NRT availability monitoring
Near real-time availability monitoring
The main aim of the near-real time availability monitoring is to provide information on data coverage, data timeliness and used data reception routes for key satellite data types from major international satellite agencies commonly used in NWP:
- MW and IR sounders (L1b radiances)
- IR hyperspectral sounders (L1b radiances)
- MW imagers (L1b radiances)
- AMVs from geostationary and polar orbiting satellites
- Wind vectors from scatterometers
- Wind speed from altimeters
- For monitoring of radio-occultation data, please refer to the ROM-SAF NRT monitoring pages.
The information on NRT data availability is structured into three parts:
This availability monitoring is currently being developed as part of the CDOP-3 activities (2017 onwards). Therefore, the corresponding web-pages are still under construction with the data coverage monitoring being set up first and timeliness monitoring following as a second step in the near future. The information provided currently on these pages is not complete yet in terms of availability of all plot types and number of contributing centres, and page contents will be extended and adapted as more complete monitoring becomes available. Comments and suggestions on contents and display are welcome, please contact the NWP SAF User Helpdesk.
Additionally, the NWP SAF NRT quality monitoring also provides information on data volumes as time series.
The geographical coverage plots allow a quick overview of currently available data by displaying the horizontal coverage within the four last 6 hour windows (i.e. the last 24 hours) grouped by main data and instrument types. This is useful particularly in case of data outages or data transfer problems and allows faster tracking of underlying problems.
Data coverage is provided by several NWP centres to allow comparison of received data. From Q3 2017 it is anticipated that NRT data availability and timeliness statistic from the Met Office and DWD will also be made available.
|Available Q3 2017 (see above)||data coverage||data coverage||data coverage|
It is becoming ever more important for NWP centres to judge whether the timeliness of the data is sufficient to meet the requirements of their applications and particularly with the move towards use of rapid update very short range high resolution forecasting systems at several centres, information on data transfer times is important for defining the increasingly strict cut-off times.
The data transfer timeliness is monitored for the same data types, but in addition separately for the different satellite agencies and satellite platforms as data production and transmission schedules may differ. It analyzes and monitors the delay between observation time and the data reception in data banks. The timeliness statistics are made available for the most recent data as well as in the form of timeseries to allow checking for the stability of data reception. As for data coverage, there will be more than one centre providing these statistics, so that cross-checks on delay times are possible in case of arising issues.
Satellite data are disseminated using different transmission channels. The channels used by the centres contributing to the NWP SAF NRT availabiliy monitoring are summarized on the data reception routes page. This provides information on how the different satellite data types can be accessed and received and additionally can be useful background information to judge possible systematic differences in timeliness experienced at different centres.