Right path. Types of analytical (written) number. Purpose and types of Note. Main goals
Accounting for the movement of the vessel in order to determine its current coordinates or application of the map is called notepathvessel.
Through simple calculations or graphic constructions, the number should be displayed at any time to display the place of the vessel relative to the environment with an accuracy of navigation security, i.e. It must be continuous, visual and accurate.
There are two types of numeration: graphic, in which it is performed in the form of graphic constructions on marine navigation maps, and analytical, or written, in which the coordinates of the vessel are calculated by formulas.
Both types of number can be performed automatically and manually. In navigation, the greatest distribution received a graphical number as responding to all presented requirements and especially in terms of visibility.
Automatic graphical viewing is carried out using special devices - automotes.
Manual graphical number is performed by the vessel's navigator using a gasket tool. At the same time, it is necessary to solve the direct and inverse task.
Straighta taskit comes down to accounting by the movement of the vessel, when the steering rate is given and know the testimony of lag in the original and given points at the time of calculation.
In this case, formulas (26) are solved (34) to calculate IR.
If there is no drift from the wind and demolition of the flow, then by paving the line of the true course from the original point, we will have on the map the direction of the actual movement of the vessel. This is true if the correction of the exchangeer is known to be unmistakably, and the digging of the steering is slightly and symmetrically relative to the specified QC.
The course line on the map is carried out by a simple print pencil "TM", thickness equal to the thickness of the meridians and parallels. It indicates the value of the compass course and the compass correction (Fig. 32).
From the initial point in the direction of the true course, the found distance is laid down. The point is called in this way with the help of the point is called a bit and designated on the map in the form of perpendicular and symmetrical to the lines of movement of the tower of a length of 5 mm. The point is signed in the form of a fraction: in the numerator shipping time - hours and minutes, in the denominator - the corresponding value of the lag counting up to 0.1. Damn the fraraty is carried out on the line horizontally.
If the diving area acts the flow and wind, then appropriate calculations and construction for their accounting are performed.
Often the vessel has to decide inversetask.It occurs every time when the direction of the forthcoming movement of the vessel is scheduled on the map or calculations of arrival at a specified point are performed.
In this case, from the source point on the map, the line of the forthcoming navigation of the vessel is scheduled and its direction is removed. In the absence of drift from wind and flow, the resulting direction is a true course of the vessel. Based on this, the compublic rate for the steering according to formulas (27) and (35) is calculated.
where t 1, ol 2 - time and countdown of lag at the starting point;
T 2, OL 2 - time and counting of lag arrival at a specified point.
Let us consider what the accuracy of the considered place is subject to the absence of external factors (wind and flow).
Suppose that the vessel needs to go through the same course from the point BUTin the distance removed from it IN(Fig. 33).
Due to the fact that the correction of the compass is known to the vessel with some kind of error ± m 0 Δk , then ship passing distance S,depending on the error, it may be either at the point IN",either at point IN" .
Thus, the ship's location error from an error in a compass correction will be depicted by arc BB "= BB ",the value of which is easily determined from the expression
or for approximate calculations
The error in accounting by the vessel of the distance ΔS due to an error in the amendment of lag ± t Δl, pronounced in percent, or the coefficient of Lag ± M CL, expressed in fractions TO L., can be determined by formulas
Fig. 33. Square of probable place is pic. 34. Elliptic error
location vessel vessel
With a positive meaning Δs.the vessel taking into account the error in his course will be on the arc D "D",with a negative - on the arc With "C".
From here it can be concluded that, with simultaneous action of errors in the testimony of the compass and lag, the vessel will be within the so-called Figures error C "D" D "C".
Replacing the resulting figure of error circle with a radius M. from, receive
(61)
Circle radius M. from call called around error,and radius M. from - circular (radial)errornote.
Due to the unequal influence on the accuracy of the number of errors in the course of the vessel and in the distance, the probable location of the vessel is better characterized by an ellipse with semi-axes (Fig. 34):
The value of errors in the instrument amendments to the fifty is unknown, as they are random. For calculations, their values \u200b\u200bare made based on the experience of practical voyage.
