Convert time stamps
Convert time stamps command can be used to convert the format of time stamps. Supported conversions are:
INPUT FORMAT |
CONVERTED FORMAT |
|---|---|
GPS seconds-of-week |
GPS standard time |
GPS time |
|
GPS standard time |
GPS seconds-of-week |
GPS time |
|
GPS time |
GPS seconds-of-week |
GPS standard time |
|
GPS seconds-of-day |
GPS seconds-of-week |
GPS standard time |
|
GPS time |
|
Unix time |
GPS seconds-of-week |
GPS standard time |
|
GPS time |
|
UTC seconds-of-day |
GPS seconds-of-week |
GPS standard time |
|
GPS time |
|
UTC seconds-of-week |
GPS seconds-of-week |
GPS standard time |
|
GPS time |
The conversion is necessary, for example, if data collected in several weeks is processed together in one project. Then, GPS seconds-of-week time stamps result in repeated values and GPS standard time must be used in order to provide unique time stamps for each trajectory position. This is a requirement for many processes that rely on trajectory information. Some post-processing software generates data with Unix or UTC seconds-of-day time stamps. They must be converted into another GPS time format as well.
It is essential that time stamps of trajectories and point cloud data are stored in the same GPS time format.
To convert time stamps:
1. (Optional) Select trajectory file(s) for which to manipulate time stamps.
2. Select Convert time stamps command from the Tools pulldown menu.
This opens the Convert Trajectory Time dialog:
3. Define settings and click OK.
This converts the trajectory time stamps to the new format. The modification is saved to the trajectory binary files in the active trajectory directory. An information dialog shows the number of effected trajectories.
SETTING |
EFFECT |
|---|---|
Apply to |
Trajectories for which the conversion of time stamps is applied: •All trajectories - all trajectories in the list. •Selected only - selected trajectories only. |
Method |
Defines the computation method of modifying time stamps: •Source and target system - conversion from one time format to another. •Multiply and add constant - constant value by which time stamps are multiplied or that is added to current time stamps. |
Current values |
Original time stamp format of the trajectory positions. This is only active if Method is set to Source and target system. |
Convert to |
Target time stamp format. This is only active if Method is set to Source and target system. |
Survey date |
Date when the trajectory data was captured. The format is day/month/year (dd/mm/yyyy). This is only active for the conversion from GPS seconds-of-week or UTC seconds-of-day/week to GPS standard time or GPS time. |
Multiply by |
Factor by which current time stamps are multiplied. This is only active if Method is set to Multiply and add constant. |
Add |
Value to add to GPS time stamps when converted from UTC seconds-of-day time stamps. Refers to the leap-seconds that by which GPS time is ahead of UTC time. This is only active for the conversion from UTC seconds-of-day/week to any GPS time format. Value to add to current time stamps if Method is set to Multiply and add constant. |
