#data [options] [data_type data_items] [data_type data_items] ...
The #data command lists the observations that will appear after each target station. Each observation is represented by a data type code (such as SD for slope distances) and one or more data items defining the fields (such as errors, classifications, and so on) that make up the observation.
The #data command may also include options defining overall characteristics of the data format. The options can be placed before or after the data items. The available options are:
grouped specifies that the data layout is as for grouped data. This is redundant if the data includes observations which force grouping (horizontal angles and distance ratios).
no_heights specifies that the instrument and target station definitions do not include a station height (it is assumed to be 0).
Each observation is represented by a data type and some data items. For example distance data may include the measured slope distance, the error in the distance, and the equipment classification of the distance. In the data definition this would look like
#data no_heights sd error equipment
and in the data block the data could be
STN1 STN2 1234.567 0.002 DI20
If an observation is unavailable then it can be replaced in the data file with a hyphen -. This is useful in a data block with more than one observation per line. For example each line may contain an angle and a distance observation. If the distance to one station is not measured then it can be replaced by a hyphen. The hyphen replaces all the data items relating to the observation. For example the data definition could specify that each line contains a horizontal angle, a slope distance, and the error of the slope distance. The definition would be
#data no_heights ha sd error
and the corresponding data block could include
STN1
STN2 0 00 00.0 1234.45 0.03
STN3 58 02 25.3 -
STN4 89 08 37.5 987.65 0.02
Here the distance from STN1 to STN3 is missing. (Note that this example the data is in grouped format because it includes horizontal angle data).
The available data types are listed in the table below.
The data type may be followed by any of the following items.
value the measurement itself. The value item can be omitted if it is the first item after the data type. In the data block, this field is read as an optional '*' (indicating a rejected observation), followed by the measurement, followed optionally by the word "error" and the error of the measurement.
error the error of the measurement. If this is not specified then current default error for the data type is used (as specified by data definition commands listed below). The units of the error in the data block is listed in the following table
date the date or date/time of the measurement formatted as for the date data definition command.
time the time of the measurement formatted as hh:mm or hh.mm.
distance_scale_error the distance scale error code for the measurement (only applies to distance data)
refraction_coefficient the refraction coefficient code for the measurement (only applies to zenith distance data)
bearing_orientation_error the bearing orientation error code for the measurement (only applies to azimuth and projection bearing data)
classification The data item is the name of a classification of the data (e.g. EQUIPMENT). This classification must already be defined in the data file by a #classification command (see below). The data block should contain the corresponding classification of the measurement (e.g. T2). See observation classifications
systematic_error The data item is the name of a systematic error. The data record contains the influence of the systematic error on the observation.
id The id of the observation. This is an integer id. It is not used by SNAP.