Analysis of formula (61) shows that the error of the knowledge of the vessel's place increases in proportion to the distance traveled. For this reason, it becomes possible to eliminate the accumulated error of the number with observations (observated places), i.e. Definitions of vessel vessel visual, radiotechnical and astronomical ways. The discrepancy between the sensible and observated place is called the same moment. The unpretentious is expressed by the direction of the quality point in the observated and the distance between them in miles. It is written in the following form: C \u003d 305 ° - 2.8 miles. Sneceing sign on the map is a wavy line connecting both points (see Fig. 32). The graphic image on the sea route passed by the vessel passed automatically or manually based on measurements and calculations is called the navigation gasket.
The navigation laying of the route of the vessel, performed pre-based on the scheduled route of the vessel, which meets the requirements of safe swimming, tasks and economic feasibility, is called a preliminary gasket.
The navigation laying is carried out with the yield of the vessel continuously before its arrival in the port or anchor setting. For the starting point of starting the gasket, the passage of the port of the port, the bonphic gates, the input buoy or the supervised vessel place is taken.
At the transition, the task of the vesseller comes down to ensure that the actual movement of the vessel as close as possible coincides with the route scheduled earlier. This will give the opportunity to use the calculations performed during the preliminary gasket and, therefore, will facilitate the work of the fifty in the sea.
Before entering the vessel to the flight, under the guidance of the captain on maps and navigation manuals, we study the flood conditions on the entire upcoming transition. Based on this data, perform preliminary gasket. However, it gives only a general idea of \u200b\u200bthe transition conditions. From the moment the final choice of courses and all the factors taken to account are determined by the specific navigation situation. Therefore, the flight is carried out executive gasket. It includes a path numbering, calculations and construction on the map, maneuvering calculations for discrepancies with other vessels.
Note There is a continuous record of the vessel motion elements (velocity and directions) and the effects of external forces in order to determine the coordinates of the vessel (literary place) without observations of coastal and heavenly luminaries (observations). This account is carried out on the basis of the rate values, velocity and veneer vector. The initial point for viewing on the map determines the captain. For such a point, the exact place of the vessel can be taken, obtained immediately after the exit of the port of the port, the floating lighthouse, the receiving buoy, etc. Its coordinates are recorded in the ship magazine. By the time the executive laying began, it is necessary to include lag, determine the correction of the compass in the stems or in another way.
Purchase when swimming without drift and flow. When swimming without drift and flow, the line of the vessel path on the map coincides with the line of IR, so accounting for the movement of the vessel on the map is made through the IR lines, according to which the distances passed by the vessel on a lagua taking into account its coefficient CL. From the source point on the map lay the first course line. Shot from the card IR is translated into the CC, which is on the magnetic compass. On the map above the line IR inscribed the course on the compass and its amendment. Course Distance SLdetermine by a lag:
SL \u003d CL (OL2 - OL1) ; (Where oL2. ol1 CL - Lag coefficient).
On the IR line in the following cases, the vests of the vessel are applied, i.e. the place calculated at the rate and swimming. If swimming makes close to the coast, the read points mark every hour, in the open sea - at the end of the watch. In addition, the listed place is applied at the points of the beginning and end of turns, when the speed changes, upon receipt of observations. Near the vessel's venue in the form of a fraction record a moment on shipping clock with an accuracy of 1 min (T) and a countdown of lag with an accuracy of 0.1 miles (OL). (See cris 31).
In real conditions of maritime swimming, there are three main options that determine the appropriate practical methods for measuring the yacht path:
- swimming in a sustainable complete wind;
- swimming in a stable opponent wind;
- swimming with unstable strength and wind direction.
In the first case, the yacht usually lead along the pathway, laid at a preliminary gasket. The terms of the number are favorable here. In the second case, they perform a lavaling relative to the general course, while the actual path in each gallee does not coincide with the preliminary gasket. If the lavaling is not too cool, the steering is accurately withstanding the specified course, which simplifies the number and increases its accuracy. In such conditions, the duration of the galleys depends on the alarm angle (the angle between the general course and the yacht). With the equality of the angles of the right and left galleys, their duration is the same, and the lava can be symmetrical. If there is no - the path numbering and gasket are performed on each private lavaling gallee according to the instruments. If there is no lag, speed is recommended to evaluate on each gallee.
