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Estimating zenith tropospheric delays from BeiDou navigation satellite system observations.

Xu A, Xu Z, Ge M, Xu X, Zhu H, Sui X - Sensors (Basel) (2013)

Bottom Line: The precise orbits and clocks are generated from a tracking network with most of the stations in China and several stations around the world.The derived ZTDs are compared with that estimated from GPS data using the final products of the International GNSS Service (IGS).The comparison shows that the bias and the standard deviation of the ZTD differences are about 2 mm and 5 mm, respectively, which are very close to the differences of GPS ZTD estimated using different software packages.

View Article: PubMed Central - PubMed

Affiliation: School of Geomatics, Liaoning Technical University, Fuxin 123000, China. xu_ag@126.com

ABSTRACT
The GNSS derived Zenith Tropospheric Delay (ZTD) plays today a very critical role in meteorological study and weather forecasts, as ZTDs of thousands of GNSS stations are operationally assimilated into numerical weather prediction models. Recently, the Chinese BeiDou Navigation Satellite System (BDS) was officially announced to provide operational services around China and its neighborhood and it was demonstrated to be very promising for precise navigation and positioning. In this contribution, we concentrate on estimating ZTD using BDS observations to assess its capacity for troposphere remote sensing. A local network which is about 250 km from Beijing and comprised of six stations equipped with GPS- and BDS-capable receivers is utilized. Data from 5 to 8 November 2012 collected on the network is processed in network mode using precise orbits and in Precise Point Positioning mode using precise orbits and clocks. The precise orbits and clocks are generated from a tracking network with most of the stations in China and several stations around the world. The derived ZTDs are compared with that estimated from GPS data using the final products of the International GNSS Service (IGS). The comparison shows that the bias and the standard deviation of the ZTD differences are about 2 mm and 5 mm, respectively, which are very close to the differences of GPS ZTD estimated using different software packages.

No MeSH data available.


Related in: MedlinePlus

Satellite visibilities in percentage of time for the local network. The GEOs are observed all the time, for IGSO and MEO the averaged visible windows are 73% and 33%, respectively. For GPS satellites the averaged visible time is about 25%.
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f3-sensors-13-04514: Satellite visibilities in percentage of time for the local network. The GEOs are observed all the time, for IGSO and MEO the averaged visible windows are 73% and 33%, respectively. For GPS satellites the averaged visible time is about 25%.

Mentions: The special constellation of the BDS regional system leads to a very different satellite visibility from the GPS system, as most of the satellites are GEOs and IGSOs. Figure 3 shows the percentage of time each satellite can be observed by the local network. The GEO satellites are observed all the time, as their movement in the sky is very slight. The IGSO satellites can be observed 73% over time, because they are limited in a narrow longitude zone. For BDS MEOs, the averaged visible window is about 33%, larger than that for GPS satellites of about 25%. Obviously, most of the transmitting paths do not change (GEO), or do not change very much (IGSO). Therefore, satellite distribution in sky might have a very strong impact on ZTD estimation. In general, satellites should be distributed zenith-symmetrically and evenly for retrieving the most precise ZTDs.


Estimating zenith tropospheric delays from BeiDou navigation satellite system observations.

Xu A, Xu Z, Ge M, Xu X, Zhu H, Sui X - Sensors (Basel) (2013)

Satellite visibilities in percentage of time for the local network. The GEOs are observed all the time, for IGSO and MEO the averaged visible windows are 73% and 33%, respectively. For GPS satellites the averaged visible time is about 25%.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3673097&req=5

f3-sensors-13-04514: Satellite visibilities in percentage of time for the local network. The GEOs are observed all the time, for IGSO and MEO the averaged visible windows are 73% and 33%, respectively. For GPS satellites the averaged visible time is about 25%.
Mentions: The special constellation of the BDS regional system leads to a very different satellite visibility from the GPS system, as most of the satellites are GEOs and IGSOs. Figure 3 shows the percentage of time each satellite can be observed by the local network. The GEO satellites are observed all the time, as their movement in the sky is very slight. The IGSO satellites can be observed 73% over time, because they are limited in a narrow longitude zone. For BDS MEOs, the averaged visible window is about 33%, larger than that for GPS satellites of about 25%. Obviously, most of the transmitting paths do not change (GEO), or do not change very much (IGSO). Therefore, satellite distribution in sky might have a very strong impact on ZTD estimation. In general, satellites should be distributed zenith-symmetrically and evenly for retrieving the most precise ZTDs.

Bottom Line: The precise orbits and clocks are generated from a tracking network with most of the stations in China and several stations around the world.The derived ZTDs are compared with that estimated from GPS data using the final products of the International GNSS Service (IGS).The comparison shows that the bias and the standard deviation of the ZTD differences are about 2 mm and 5 mm, respectively, which are very close to the differences of GPS ZTD estimated using different software packages.

View Article: PubMed Central - PubMed

Affiliation: School of Geomatics, Liaoning Technical University, Fuxin 123000, China. xu_ag@126.com

ABSTRACT
The GNSS derived Zenith Tropospheric Delay (ZTD) plays today a very critical role in meteorological study and weather forecasts, as ZTDs of thousands of GNSS stations are operationally assimilated into numerical weather prediction models. Recently, the Chinese BeiDou Navigation Satellite System (BDS) was officially announced to provide operational services around China and its neighborhood and it was demonstrated to be very promising for precise navigation and positioning. In this contribution, we concentrate on estimating ZTD using BDS observations to assess its capacity for troposphere remote sensing. A local network which is about 250 km from Beijing and comprised of six stations equipped with GPS- and BDS-capable receivers is utilized. Data from 5 to 8 November 2012 collected on the network is processed in network mode using precise orbits and in Precise Point Positioning mode using precise orbits and clocks. The precise orbits and clocks are generated from a tracking network with most of the stations in China and several stations around the world. The derived ZTDs are compared with that estimated from GPS data using the final products of the International GNSS Service (IGS). The comparison shows that the bias and the standard deviation of the ZTD differences are about 2 mm and 5 mm, respectively, which are very close to the differences of GPS ZTD estimated using different software packages.

No MeSH data available.


Related in: MedlinePlus