Dead Reckoning — Survey Notes
These notes describe the Dead Reckoning survey facility of EDWARD, a DCS World simulator modification for the De Havilland Mosquito F.B. Mk. VI. They are complementary to the Edward Menu Notes and assume a thorough knowledge of its contents. They are prepared for the guidance of the player only, and create no obligation beyond the simulator itself.
Notes to users
1. Complementary publication
These notes are complementary to the Edward Menu Notes and assume a thorough knowledge of its contents, and that EDWARD has already been installed and found to be working correctly.
2. Nature of this publication
This publication describes EDWARD, a DCS World simulator modification for the Mosquito F.B. Mk. VI, and not the aeroplane itself; nothing in it creates any obligation beyond the simulator.
3. Conventions
Throughout this publication the following conventions apply:— words in capital letters indicate the actual wording shown upon a menu wedge, or, where marked DR - or FP -, upon an F10 map mark; these prefixes are not to be altered.
4. Binding force
The limitations quoted in Part III are mandatory. The contents of the other parts are mainly advisory, but instructions containing the words “is to be” and “are to be” are also mandatory.
5. Phase 1 only
This publication describes Phase 1 of the Dead Reckoning facility only. The automatic selection of Dead Reckoning points during a live sortie (Phase 2) has not yet been brought into service; see Operating Data.
6. The player
Throughout, “the player” denotes the person at the controls.
Check list — By D.R. Landmarks
By D.R. Landmarks —
Status/action wedge ....... As marked; see para. 10
Clear DR Marks ............. Clears F10 marks. Point list and file unaffected
Re-survey Theatre .......... Surveys again. Asks once; file unaffected until Save
Go Back ..................... Returns to Navigation
Part I — Descriptive
7. Dead Reckoning points
Dead Reckoning points (D.R. points) are landmarks — churches, bridges, railway stations and depots, rail junctions and yards, water crossings, bunkers and radar stations, stadiums, and airfields — collected for a theatre so that EDWARD may take a fix upon them in flight. Each theatre's points are held in a file of its own, one file to a theatre, at Scripts\Edward\DRPoints\<theatre>.lua. Points placed by the player (para. 9) are held apart from these, in <theatre>_user.lua beside it, so that a fresh survey of the theatre never disturbs them.
8. Classification
Each point is classified Low, Medium, or High, according to how close a landmark must be approached before it can be trusted as a fix. Medium is given automatically unless a point is placed by hand with the band stated; a hand-placed point left unmarked for band is also Medium. See Operating Data for how this classification is intended to be used once brought into service.
9. Points placed by hand
A landmark may also be added directly by the player: an ordinary F10 map mark whose text begins FP -, e.g. FP - Church. Such a point is accepted without question; EDWARD does not verify what is on the ground there. If the player states a band — FP - Church - Low — the point is intended to be treated exactly as an automatic point of that band once Operating Data is brought into service; if no band is stated, Medium is given as for any other point. In a mission, such a point loses its FP - prefix and any band, and is shown simply as, e.g., DR - Church, exactly as an automatically found point.
10. The status/action wedge
The status/action wedge under is marked CREATE DR POINTS, SURVEYING NN%, VIEW ON MAP (N), SAVE (N UNSAVED), or SAVE DR POINTS, according to the state of the theatre's survey. Words in capital letters indicate the actual wording shown upon the wedge. See Part II for the sequence in which each marking is reached.
The centre of the ring carries two counts, which are not the same thing. N POINTS is the number held in the theatre's list; N ON MAP, or MAP CLEAR, is the number at present drawn upon the F10 map. CLEAR DR MARKS alters the second only.
Where the theatre has already been surveyed, a further wedge is marked RE-SURVEY THEATRE (para. 12(iv)).
Part II — Handling
11. Preparing the mission
A theatre is surveyed once only, not on every sortie. Before the survey is begun, a mission should be prepared consisting of the Mosquito alone, cold at any airfield on the theatre concerned, with no route and no other unit placed.
Note.— The survey facility is made available only in a mission holding exactly one unit, and that unit a Mosquito. In any other mission the markings CREATE DR POINTS and SAVE are not shown, and the wedge offers VIEW ON MAP alone; the theatre's file cannot then be overwritten by an accidental selection in the course of an ordinary sortie.