When rail, it may happen that the steering on the instructions of the captain of the yacht, choosing to the wind, does not pay attention to the compass. Here through small, but equal intervals (15 - 30 min.) Determine and record the average QC and the corresponding IR, according to which the data obtained by lag or speed is delayed. In case of unstable wind, the steering rate is not asked, but put the task to rule on the sail in search of wind, adhering to the goal closer to the generator. Sometimes in such a situation, depending on local signs and weather forecast, it is advantageous to avoid the general course, in order to get a full steady wind (for example, a breeze under the coast). In all these cases, in the interests of the number of paths on the yacht, all turns are recorded and at each gallee (at the beginning and end of the galks must) with a certain periodicity (1-2 times per hour, depending on the conditions) record the data on the movement of the vessel (time, course , speed, counting lag). These entries are treated, averaging course and speed of each galks, and then packed on the map.
Practice shows that the accuracy of the number in such conditions increases with increasing discreteness of observations. Errors of approximation of curvilinear sections of swimming in straightforward will be insignificant compared to other errors.
Ship drift. In the navigation drift ( "A") They call the demolition of the vessel from the course line under the joint action of the wind and the excitement caused by it. With drift, the vessel moves relative to the water under the joint action of ship machines and wind. The line of its actual movement (s), called the line of the vessel path during drift, does not coincide with the course of the vessel (OA). (See cris 33). When the line is shifted to the right from Dp. Ship (the wind blows in the left side) a. Plus (+) attribute a sign plus (+), and when shifting to the left (the wind blows into the right side) - a minus sign (-). Dependence between a travel angle taking into account the drift ( PA), IK and a.:
PA \u003d IR + A; IR \u003d PA - A; a \u003d PA - IR
The drift angle can be determined by comparing the actual path of the vessel obtained by observations, with IK. When follows, the shores are carried out a number of reliable navigation observations. By connecting the observed points, receive a line of valid movement of the vessel, i.e. the line of the route during drift PA(Fig. 34). The angle between the line of the path and laid on the line map IK corresponds to the corner of the drift. The found angle of drift with his sign is taken into account with further number. If in the diving area there is a flow, the resulting degree of demolition will be the result of the impact on the ship not only wind, but also the flow.
Accounting drift by reference. If the vessel is experiencing a drift, then when conducting a gasket on the card, the ship's line of the vessel during drift is applied. On it inscribed Kk, Compass Amendment and Drive Angle Accounting a. with your sign. On the way the paths are deposited by the distance passed SL. It is believed that a.
SL \u003d CL (OL2 - OL1) ; (Where oL2. - the countdown of Lag at the point of finding the vessel, ol1 - the countdown of lag at the starting point, CL - Lag coefficient).
If the vessel is not sure about the accuracy of the drift angle, then to control the safety of swimming, except the path line during drift, it is recommended to apply a line to the card IK. Both of these lines should pass purely about underwater obstacles. The number is based only on the path line, according to which the vessel is moving.
Sea currents. Marine currents are called horizontal movements of large mass of water. The flow is characterized by its elements: direction and speed. Direction of flow Kt. Indicate in degrees in a circular account or rumbach and set at that point of the horizon, to which the current is directed. Flow rate Vt. Measure in nodes, and small speeds - in miles per day. According to the nature of the flow, it is classified for permanent, the elements of which from year to year almost do not change, periodic, whose elements are changed on a certain law, and temporary (random), the elements of which can change dramatically. In practice, the fifty most often has to deal with constant and periodic (adorid-tidy) currents. Information about the elements of constant and adorid-tidy currents is placed in closets, atlas of flows and on maps. At the same time, the average values \u200b\u200bof the elements of the flows that can differ significantly from valid are indicated. The movement of the vessel relative to the soil when swimming during the flow is determined by the following factors (Fig. 36).
Under the action of ship cars, the vessel moves relative to the water in the direction of its Dp., i.e. the lines of the true course of OA. Vessel speed relative to water is speed VL Showed by lag. At the same time together with the entire mass of water, the vessel is demolished relative to the soil in the direction of the flow of one at the rate of flow Vt.. As a result of the soil, the vessel moves according to the referring OB with a speed called the true speed of the vessel V.. Wherein Dp. The vessel remains parallel line IK. The OB line, according to which the vessel moves under the joint action of ship machines and flows, is called the line of the vessel path during the course. The position of the path of the path with respect to the true meridian is determined by the NOB angle, which is called a travel angle during PU. Angle "" , enclosed between the line of the true course of the OA vessel and the OB path line, is called a demolition angle. With the demolition of the ship to the right of it Dp. (The current is sent to the left side) attribute the sign "+", and when demolished left-sign "-". Relationship between ( PU), IK and:
PU \u003d IR +; IR \u003d PU -; \u003d PU - IR
Purchase when swimming during the flow. When swimming on a constant flow on the card, the ship route is applied by the ship route, according to which it actually moves relative to the soil. Over the path the paths inscribed Kk, Compass amendment and demolition angle with your sign. For auxiliary calculations, the thin line also causes a line IKon which the distances are laid SLpursued by a vessel regarding water according to lag testimony. Points obtained on line IK, tolerate in the direction of flow to the line line (Fig.37). Curly points on the line of the way make the time mark and the countdown of the lag, and the corresponding points on the course line are just the reference of the lag. Points of traverse, opening and hiding the landmarks are applied to the line of the way (Fig.38).
