Crad

Command line: Crad

Description: calculate sightshot points (polar points) coordinates

TopoLT toolbar:

Menu: TopoLT » Coordinates » Calculate polar points

With this command you can calculate points coordinates by two methods: polar and direct intersections.

Function can also be called from CAD and directly from Windows too. In case it is called from CAD, if there is a file with the same name as dwg drawing but with extension .rad then this file with measurements in TopoLT format is automatically opened. At calling from CAD, button of points drawing is active.

Window is organized in 3 zones as following: station points coordinates table (known coordinates points), measurements panel and coordinates table of calculated sightshot points. User can dimension the 3 zones, messages box and table columns.

Description of table with station points coordinates:

Using button [Add files] you can add coordinates from a text file with mention that at station points taking over you can make a filtration by code accordingly to settings described at Options sightshot points calculation.

Using button [Save stations] you can save in a file only the points from table to use them by example in another project. To avoid this file name to be identical with the file where simple points are saved attach to the name in parenthesis the station code introduced at Options sightshot points calculation.

To empty stations table use button [Delete all] or select all with Ctrl+A “Select all” and delete with Ctrl+X “Cut”.

Description of measurements panel:

Measurements panel contains: stations points list, selected station point, instrument height, backsight points used to calculate station’s orientation, table with measurements of sightshot points and messages text box.

To introduce a new station push button [+] and a station with name NewStn will be introduced after which you can change it or by choosing the station from list (the list contains all names found in station points table) or by typing.

To delete station or selected stations press Del or push button [-] and to move a station into the list use button [v] or [^].

In the table with backsight points used to calculate station’s orientation introduce horizontal and vertical angles. Vertical angle is used only to identify in which position of telescope, I or II, horizontal angle was measured.

When the calculation of station’s medium orientation is possible (Omed) calculated value is shown.

The columns of measurements table are: point name (number), slope distance (D), horizontal angle (Hz), zenithal angle (V), target height (H.refl) and code that describes point.

The number of polar point can be incremented or not with a value accordingly to settings described at Options sightshot points calculation. If point doesn't have a name (number) it will be omitted at calculation.

If measured distances to sightshot points are introduced then the point will be calculated as polar point. If distance is not introduced or if it is 0.0 then point will be calculated through direct intersection with mention that it has to be at least one point with the same number vised from another station to make the direct intersection calculation possible.

Points can be renumbered using button [Renumber points]. Double, triple points and so on are considered at renumbering. There can be points with the same number when they are measured many times or when they are determined by direct intersection. At renumbering, sightshot points that are used as station or as points vised for orientation, are not changed.

Using button [Import measurements] can be imported measurements from instruments (total stations). Examples with accepted formats you can find using path “C:\Program Files\TopoLT\Example\PolarPoints\”.

Imported data can be also unreduced measurements (D, Hz, V) and reduced measurements as (Do, Hz, dH) or (Do, Hz, V). Reduced measurements are changed in (D, Hz, V). In this case you have to consider the corrections made by instrument in the moment of measurements so that you don’t have to correct them once again when you make calculation. In the case of reduced measurements corrections that can be made twice are: correction to eliminate the influence of earth curvature and atmospheric refraction or to reduce horizontal distances to projection plan. Because of that it is recommended the using of unreduced measurements (D, Hz, V).

In case of instruments with data formats that have not defined stations or backsight points (for stations orientation) there are used codes to identify them. These codes can be set using button [Options]. The description can be found at Options sightshot points calculation. To see how these identification codes are introduced or in what position is a point code accepted read files with examples (Format-Zeiss.dat, Format-Sokkia.sdr, etc.).

To implement another format files then these supported by this program version you can send an e-mail with an example of your file. Message must contain: manufacturer's name (Ex. ZEISS), instrument type (Ex. RecElta 13CM), file format if you know it (Ex. Rec500), extension used for this type of file (Ex. .rec) and file. In the shortest possible time we will try to implement this format.

