Data file formats

This section provides an overview of the file formats supported by Source. Table 5 lists the supported time-series data file formats. Raster data file formats are listed in Table 6. Several GIS, graphics and other formats that are also recognised by Source are listed in Table 7 but are not otherwise described in this guide. 

Table 5. Text-based time-series data file formats

Table 6. Text-based raster data file formats

Table 7. Other supported file formats

Annual stochastic time series

The .AR1 format contains replicates of annual time-series data generated using the AR(1) stochastic method. The file format is shown in Table 8. This format is not the same as the AR(1) format (.GEN) generated and exported by the Stochastic Climate Library.

Table 8. AR1 data file format

where:

desc is a title describing the collection site

nypr is the number of years per replicate

nr is the number of replicates

rn is the replicate number in the range 1..nr

value is one of the nypr data points per row for the replicate, to three decimal places.

ESRI ASCII grids

The .ASC format is a space delimited grid file, with a 6 line header as shown in Table 9. Values are not case sensitive and arranged in space delimited rows and columns, reflecting the structure of the grid. Units for cell size length depend on the input data, and could be either geographic (eg degrees) or projected (eg metres, kilometres). Units are generally determined by the application, with metres (m) being common for most TIME-based applications. For a file format description, refer to:

http://resources.esri.com/help/9.3/arcgisengine/com_cpp/gp_toolref/spatial_analyst_tools/esri_ascii_raster_format.htm

Arcinfo grid coverages can be converted to .ASC files using ESRI’s GRIDASCII command. ASC files can be imported into ArcGIS using the ASCIIGRID command.

Table 9. .ASC data file format

where:

nc is the number of columns

nr is the number of rows

xref is either XLLCENTER (centre of the grid) or XLLCORNER (lower left corner of grid)

yref is either YLLCENTER (centre of the grid) or YLLCORNER (lower left corner of grid)

(x,y) are the coordinates of the origin (by centre or lower left corner of the grid)

size is the cell side length

sentinel is a null data string (eg -9999)

value is a data point. There should be nc × nr data points.

AWBM daily time series

An AWBM daily time-series format file (.AWB) is an ASCII text file containing daily time-series data formatted as shown in Table 10. Dates (the year and month) were optional in the original AWBM file format, but are not optional in the format used in Source.

Table 10. AWB data file format

where:

ndays is the number of days in the month (28..31)

value is the data point corresponding with a given day in the month (ie. ndays columns)

year is the year of observation (four digits)

month is the month of observation (one or two digits).

SWAT BSB time series

A .BSB is a line-based fixed-format file, typically used by applications written in FORTRAN. The header line gives the fields for the file with subsequent lines providing data for each basin to be used for each time-step. The format is shown in Table 11. For more details refer to the SWAT manual.

Table 11. .BSB data file format

where:

id is the basin identifier (both SUB and the id are text, left-aligned)

gis unknown (integer, right-aligned, eg. "1")

year unknown (integer, right-aligned, eg. "0")

area is the basin area in square kilometers (real, right aligned, eg "1.14170E+02")

precip is the basin precipitation in millimetres (real, right aligned, eg "1.2000").

BOM 6 minute time series

A .BSM (also .PLUV) is a fixed-format file, typically supplied by the Australian Bureau of Meteorology for 6 minute pluviograph data. The file has two header lines (record types 1 and 2) followed by an arbitrary number of records of type 3. The formats of record types 1..3 are shown in Table 12, Table 13 and Table 14, respectively.

All fields in .BSM files use fixed spacing when supplied, but Source can also read spaced-separated values.

Rainfall data points:

• Each row of data contains all of the observations for that day;
• The number of observations for a day depends on the observation interval. For example, if the observation interval is 6 minutes, there will be 24×60÷6=240 observations (raini fields) in each row of data;
• Each rain field is in FORTRAN format F7.1 (a field width of seven bytes with one decimal place);
• Assuming that observations are numbered from 1..n, the starting column position of any given raini field can be computed from 14+7×i;
• The unit of measurement is tenths of a millimetre (eg. a rainfall of 2 mm will be encoded as "20.0").
• Values are interpreted as follows:
  • 0.0 means there was no rain during the interval.
  • a positive non-zero value is the observed rainfall, in tenths of a millimetre, during the interval.
  • If there is zero rain for the whole day, no record is written for that day.

Missing data:

• A sentinel value of -9999.0 means that no data is available for that interval;
• A sentinel value of -8888.0 means that rain may have fallen during the interval but the total is known only for a period of several intervals. This total is entered as a negative value in the last interval of the accumulated period. For example, the following the following pattern would show that a total of 2 millimetres of rain fell at some time during an 18-minute period: -8888.0-8888.0 -20.0
• If an entire month of data is missing, either no records are written or days filled with missing values (-9999.0) are written. No attempt is made to write dummy records if complete years of data are missing.

Example file

61078 1

61078 2 WILLIAMTOWN RAAF

61078 19521231 .0 .0 .0 [etc., 240 values]

61078 1953 1 1 .0 .0 .0 [etc., 240 values]

61078 1953 1 3 .0 .2 .0 [etc., 240 values]

61078 1953 115 .0 .0 .2 [etc., 240 values]

61078 1953 118 .0 .0 .0 [etc., 240 values]

61078 1953 212 .0 .0 .0 [etc., 240 values]

61078 1953 213 .0 .0 .0 [etc., 240 values]

61078 1953 214 .0 .0 .0 [etc., 240 values]

61078 19521231 .0 .0 .0 [etc., 240 values]

61078 19521231 .0 .0 .0 [etc., 240 values]

The following notes are taken from the Bureau of Meteorology advice:

• All data available in the computer archive are provided. However very few sites have uninterrupted historical record, with no gaps. Such gaps or missing data may be due to many reasons from illness of the observer to a broken instrument. A site may have been closed, reopened, upgraded or downgraded during its existence, possibly causing breaks in the record of any particular element.
• Final quality control for any element usually occurs once the manuscript records have been received and processed, which may be 6-12 weeks after the end of the month. Thus quality-controlled data will not normally be available immediately, in "real time".

Table 12. .BSM data file format (record type 1)