Speed \u200b\u200bwith joint accounting of drift and flow. Consider the case when the vessel moves relative to the soil under the joint action of ship vehicles, wind and flow. To conduct a numbering on the map, lay the line of the ship during drift and flow and inscribed Kk, Compass Amendment and Total Demolition Angle
c \u003d a +.
In addition, for auxiliary calculations on the map, the line of the road during the drift, on which the ship sailing is deposited SL. Each point on the line of the path during the drift corresponds to the point on the line of the valid movement of the vessel. These points are interconnected by the flow vector. Graphically, the tasks associated with finding the path of the path during drift and the flow, true speed V. and total demolition angle from According to the specified Kk, VL, a., and elements of flow, applying a particular place, the pre-deputy time and oL. At the time of coming at a given point, finding a landmark traverse, decide the same way as when swimming during the flow, but all auxiliary buildings are made on the line of the path with a drift replacing line IK.
Estimates of the accuracy of the number. As a result of the impact of unaccounted errors, the actual path of the vessel and the distance passed (swimming) will not correspond to those taken into account when reading on the map, and the actual place of the vessel is considered. For approximate judgment on errors in the number, the following data can be used, which reflect the accumulated generalized experience of journalism and studies. Duration of swimming (clock) corresponds to a radial average quadratic error of viewing, % from S.:
Up to 3h - 10%; 3-6h - 9%; 6-10h - 8%; 10-14h - 7%; 14-18h - 6%; 18-23h - 5%; 23-25 \u200b\u200bh - 4%; More than 35h - 3%.
When laying the path of the vessel on the map in a particular distance from navigation hazards, it is necessary to take into account the possibility of deviation of the vessel from the path line, and the value of the deviation will increase with an increase in the distance traveled, especially when swimming with drift and flow. Insufficient number accuracy causes additional control over the location of the vessel, i.e., determining its place not only by number, but also on observations: navigation, astronomical or using GPS.
Determining the vessel location by calculating its current (readable) coordinates from the known initial at the rate, speed taking into account drift, demolition and time is called the number of vessel coordinates ( speed \u200b\u200bof the path of the ship ) or abbreviatednote .
The coordinates of the list of vesselses clealed coordinatesand indicate:
φ FROM - ligorous latitude;
λ FROM - Cleaver longitude.
Clear place - The vessel place defined on the basis of the number of coordinates of its place.
Number assignment it is the orientation of the vessel on the area with an accuracy that provides navigation safety of its swimming.
The line according to which the vessel is actually moving under the action of movers, wind and flow, called path line.
Number essence It is that the directions of the vessel movement are laid on the navigation map on the navigation map and the distance passed on them in order to obtain its place at any given point in time.
Number ship coordinates classified:
According to the method of number :
graphic based on the continuous accounting of the number elements and the image of them on the navigation map;
analytical based on the calculation of current coordinates for certain mathematical dependencies.
According to the degree of automation :
automatic produced by special computing machines (autocalate, car trafficking, etc.);
observation , automatic view based on the continuous refinement of the currently read coordinates on external benchmarks;
manual produced using graph-analytical actions performed manually or using tables.
Requirements for the cost of the ship
For hoursthe following is imposed requirements:
note must be conducted continuousTo know the vessel's place at any time (its current coordinates) regarding the locality;
number must be accurateto ensure the navigation saving of swimming and the solution of the tasks inherent in this vessel;
note should be enough simple and visual.
The preferred method of accounting for the movement of the vessel is automatic with mandatory manual graphicsthat, essentially, satisfies all the requirements for a surrender.
Even with the presence of modern navigation systems in which the number process is fully automated and has a high accuracy, manual graphical numbers are mandatory to control and exclude misses in the event of malfunctions in devices.
Handmade graphic viewing method is often called navigation gasket, although the last → The concept is wider (+ definition of places, etc.).
