Instrument Guidance and Data Acquisition in Topographic Surveying
Guidance from the station
The procedure to locate the origin of the equipment at O so that the 0G occupy a certain position, called the instrument guide and refer to them as we work with the instrument orientado.En this case has been placed as reading of the value of the azimuth reference to it from the point source. Observation of azimuthal directions can be performed from an arbitrary origin of the position of the 0g value of the equipment, or it may be an early indication of it to a reference source.
Is realized or not the orientation of the team, this will not make any difference in outcomes. Use one method or another depends on the preferences of the operator or complementary needs of the project which is underway, such as conducting simultaneous rethinking, or checks of any kind that you want to perform from the same parking lot.
Data field
The field data acquired in the method of radiation are: · Views azimuthal to the reference points and radiated. · Views zenith. Distances. · Height of instrument. · Height of the signal, which has done the shooting.
Brief description of item · radiated.
Croquización and nomenclature of the points
As is done with data acquisition equipment is necessary topographical sketches that reflected the relative position of all points. Radiated points are numbered in a corresponding manner, taking special care that the numbering is recorded in the sketch matches the scoring going in the summary or logging onto the electronic book.
SKETCH
Make a preliminary recognition of the area under study to get an idea of the contents of our sketch. It should include as much information as possible to let us seize the entire surface of paper that we have, for which “Do not include brackets: they occupy much space. With annotations and abbreviations we obtain the same objective. Do not use the back of the paper: A sketch is a sketch quick reference. Make brief sketch, concise but understandable by anyone, since in many cases, they will use someone who was not on the scene object of the uprising. The lines must be clean and clear, making clear where they begin and where they end. No overlap strokes. Need not be made with a ruler. To review the proportionality of the drawing as a whole. Include, if appropriate, information altimetry. Include, wherever possible, names of adjacent streets. Always indicate the date of execution of the sketch, and the author. If you have additional information or photographic mapping, include as many reviews and annotations as necessary as an attachment to the sketch. A sketch is a floor plan. C ONTROL FOR REFERENCES.
Before making topographical data with a computer will have done the check or verification thereof. As we have indicated it will begin acquiring information by observing one or more references, which will allow us to obtain the value of thedisorientation angle, thereby calculating azimuths. Throughout the data collection is needed again aiming successive controls one or more references to verify that the team has not suffered any displacement, and therefore to ensure that the angular origin has not changed. In the event that the new reading to the / s disagrees with the initial reference to a value greater tolerance, be annulled all data recorded from control to the previous reference.
Orientation / Disorientation in calculating azimuths:
With oriented instrument.
If the instrument was oriented to a reference in the field, we obtain readings that would be directly radiated azimuths to points.
With instrument disoriented
If the instrument has not been targeted previously in the field, azimuthal readings have an arbitrary origin. We as previous data the azimuth or direction of one of the addresses stamped, and with this parameter will be possible to deduce the azimuths or directions of the remaining operating directions as follows: The pa perform the lift team will consist of: total station, tripod wood , jalon, prism or miniprism, cane, and other accesorios.Es flexometer advisable to perform a recognition among the field in order to determine the areas to lift from every station so as to determine where radiation may be necessary without reflector for reasons of inaccessibility ( walls, cliffs and overhangs). The field data will be: Reads azimuthal references and points radiated readings zenith, distance, height of instrument, signal height, brief description of radiado.Dado point that the data capture can take some time, with the consequent risk that the device against a foreign movement, it should endorse a reference well-defined periodically, as well as at the beginning and end of each data collection estacionamiento.La is complemented by the sketches that correctly identify each point and that will be of great help in cartographic publishing. The points raised are correctly and fully define the area: valleys, dividing lines d rupture, filling points and detail pts planimetricos.Todas observations radiated points are stored in internal memory of the station and can be transferred to your computer ASCII format directly, or through a checking element auxiliar.Tras files is the calculation of the misdirection of toas stations from which it was radiated, using the observations at time points with coordinates calculated the disorientations conocidas.Una , using a calculation program is calculating the radioacion. Files are selected comments and files points which are the coordinates of all the bases with associated disorientation and performs the calculation of the coordinates of all observed points. You get a file with the number and coordinates of every last punto.Por this file is exported to a DXF format for further processing by any CAD program. The program draws MicroStation or Autocad, one can observe the state of the point cloud and detect possible errors such as poorly defined areas of the ground.
THE LIFT WITH GPS.
If the terrain permits can choose to work with GPS methodology, with fast-static observations in real time (RTK)
. Q It is important to the work of real-time GPS are a form of positioning, but a way to calculate q-base lines originate in differential positioning. The principle of the method is to establish a fixed reference station, static and other station and another mobile station, at points on the field you want to take data. To work with this method is necessary initialization of the team, q is the Calulo of all the baseline parameters q joins the movl and the reference in an instant. Once that is done, will retain the values of the ambiguities, which makes q the number of unknowns is reduced to three (X, Y, Z) and which require less information age pa solve the system and therefore less laying period of observation. The team fixed its coordinates will be introduced in ED50. This device sends signals to the mobile equipment and proceeds to perform the lift. Stationary equipment is parked on one of the vertices of the basic network vertex q is considered as reference and will be in charge of transmitting the position to field teams in charge of the uprising.
The real-time work is limited by the radio link. The radio modems do not reach more than 8km.Este problem is solved using q mvi ensure telephony long distance links. The phases of work are: reference station at a point of known coordinates, entering its coordinates and commissioning, equipment assembly and initialization movl it. Gathering data points by assigning codes to recognize when the computer to be flushed through the terminal and seasonal changes where necessary.