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Tip
These conditions are combined together by the logical AND operator. So a row of data is only added to the results when all the conditions match.

The data used for the examples

This is a summary of the data files used for the examples:

File	Structure	Description
temp.bufr	Image Modified	Classic radiosonde data. One message contains a vertical profile for one station with various parameters (e.g. temperature, wind etc.) on a set of pressure levels.

Extracting a single parameter

Description

Example

Filter

Results

Comments

For all the messages: extract the first non missing temperature value

Code Block
extract_data: on parameter_1: airTemperature

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By default missing values are ignored in data extraction (see option MISSING DATA)

For all the messages: extract the first (rank=1) temperature value (if missing it is ignored)

Code Block
extract_data: on parameter_1: airTemperature parameter_rank_1: 1

Image Modified

Here we explicitly asked for the first temperature value. It has a missing value in many of the messages so we have less resulting rows that in the previous example.

For all the messages: extract the first (rank=1) temperature value if it is greater than 300 K

Code Block
extract_data: on parameter_1: airTemperature parameter_rank_1: 1 parameter_operator_1: > parameter_value_1: 300

Image Modified

For all the messages: extract the first temperature value which is greater than 300 K

Code Block
extract_data: on parameter_1: airTemperature parameter_operator_1: > parameter_value_1: 300

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For station 78016: extract all the temperature values

Code Block
identifier_value: 78016 extract_data: on parameter_1: airTemperature extract_mode: all

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Extracting with a single coordinate condition

Description

Example

Filter

Results

Comments

For all the messages: extract the first temperature value which is greater than 300 K and also extract the pressure on which it occurs

Code Block
extract_data: on parameter_1: airTemperature parameter_operator_1: > parameter_value_1: 300 coordinate_condition_count: 1 coordinate_1: pressure

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Here we explicitly say the we only want the matching temperature values which appear inside a pressure block (in these messages this is always the case). By using the coordinate condition pressure will be extracted as well because the EXTRACT_COORDINATE option is On by default.

For all the messages: extract the first temperature value which is greater than 300 K and the pressure is less than 950 hPa

Code Block
extract_data: on parameter_1: airTemperature parameter_operator_1: > parameter_value_1: 300 coordinate_condition_count: 1 coordinate_1: pressure coordinate_operator_1: > coordinate_value_1: 95000

Image Modified

Here we further refined the coordinate condition.

For all the messages: extract the

(first)

temperature value on the 500 hPa pressure level

Code Block
extract_data: on parameter_1: airTemperature coordinate_condition_count: 1 coordinate_1: pressure coordinate_operator_1: = coordinate_value_1: 50000

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For station 78016: extract the temperature on the second pressure level

Code Block
identifier_value: 78016 extract_data: on parameter_1: airTemperature coordinate_condition_count: 1 coordinate_1: pressure coordinate_rank_1: 2

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Here we restricted the filter form one station (message) only and used a rank condition for the coordinate.

For station 78016: extract the temperature on the first 6 pressure levels

Code Block
identifier_value: 78016 extract_data: on parameter_1: airTemperature coordinate_condition_count: 1 coordinate_1: pressure coordinate_rank_1: 1/2/3/4/5/6

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For coordinate rank a list of values can be specified.

For station 78016: extract the temperature on the 925, 850 and 700 hPa pressure levels

Code Block
identifier_value: 78016 extract_data: on parameter_1: airTemperature coordinate_condition_count: 1 coordinate_1: pressure coordinate_operator_1: = coordinate_value_1: 92500/85000/70000

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Extracting multiple parameters

Description

Example Filter Results Comments

For all the messages: extract the first wind speed and wind direction values

Code Block
extract_data: on parameter_1: windDirection parameter_2: windSpeed

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Note
The order of the parameters in extraction must match their order of appearance in the message. Otherwise the data alignment does not work properly. In our BUFR messages `windDirection` precedes `windSpeed`, so we have to use the same ordering.

For all the messages: extract the first wind speed and wind direction values and also extract their pressure

Code Block
extract_data: on parameter_1: windDirection parameter_2: windSpeed coordinate_condition_count: 1 coordinate_1: pressure

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For all the messages: extract wind speed and wind direction values on the 500 hPa pressure level

Code Block
extract_data: on parameter_1: windDirection parameter_2: windSpeed coordinate_condition_count: 1 coordinate_1: pressure coordinate_operator_1: = coordinate_value_1: 50000

Image Modified

Multiple (nested) coordinate conditions

Task

Filter

Results

For station 78016: extract all the temperature values on standard pressure levels

Code Block

identifier_value: 78016
extract_data: on
parameter_1: airTemperature
coordinate_condition_count: 2
coordinate_1: pressure
coordinate_2: verticalSoundingSignificance
coordinate_operator_2: =
coordinate_value_2: 32

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For station 78016: extract all the temperature values on temperature significant levels where the pressure is less than 500 hPa

Code Block

identifier_value: 78016
extract_data: on
parameter_count: 1
parameter_1: airTemperature 
coordinate_condition_count: 2
coordinate_1: pressure
coordinate_operator_1: <
coordinate_value_1: 50000
coordinate_2: verticalSoundingSignificance
coordinate_operator_2: =
coordinate_value_2: 4/68

Image Modified

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Key

The data used for the examples

Extracting a single parameter

Extracting with a single coordinate condition

Extracting multiple parameters