Using button [Save measurements] you can save measurements data with TopoLT format in a text file. There are saved the following data: settings with parameters used accordingly to calculation option, station points and sightshot points measurements.

Description of table with calculated coordinates of sightshot points:

In this table will be written calculated coordinates of sightshot points or, in case of some errors where tolerance is exceeded, only calculated coordinates for points that do not take part in tolerance (for checking).

This table is not editable. It can just be copied by typing Ctrl+C or choosing “Copy” from pop-up menu.

When you calculate, you can introduce at the beginning of the table, station points coordinates. This option, to introduce or not station points, can be changed accordingly to settings described at Options sightshot points calculation.

You can empty table using button [Delete all] or you can save it in a text file using button [Save points]. The format in which you may save these points can be a simple coordinates text file .coo or a .csv file. Points can also be saved in a format for coordinates defined by user (see section Instrument).

In case this function is called from CAD program button [Draw points] is active. If this button is used then coordinates from this table will be sent to the function of drawing points RapPct.

General considerations:

Data can be introduced in table also by copying them from another table (Excel, Word, etc.) or from a text file that uses characters <Tab>, <Space>, <;> or <,>, with Ctrl+C to "Copy" and Ctrl+V to "Paste". When you copy in a table, be careful not to be positioned inside a cell, because in this case copying will be made only in that cell.

Angles are accepted only in centesimal degrees. Horizontal angle must be measured clockwise (positive sense) and vertical angle must be measured from zenith (zenithal angle). Coordinates and distances can be in meters or in inches depending on the settings made at section UnitsTopoCfgUnits. The decimals number for distances, N, E, Z coordinates can changed using command TopoCfg section Units.

When mouse pointers rolls over column 1 from each table a message appears that informs you about the row number and, for columns where points codes are written, it will appear translated code of the point accordingly to codes interpretation file described at section Files.

To delete fast all stations, enter the stations list, type Ctrl+A to select them all then press Del or button [-].

If you want to search a station fast, double click on desired station from stations list, or on selected station or in orientation vises. If station exists in station points table then the row will be selected.

If you want to search for a point type Ctrl+F and choose “Find point” from pop-up menu. The next search can be done pressing F3 or from menu with “Find next”. Search is made only for the zone in which you are respectively: station points table, all measurements or calculated points table.

When in message box are error or warning messages, you can identify quickly what station or point provided message, by double clicking on selected message or by pressing Enter.

Calculation mode:

Step 1. There are calculated possible medium orientations for stations. In case medium orientation exceeds orientation tolerance this error is notified.

Step 2. There are calculated sightshot points that can be stations or points vised for orientation (case of polar stations or determination of a point that will be used only for other stations orientation).

Step 3. There are calculated medium orientations for stations that were not calculated at step 1. It is also checked for these stations if orientation tolerance was exceeded.

Step 4. There are calculated sightshot points that were determined through direct intersection. If intersection is multiple then the media is calculated. The medium value must not exceed tolerance on N, E and Z. Otherwise, errors will be notified.

Step 5. There are calculated sightshot points that were determined as polar points. If points are determined several times then media is calculated. For points to which media was calculated it is tested if tolerance on N, E or Z was exceeded.

You can find description about reductions that were used at calculation at Options sightshot points calculation.

Explanations about warning messages:

Warning messages must not be ignored, they are inspired from practice and if you consider them you can avoid some incorrect calculations. With a double-click or pressing Enter you can reach at the station or measurement that provided message.

Warning message «Station ... has the same height as previous station» is notified because in practice it is a rare case. In this case you must check if you didn’t forget to record the height of the station mentioned in message. If indeed, by chance, the two stations have the same height then message can be ignored.

Warning message «Possible unchanging of target height for station ...» is notified when, for example, measurements in a station were begun with target putted on height 1.5 m and were finished with target putted on height 2.0. m. Usually, in the next station measurements begin with target putted on initial height of 1.5 m. If this value of 1.5 m was omitted to be recorded at the beginning of the second station then the warning message is notified. If you realize that in the second station the target was really putted on height 2.0 m then you can ignore this message.