+

+ +

+

Unit conversion¶

+

New in version 5.0.0.

+

Convert between various distance, angular and time units.

+ ++++ + + + + + + + + + + + + + + +

Alias	unitconvert
Domain	2D, 3D or 4D
Input type	Any
Output type	Any

+

There are many examples of coordinate reference systems that are expressed in +other units than the meter. There are also many cases where temporal data +has to be translated to different units. The unitconvert operation takes care +of that.

+

Many North American systems are defined with coordinates in feet. For example +in Vermont:

+

+proj=pipeline
++step +proj=tmerc +lat_0=42.5 +lon_0=-72.5 +k_0=0.999964286 +x_0=500000.00001016 +y_0=0
++step +proj=unitconvert +xy_in=m +xy_out=us-ft
+

+

+

Often when working with GNSS data the timestamps are presented in GPS-weeks, +but when the data transformed with the helmert operation timestamps are +expected to be in units of decimalyears. This can be fixed with unitconvert:

+

+proj=pipeline
++step +proj=unitconvert +t_in=gps_week +t_out=decimalyear
++step +proj=helmert +epoch=2000.0 +t_obs=2017.5 ...
+

+

+

Parameters¶

+

++xy_in=<unit> or <conversion_factor>¶: Horizontal input units. See Distance units and Angular units +for a list of available units. <conversion_factor> is the conversion factor +from the input unit to metre for linear units, or to radian for angular +units.
+

+ +

++xy_out=<unit> or <conversion_factor>¶: Horizontal output units. See Distance units and Angular units +for a list of available units. <conversion_factor> is the conversion factor +from the output unit to metre for linear units, or to radian for angular +units.
+

+ +

++z_in=<unit> or <conversion_factor>¶: Vertical output units. See Distance units and Angular units +for a list of available units. <conversion_factor> is the conversion factor +from the input unit to metre for linear units, or to radian for angular +units.
+

+ +

++z_out=<unit> or <conversion_factor>¶: Vertical output units. See Distance units and Angular units +for a list of available units. <conversion_factor> is the conversion factor +from the output unit to metre for linear units, or to radian for angular +units.
+

+ +

++t_in=<unit>¶: Temporal input units. See Time units for a list of available units.
+

+ +

++t_out=<unit>¶: Temporal output units. See Time units for a list of available units.
+

+ +

+

Distance units¶

+

In the table below all distance units supported by PROJ are listed. +The same list can also be produced on the command line with proj or +cs2cs, by adding the -lu flag when calling the utility.

+ ++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

Label	Name
km	Kilometer
m	Meter
dm	Decimeter
cm	Centimeter
mm	Millimeter
kmi	International Nautical Mile
in	International Inch
ft	International Foot
yd	International Yard
mi	International Statute Mile
fath	International Fathom
ch	International Chain
link	International Link
us-in	U.S. Surveyor’s Inch
us-ft	U.S. Surveyor’s Foot
us-yd	U.S. Surveyor’s Yard
us-ch	U.S. Surveyor’s Chain
us-mi	U.S. Surveyor’s Statute Mile
ind-yd	Indian Yard
ind-ft	Indian Foot
ind-ch	Indian Chain

+

Angular units¶

+

New in version 5.2.0.

+

In the table below all angular units supported by PROJ unitconvert are listed.

+ ++++ + + + + + + + + + + + + + + + + +

Label	Name
deg	Degree
grad	Grad
rad	Radian

+

Time units¶

+

In the table below all time units supported by PROJ are listed.

+

+
+
Note
+
When converting time units from a date-only format (yyyymmdd), PROJ +assumes a time value of 00:00 midnight. When converting time units +to a date-only format, PROJ rounds to the nearest date at 00:00 +midnight. That is, any time values less than 12:00 noon will round to +00:00 on the same day. Time values greater than or equal to 12:00 noon +will round to 00:00 on the following day.
+
+

+ ++++ + + + + + + + + + + + + + + + + + + + +

Label	Name
mjd	Modified Julian date
decimalyear	Decimal year
gps_week	GPS Week
yyyymmdd	Date in yyyymmdd format

+

+ + +

+