Point storage and classification
How you record a point determines how it is stored in the Trimble Access software. Points are stored either as vectors or as positions. For example, RTK points and conventionally observed points are stored as vectors, while keyed‑in points, real‑time differential points, and postprocessed points are stored as positions.
To review details about a stored point, tap and select Job data / Review job. A point record contains information about the point, such as the point name, the code, the method, the coordinates, and the GNSS data file name. The Method field describes how the point was created.
The coordinates are expressed as Global, local, or grid coordinates, depending on the setting in the Coordinate view field.
To change the coordinate view settings, do one of the following:
- From the Job data menu, tap Review job. Open the point record and then tap Options.
- From the Key in menu, tap Points and then tap Options.
Define a datum transformation and/or a projection if you want to display local or grid coordinates for a GNSS point. Alternatively, calibrate the job.
Each point record uses the antenna height given in the previous antenna height record. From this, the software generates a ground height (elevation) for the point.
The following table shows how the point is stored in the As Stored field.
Value | What the point is stored as |
---|---|
Grid | Grid coordinates |
Local | Local geodetic coordinates |
Global | View as L, L, H coordinates in the Global reference datum at the Global reference epoch. |
ECEF (Global) | View as Earth‑Centered, Earth‑Fixed X, Y, Z coordinates in the Global reference datum at the Global reference epoch. |
ECEF deltas | View as an Earth‑Centered, Earth‑Fixed X, Y, Z vector in the Global reference datum at the Global reference epoch. |
Polar | Azimuth, horizontal distance, and vertical distance. This is a vector. |
HA VA SD | A horizontal circle reading, vertical circle reading (a zenith angle), and slope distance. This is a vector. |
HA VA SD (raw) | A horizontal circle reading, vertical circle reading (a zenith angle), and slope distance with no corrections applied. This is a vector. |
Mag.Az VA SD | A magnetic azimuth, vertical (zenith) angle, and slope distance vector. |
MHA MVA MSD | A meaned horizontal angle from the backsight, meaned vertical angle (a zenith angle), and meaned slope distance. This is a vector. |
USNG/MGRS | USNG/MGRS string and elevation |
Read the As Stored field in conjunction with the Method field.
The Global reference datum and the Global reference epoch are shown in the Select coordinate system screen of the job properties. See Coordinate system.
For points calculated using Cogo/Compute point, you can choose how to store that point. The available options depend on the selected coordinate system and the type of observation used in computing the point.
Points stored as vectors are updated if the calibration or coordinate system of the job changes, or the antenna height of one of the source points is changed. Points stored as Global coordinates (for example, an offset point calculated using the From a baseline method) are not updated.
For GNSS points, Quality Control (QC) records are stored at the end of the point record.
When points are stored they have either one or two classifications:
- Points that have been measured using GNSS have an observation class and a search class.
- Points that have been keyed in, computed, or measured with a conventional instrument or laser rangefinder have only a search class.
The following table lists the GNSS observation classes and resulting solutions.
Observation class | Result |
---|---|
RTK | A real‑time kinematic solution. |
L1 Fixed | An L1 fixed real‑time kinematic solution. |
L1 Float | An L1 float real‑time kinematic solution. |
L1 Code | An L1 code real‑time differential solution. |
Autonomous | A postprocessed solution. |
RTKxFill | A real‑time kinematic solution using xFill. |
SBAS | A position that has been differentially corrected using SBAS signals. |
Network RTK | A real‑time kinematic solution using Network RTK. |
RTX | A position that has been generated by the Trimble Centerpoint RTX correction service. |
WA Fixed | A fixed solution using wide‑area processing. |
WA Float | A float solution using wide‑area processing. |
OmniSTAR HP | A high‑precision OmniSTAR corrected solution (HP/XP/G2) |
OmniSTAR VBS | An OmniSTAR VBS differentially corrected position |
For postprocessed surveys, the observation class is autonomous and no precisions are recorded.
A search class is applied to a point when it is measured, keyed in, or computed. The search class is used by the software when details of a point are required for stakeout or calculations (for example, for Cogo calculations).See Database search rules.