Ship path navigation - Graphic buildings on the maritime card when solving navigation tasks of shipping.
Tasks solved with manual graphic number of the ship
In the absence of wind and the flow, the vessel moves relative to the seabed only under the action of own propellers.
If you neglected by the yaw of the vessel (the deviations of the steering from the course given to it) and consider the counterpart constant to him, then the lines of the vessel path on the navigation map is a straight line coinciding with the direction of the true course.
Ship path - The direction of moving the center of mass of the vessel, measured by a horizontal angle between the northern part of the true meridian and the line of the vessel path clockwise from 0 ° to 360 ° (circular accounting system).
Line path of the ship - The line in which the center of the vessel mass is moving relative to the bottom of the sea(Fig. 5.3).
Fig. 5.3. Line of the road and the path of the vessel
When manually reading the coordinates of the vessel without taking into account the drift and flow, the following tasks are solved:
calculation and laying of true courses;
calculation and laying of distance traversed by vessel;
accounting for circulation - changes in the course of the vessel.
Due to the number of instruments, devices are used:
repeater codecode(magnetic compass, gyrompass, etc.) - Kk;
repeater lag.(values V. L. and OL.);
tachomera(N. rpm - the number of speeds of movements);
ship clocks (current time).
For the initial point of interest, the vessel is accepted by an anchor (barrel, at the pier), determined by the observations of coastal orientations or on the number (Fig. 5.4).
Fig. 5.4. Registration of graphical number of the ship's path on the way card
1. According to the quality coordinates ( φ FROM , λ FROM) Apply the place of anchor parking, near which in a free place write the time of shooting from the anchor and the full testimony of the lag counter ( OL. 0 ):
In all cases, the fractional feature of the recording is carried out on the line and parallel parallel.
2. From the point of anchor parking, we carry out the direction of the line of the true course, calculated by the formula:
If the settlement comes from the gyrocompass, then
If the settlement comes from a magnetic compass, then
|
IR \u003d QK MK + Δ MK |
|
Δ MK \u003d D + Δ |
- Amendment of a magnetic compass.
Above the anchor parking the line of the True course (line of the way)the inscription is made:
Kk- abbreviated designation of the Compass course ( GKK, kk GL , QK P);
127.0 ° - the value of the compass rate specified by the steering (the sign of equality between Kkand 127.0 ° according to the rules is not placed);
(+ 2.0 °) - the value and sign of the accepted correction of the exchangeable indicator is indicated in brackets.
The inscription over the course line allows you to control :
Correctness of the deduction course (127.0 °) steering;
The magnitude of the accepted and accounted for amendment of the exchangeer (+ 2.0 °);
The correctness of the direction of the True Course line on the map (129.0 °).
When following the vessel at the specified course, the steering regularly (every 15 minutes) checks the readings of courses on the main exchange rate ( GK.or by H.or other) and in a magnetic compass with a report to the Watchthe Captain (Watchthe Assistant Captain).
The listed coordinates of the vessel are recorded in the ship magazine :
when shooting a vessel with anchor (barrels) and at anchor (barrel);
when swimming on the number, in the clock of multiples 4-M (00, 04, 08 ... 20);
every hour when swimming the vessel on the number near the shore;
when changing the navigator (running) watch and in other cases to indicate the captain.
On the navigation map, the vessel is applied :
in hours, multiple four (00, 04 ... 20);
when changing the vessel of its course or speed;
when changing the navigator (running) watch;
every hour when swimming the vessel near the shore or in the constrained waters, etc. Cases to indicate the captain.
To find a literary place to a given (current) time follows (Fig. 5.4):
Fix the testimony of ship clock up to ± 1 minute (11.00) ;
Fix the countdown of lag ( OL. 1 ) with an accuracy of 0.1 miles (60,4) ;
(for V. L. \u003d 18 UZ. → TO L. = 1,02)S. L. \u003d 1.02 · 11.8 \u003d 12,0 miles.
S. ABOUT =12,0 miles
provided that S. L. \u003d S. ABOUT → Postponing its value (on the scale of the card) from the original point along the line of the true course and apply the vessel's list (at 11.00) a conditional sign ( barry line IR ~ 5 mm).
Next to a particular place to record a fraction 
When reading often, it is necessary know the time and countdown of the vessel arrival at a specified point(Meeting point, anchor parking point, etc.).