12. Opening the survey
(i) Fly is to be clicked to enter the cockpit, as for any mission; there is no need to take off.
(ii) The Edward Menu (not DCS's own radio menu) is to be opened and selected.
(iii) If the theatre has not before been surveyed, the wedge is marked CREATE DR POINTS. It should be clicked once only: EDWARD then tiles the whole theatre with an anchor approximately every 5 n.m. and searches about each of these automatically, and the wedge marking changes to SURVEYING NN% while this proceeds.
(iv) If the theatre has already been surveyed, the wedge is marked VIEW ON MAP (N), N being the number of points already held; clicking it places them upon the F10 map without altering the file. A further automatic search of the same theatre is to be had from the wedge marked RE-SURVEY THEATRE, which is shown alongside it. This wedge asks before it acts: upon the first click it is re-marked CONFIRM RE-SURVEY and the menu is closed; the ring is to be re-opened and the wedge clicked a second time within fifteen seconds, after which the marking reverts and nothing is done.
Note.— A re-survey replaces the points held in memory, the player's own FP - points (para. 9) excepted, which are carried across. The theatre's file upon disk is not touched until SAVE is clicked, and the previous file is then preserved as .bak. A re-survey whose result is not wanted is therefore undone by reloading the mission without saving.
13. During the survey
(i) Nothing further need be done; the search proceeds of itself while EDWARD works through the theatre, and results appear upon the F10 map as they are found.
(ii) A large theatre may take some while, EDWARD working through it methodically rather than by following anything the player does.
(iii) Curation (para. 14) may be begun upon points already found without waiting for the whole theatre to be finished.
14. Curating the map
Once points appear, the F10 map is the working copy, and is to be edited directly before saving:
(i) A point wrongly placed is to be deleted like any other F10 mark.
(ii) A landmark missed by the automatic search may be added by hand, as an FP - mark (para. 9).
(iii) A badly placed automatic point is corrected by combining (i) and (ii): the bad mark deleted, a fresh FP - mark added in its place.
(iv) There is no facility to discard curation directly; leaving the mission without saving has the same effect (Part IV).
15. Saving
The wedge, once any point has been added or deleted, is marked SAVE (N UNSAVED) — N being the number of changes pending, not the total held — or SAVE DR POINTS where the changes pending net to none. Clicking it writes the F10 map's present state to the theatre's file. This is to be understood as a replacement of the whole file, not a merger of it with what is on the map (Part III). A single backup of the previous file is kept, as <theatre>.lua.bak; it should not be relied upon for more than the one save immediately before it (Part III). Saving at intervals during a long survey, rather than only at the end, is recommended.
16. Ending the survey
Once saved, nothing further need be done; the mission may be left. The same sequence, beginning again at VIEW ON MAP, may be returned to at any time to curate the theatre further.
Part III — Limitations
The following limitations are to be observed during all conditions of use of the Dead Reckoning survey facility:—
17. Saving replaces, it does not merge
Saving is to be understood as replacing the whole of a theatre's Dead Reckoning Points file with exactly what stands upon the F10 map at the moment SAVE is clicked; there is no facility for merging old and new. The player is to satisfy himself that the map is correct — points wrongly placed removed, points missed added — before saving, not after.
18. One backup only
A single generation of backup only is kept for each file (<theatre>.lua.bak and <theatre>_user.lua.bak); each is overwritten at every subsequent save and does not accumulate. It is not to be relied upon to recover more than the one save immediately before it.
19. Theatre-wide, not route-specific
A survey covers the whole of the theatre in a single pass, not merely the neighbourhood of any one route. The Dead Reckoning Points file is common to every mission flown afterward upon that theatre, and is not to be confused with data belonging to any one mission.
20. Theatres provided for
Theatre boundaries are known in advance for the following theatres only: Afghanistan, Caucasus, the Falklands, Germany (Cold War), Iraq, Kola, the Mariana Islands, the Marianas (WWII), Nevada, Normandy, the Persian Gulf, Sinai, Syria, and The Channel. Of these, Normandy and Syria have been surveyed.
Part IV — Emergencies
21. Interruption of the search
Should the player click the status/action wedge while SURVEYING NN% is shown, no further action is taken beyond a report of the percentage completed; the search is not to be started twice, and cannot be hastened by repeated clicking.
