The SILO Patched Point Dataset (PPD)
What is the PPD |PPD example |Quick help
What is the PPD?
The Patched Point Dataset is a dataset containing daily rainfall, minimum and maximum temperatures, radiation, evaporation and vapour pressure.It combines original Bureau measurements for a particular meteorological station with infilling of any gaps in the record using the interpolation methods discussed here on this website. The PPD would typically be used when an analysis or simulation is needed quite close to an historic meteorological station. If however, an analysis is required for a location which has no meteorological station nearby, or an areal estimate for a region is required; then the Data Drill is the more relevant product.
The SILO Patched Point Dataset (PPD) is a daily meteorological data set, that presents daily weather records for 4650 Bureau of Meteorology recording stations around Australia. It is a daily semi-synthetic data set with no missing data values. These data are:
| 1st January, 1889 - 31st December 1956 | 1st January 1957 to present | |
| daily rainfall | measured and patched | measured and patched |
| minimum and maximum temperature | daily averages | measured and patched |
| radiation | daily averages | calculated from cloud oktas and incoming radiation |
| evaporation | daily averages | pan evaporation measured and patched from 1970 |
| vapour pressure | daily averages | calculated from 9am wet and dry bulb temperatures and pressure. |
Daily rainfall records exist back to the 19th century, whereas records for other variables before 1957 have not as yet been computerised from the paper archives. Daily or other longer term averages are used as a substitute.
Biophysical simulation models typically require continous daily meteorological data. The SILO PPD fills in data which is missing from observed records, with data from interploated surfaces i.e. effectively nearby stations assist in providing value estimates for gaps in the meteorological record. An example of this process is shown below:
PPD example
The first table shows a missing data problem, typical of many stations. This station has never reported radiation or vapour pressure.
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DERM has interpolated the available daily and monthly weather data at a 5 km spatial resolution
across Australia, allowing a mathematical estimate of each weather variable to be obtained for all stations on a daily basis. These
data are used to fill the gaps in the observed data. Single point interpolated data sets from 1889 to present are available for each 5 km pixel
across Australia from the
Data Drill web page
The following table shows the above measured data combined with the interpolated data:
| yyyy | mm | dd | max temp deg C | source code | min temp deg C source | source code | rain mm | source code | evaporation mm | source code | radiation MJ /sq m/day | source code | vapour pressure hPa | source code |
| 1982 | 3 | 18 | 27.0 | 0 | 15.7 | 0 | 0.0 | 0 | 2.8 | 0 | 21.0 | 25 | 19.0 | 25 |
| 1982 | 3 | 19 | 26.3 | 0 | 14.7 | 0 | 0.0 | 0 | 5.4 | 0 | 21.0 | 25 | 18.0 | 25 |
| 1982 | 3 | 20 | 26.5 | 25 | 16.5 | 25 | 0.0 | 0 | 4.2 | 25 | 17.0 | 25 | 19.0 | 25 |
| 1982 | 3 | 21 | 27.0 | 25 | 16.5 | 25 | 0.0 | 0 | 3.6 | 25 | 14.0 | 25 | 19.0 | 25 |
| 1982 | 3 | 22 | 27.0 | 25 | 16.0 | 25 | 0.0 | 0 | 4.2 | 25 | 20.0 | 25 | 20.0 | 25 |
| 1982 | 3 | 23 | 27.1 | 0 | 15.0 | 25 | 0.0 | 0 | 7.0 | 0 | 22.0 | 25 | 19.0 | 25 |
| 1982 | 3 | 24 | 26.1 | 0 | 13.8 | 0 | 0.0 | 0 | 6.8 | 0 | 16.0 | 25 | 19.0 | 25 |
| 1982 | 3 | 25 | 28.2 | 0 | 13.3 | 0 | 0.0 | 0 | 4.0 | 0 | 21.0 | 25 | 17.0 | 25 |
| 1982 | 3 | 26 | 29/0 | 0 | 13.4 | 0 | 0.0 | 0 | 6.2 | 0 | 20.0 | 25 | 19.0 | 25 |
| Bureau of Meteorology measurement (code = 0) | ||||||||||||||
| DERM interpolation (code = 25) | ||||||||||||||
All data have a code attached to show its source, here 0 indicates a BoM measurement, 25 indicates a DERM interpolation.
Quick help.
To navigate around the PPD, use the menus below in the bottom panel. In general, you need to select a station using the Find a PPD station... menu.
Next, you probably need to look at data quality issues in the Get some details... menu.
Finally, using the Get/Order PPD and other data... menu, order some PPD and other datasets,
The other menu contains some links that might be of interest to you.
Send mail to author with questions or comments about this web site.
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