Such a point can be specified (Fig.5.5):
Fig. 5.5. Methods of task on a point map
coordinates ( φ, λ );
direction on the landmark ( IPor Ku);
distance ( D.) before the guideline, etc.
Procedure for solving the problem .
Ship path graphic
Essence of graphic number
Saving safety in navigation relationship is ensured by the right choice of the route between the items and the following path.
The choice of the path is one of the most important tasks in the shipment.whose solution is based on a thorough analysis of the entire situation during the transition.
The selected ship path is applied to the card - a preliminary gasket is performed. The preliminary gasket is performed before the ship's yield in the flight of the captain. She is she is the result of work on the choice of the safe and most important way of the ship. To ensure navigation sailing safety on the map, the locations of the courses are planned, for which these points are chosen so that the points of the vessel coming to these points could be quickly defined, for example, the moments of the arrival on the traverse, on the target, etc.
We are planned in what distance capes, lighthouses, other landmarks will be held.
The declination leads to the year of swimming and inscribed its pencil magnitude to the entire ship's path ..
Over the lines of the path inscribive the values \u200b\u200bof true courses.
From the card remove the distance in miles for each course and calculate the number of miles of the entire transition.
On the road line, the boundaries of the visibility of beacons and lights for the height of the bridge are noted, outlined the most appropriate ways to determine the place of the vessel in separate areas. Time accounting is conducted with operational, counting the time of the vessel's waste at 00 hours 00 minutes.
Before performing the preliminary gasket, the map is made (see § 45).
Calculations made in the preliminary gasket process are approximate and must be adjusted during a swim.
The preliminary gasket is executed, as a rule, on travel maps.
The second most important task - Ensuring the movement of the vessel on the chosen path, for this leads continuously by the traffic of the movement of the vessel - the number of the vessel's path.
The main elements of the number are the course (according to the compass) and the distance traveled (by a lag).
Graphic number of the vessel is expressed in conducting executive navigation gasket. Its beginning coincides with the departure of the vessel from the berth (shooting from the anchor), when leaving the port, the navigator focuses on eye orientation in the surrounding environment based on the knowledge of the harbor or raid and the proper use of the TCC, SNO and natural landmarks.
With clean water, the vessel place is precisely determined and the gasket is carried out from the resulting point.
Before arrival, this point includes lags, near the source point are recorded in the form of a fraction in the numerator time, in the denominator, the countdown of lag.
From the source point, the IR line is laid on which each hour or after four hours, the readable points are noted, i.e. Places obtained without measuring navigation parameters of external benchmarks.
The read points are marked on the line of the path of the short transverse screenshot, and the thickness of the path itself should be approximately equal to the thickness of the meridians and parallels.
All gaskets and calculations are performed by a soft thinly sharpened pencil.
Places of position of the vessel on observations, i.e. According to the results of measuring the navigation parameters of external benchmarks, as often as possible and necessarily, if possible, when changing the course.
The observated places are denoted by conventional signs according to RSHS-89.
The inconsistency of the objective point with a snap is called the unclear, denoted by the letter "C". In the ship log, its direction and the value is recorded (C \u003d 225º -1.5 ')
The direction of the residuality is designed from the quality point to the observated one.
The installation of the gasket ends at the entrance of the vessel on the waterfront of the port or at the point of the beginning of the maneuvers when setting the ship anchor.
Thus, the gasket is called a set of measurements, calculations and graphic constructions associated with the choice of the ship's path, taking into account its movement and the determination of the vessel's place.
Management of graphic surgery and solution
tasks in the absence of drift and flow
The lack of a vessel drift and demolition simplifies both graphic construction on the map and calculations when solving various tasks.
Firstly, the line of the ship's path coincides with the direction of his DP, i.e. With the line IR.
Secondly, distance traveled by a vessel regarding the water ie According to the testimony of lag, corrected by its error, simultaneously is the actual distance traveled relative to the soil (S l \u003d S and).
Decision direct task
(Course Correction Tasks)
|
With a given steering KK on MK |
Same on GK |
||||||||
Defense solution
(Course Translation Tasks)
Solving private tasks
I. Application of a challenge vessel on the card.
Given: T 1, ol 1, t 2, ol 2. To find: S L.
When swimming, the ship is located on the border of two environments and water, the movement of which has an effect on it, rejecting from the course and changing the speed of movement.
