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Direct solution Choose from menu
Return to menu [CR][Q] <== Return to last menu
The direct solution is started by defining a current station [C] and fore station [F]. If the station [C] does not have coordinates the user will be prompted for a latitude and longitude.
The user can define a back station [B] and enter a direction/angle or enter an azimuth and distance to the fore station. If the back station has no coordinate value the user will be prompted for a latitude and longitude.
The user can now enter a series of either direction [1] and distance [2] or azimuth [3] and distance to the Fore station. When the program has sufficient information it will compute the coordinates for the fore station. If the fore station already has coordinates it will compare the computed value with the stored value and prompt the user for a choice of old value, new value or mean to store.
Observations as computed from inverse computations will be listed, where possible, when observations are entered.
The program will save the observations and if desired the user can perform a simple adjustment. [A] The program lists the number of observations and the number of free stations as the data is entered.
The user can choose to continue the direct computation either from the same station or by changing the Current station number [C] The user can use the traverse mode [N] where the Fore station becomes the Current station and the current station becomes the Back station.
For the direct solution there are 3 stations defined
The back station is required when using a direction/angle to define the azimuth from the Current station to the fore station. The back station must have accurate coordinate values as the program uses the value to compute the azimuth between the Current and fore stations.
If the program detects an existing name in the coordinate list that matches the input name it will use the existing coordinates otherwise it will prompt for accurate coordinates.
For the direct solution there are 3 stations defined
The current station is where the azimuth and distance originate. The direct computation uses the cordinates from this station along with the azimuth and distance to to fore station to compute coordinates for the fore station
The user starts by entering a unique station name. If the program detects an existing name in the coordinate list that matches the input name it will use the existing coordinates otherwise it will prompt for accurate coordinates.
For the direct solution there are 3 stations defined
The fore station is the one to which the direct solution is required. The program uses the input/computed values of azimuth and distance to compute fore station coordinates.
The user starts by entering a unique station name. If the program detects an existing name in the coordinate list that matches the input name it will use the existing coordinates otherwise it will prompt for accurate coordinates.
A set of directions is the recorded measurement of an angle or angles. Each direction can be considered a ray originating from the measuring instrument to a target. The first ray is normally assigned the value of 0 degrees, 0 minutes and 0.0 seconds. Each subsequest direction is recorded as the angle measured clockwise from the original ray to another ray. (if the original ray is non zero then the subsequent direction value will be the angle between the rays plus the value of the original direction.)
In this case only the difference between the two directions or angle is required.
The program will prompt with an approximate angle value as computed from the coordinate vales in memory.
The angle is entered as DD.MMSSSS where DD is the degrees, MM the minutes and SSSS the seconds.
The distance is the measurement in meters between the vertical projection of the current station on the ellpsoid to the Fore station vertical projection on the Ellipsoid along the geodesic line . Sometimes known as the sea level distance.
The program will prompt with a distance as computed using the cordinate values of the current station and the fore station.
The distance is entered in meters properly reduced to sea level.
The azimuth is the angle from north measured clockwise towards a target. Azimuths are referred to
The azimuth required here is the Geodetic azimuth (ellipsoid)
The astronomic azimuth can be reduced to the Geodetic azimuth with a correction for the deflection of the plumbline.
Magnetic north can be reduced to Geodetic north through use of magnetic declination tables.
This option can be used to compute a traverse which is a series of connected rays. Having computed a fore station it will now become the current station and the previous current station is now the back station.
If the new station has an existing coordinate the new value will be compared to the existing one.
This option allows you do adjust your observations as soon as you have sufficient values. Normally you would wait until you have a loop closure.
As you enter observation values they are saved in an array. Stations that exist already are fixed and new stations are adjusted. The observations are parametrized and the resultant normal equations solved in a least squares process.
The new stations are saved in the coordinate array and can be used in subsequent operations.