
content (TEC) and atmospheric profile information (e.g., pressure, temperature,
humidity, tropopause and ionospheric electron density), gravity waves and sporadic
E-layers as well as their variation characteristics,. For example, the dual frequency
ground GPS array could detect ionospheric response and its processes during
large geomagnetic storms (Jin et al. 2008 ). Schmidt et al. ( 2010 ) observed upper
tropospheric warming and lower stratospheric cooling using GPS RO data (2001-
2009). Meanwhile, ground GPS also observed the plasma bubbles and retrieved
reliable propagation characteristics of the depletions without assumptions about
the mapping of the depletion along magnetic field lines to large latitudinal dis-
tances, comparable with airglow data (Haase et al. 2011 ). These observations have
facilitated greater advancements in meteorology, climatology, numerical weather
model, atmospheric science and space weather (e.g., Jin et al. 2007 ; Jin and Luo
2009 ; Schmidt et al. 2010 ). Although a number of progresses in atmospheric
and ionospheric sensing have been made using ground and space-borne GNSS
observations in the past few years, they still do not satisfy actual requirements for
short-time scales and higher temporal-spatial resolution monitoring together due to
the lack of observations (Jin et al. 2006 , 2008 ; Nesterov and Kunitsyn 2011 ).