The demolition of the ship by the wind is called drift. The wind is a progressive movement of air masses. For the direction of the wind, the direction (in degrees) is accepted, from where the wind blows. Wind speed is measured in meters per second or points.
Fig.1
Let the V0 velocity of the ship regarding the water due to the work of its own propellers (Fig. 1). Air resistance to the ship's movement is perceived by an observer on the ship as a counter-flow of air, whose velocity vector (-v0). Let U be - the vector of the velocity of the true wind. The counter stream of air and the true wind, folding, form a total stream, observed on a moving ship and called the seeming (observed) wind. The velocity vector of the apparent wind is equal to the geometric amount:
W \u003d u + (-v0) \u003d u - V0.
The velocity wind speed is automatically determined using an anemumbometer or manually using an anemometer, the direction of the QW is on the anemumbometer or in the direction of the flag or pennant. Apparent wind. Inactivity by the ship under the coursework QW, causes a complete aerodynamic force P, applied to the center of the ship's sailboat. Due to the refractive properties of the superstructure, the direction of the force p in general does not coincide with the direction of the apparent wind. Under the action of strength p, the ship shifts in the direction of this force with the speed of the VDD drift.
We will decompose the speed of the VDD to the components of the VDD X along the diametrical plane and the VDD Y along the traverse. The VDD X speed, depending on the direction of the apparent wind, is subtracted or consisted at a speed V0. If the lag works, it takes into account this speed. therefore
Vl \u003d V0 + VDD X.
VDD y speed deflects the ship from the specified course. After folding the geometrically vehicle speed at VDD Y, we obtain the vector V of the actual, or travel, vehicle speed:
V \u003d VL + VDD Y.
As can be seen, when the speeds are added, Vl and VDD Y, the ship moves in the direction of their relative.
The line in which the ship actually moves relative to the bottom of the sea under the action of propulsions and the apparent wind is called the line of the drift path. The diametral plane of the ship while moving it along the path line remains parallel line of the true course. This is due to the fact that the steering constantly holds the specified true course. Consequently, the ship moves along the path of the way forward is not a nose, but the cheeky.
The angle in the plane of the true horizon between the northern part of the true meridian and the line of the road during the drift is called a way angle when drieving Pu?
The angle in the plane of the true horizon between the lines of the true course and the path during the drift is called the drift angle?. If the wind blows into the left side of the ship, the drift corner is positive (travel angle with drift more than the true course). With the wind from the right side, the drift corner is negative (travel angle with drift less than the true course).
The drift angle depends on the speed and exchange angle of the apparent wind, from the speed and structural features of the ship: the heights and architectures of the add-ons, the surface part of the case and the shape of the body of the housing. The drift angle is measured using a drifomera. In the absence of this device, the drift corners for various swimming conditions are selected from the drift table, compiled according to experimental data. From fig. 1 shows:
Formulas - algebraic, corner? Takes up with his sign.
In the practice of shipments, it is necessary to solve mostly two tasks associated with the drift of the ship. Direct task:
Calculate travel angle with drift PU? (Ship path line with drift), if a true course is specified.
To solve this problem, it is necessary:
- Determine the drift corner sign?;
- Calculate the course angle QW apparent wind;
- Select the magnitude of the corner? From the argument drift table: the velocity of the ship and QW;
- Calculate the track angle when drieving PU?, Make the line path on the map.
Kk \u003d 79.0 °; Vl \u003d 12.0 bonds;
? GK \u003d + 1.0 °; Wind 5 ° -12 m / s.
Decision:
The wind blows into the left side of the ship - the angle? positive:
IR \u003d kk +? GK \u003d 80.0 °;
? \u003d + 4.0 °; PU? \u003d IR +? \u003d 84.0 °.
2. Working of true radio decks in case the radio beacon is outside the eastern or western border of the map frame.
To find the position of the determining point (T. M ') through which the radio bearing on the CRMK will be carried out (T. a), it is necessary:
one) ? From "RTSNO" to write the coordinates of Krmka (? Ah,? A);
2)? Calculate value? ? \u003d? P -? And where? P - longitude of the side frame of the card;
3)? Conduct on the map Parallel Krmeka (? A- from "RTSNO") and postpone the segment;
four) ? through t. A »Conduct additional meridian aa;
five) ? From t. A 'hold Lock. P Kmka A to intersection with aa - t. M;
6)? From t. M on AA to postpone the segment and through the resulting point M 'to hold a radio degree on the CRMK e? This will be the desired position line (I - I).