22. Leaving before saving
Should the mission be left, or DCS closed, before SAVE has been clicked, the theatre's file on disk remains exactly as it stood before the survey was begun; no curation done in that session is lost from the file, because none of it was ever written to it. Nor can it be recovered for a later session: a mission left unsaved must be curated afresh from what the map then shows.
23. Recovery from a wrong deletion
A point deleted in error is not restored automatically. It is to be replaced by hand, as a fresh FP - mark placed in the same position (para. 9); it will then be treated as any other player-placed point once saved.
24. Recovery from a bad save
Should a save prove to have been made in error, the single backup described in para. 18 is the only recourse, and only for the save immediately preceding it. Beyond that, there is no facility for recovery, and a fresh survey (para. 12) is the only remedy.
Part V — The points in use
25. General
What follows is in service and requires no action by the player. It applies in an ordinary mission on a surveyed theatre — that is, in any mission which is not itself a survey.
26. Automatic selection
Upon a mission being loaded on a surveyed theatre, EDWARD examines the theatre's Dead Reckoning Points file for those points lying near the route to be flown and marks the useful ones upon the F10 map, without the player's intervention. The theatre-wide VIEW ON MAP wedge is withdrawn in a real mission: it is a survey instrument, and the whole theatre is of no use to a crew in the air.
The wedge in its place reads VIEW MISSION DR POINTS ON MAP and, once used, CLICK TO RE-PICK FOR CURRENT ROUTE. A re-pick works upon the route as it now stands, so an alteration made in the air is taken up.
27. Selection by height
A point is offered according to the height at which that leg is to be flown, taken as the mean height above ground of its two waypoints:—
(i) Below 3,000 ft. A.G.L., points of every band are offered, the nearest to track winning, out to 2½ miles.
(ii) Between 3,000 ft. and 12,000 ft. A.G.L., points of every band are offered between a half and three miles of track, an offset of about a mile and a half preferred; a small feature lying directly beneath the track is set aside in favour of one to a side, a large and unmistakable feature excepted.
(iii) Above 12,000 ft. A.G.L., Low points are withheld — a feature without surroundings cannot be read from that height — and Medium and High points are offered out to five miles.
(iv) A point placed by hand is offered regardless of the ordinary spacing, claims its place upon the leg, and sets aside any automatic point within a mile of it in an overlapping band.
(v) No point is offered within fifteen miles of the first waypoint or five of the last.
28. The call in the air
EDWARD makes two calls upon each selected point.
The warning, about a minute before the point comes abeam, so that the crew know what to look for and on which side:—
Edward: Pinpoint in one minute - Rail Yard, about 1 mile to starboard.
The fix, as the point passes, giving the time against the plan and the aircraft's displacement from the intended track:—
Edward: There is Rail Yard, 1 mile to starboard. On time, on track.
Edward: There is Rail Yard, 1 mile to starboard. 1min 10 seconds late, and we passed 1.1 NM port of track.
Both calls give the distance out to the landmark, to the nearest half mile (or half kilometre, where Settings has kilometres), so that the eye may be put upon it; a landmark passing within a quarter of a mile is called “close”. The warning's figure is that expected upon the present track, the fix's the nearest the aircraft actually came.
The displacement is obtained by comparing where the landmark was planned to pass against where it did pass, and is a fix upon the aircraft's position — not a comparison of headings. The correction itself is left to the existing off-track and schedule calls, which are not to be duplicated.
The name given is the point's own label, exactly as it appears upon its F10 mark, so that call and mark may not be confused.
29. When no call is made
(i) A landmark passed too wide to have been seen is not called. Low points are called within one mile, Medium within three, High within eight, measured from where the aircraft actually went. The omission is deliberate: if a landmark is not seen, the crew are to stick to their courses and times and wait for the next, not hunt for it.
(ii) No call is made while nav updates are switched off, during a bombing run, or while EDWARD is counting down a turn. A call falling in such a moment is held and made when he is free, or abandoned if it has gone stale.
(iii) Calls are spaced, and only one is made at a time.
(iv) The time is stated only where the mission carries planned times. Where the Mission Editor has set none, the landmark and the displacement are given and nothing is said of the clock — a time invented from an assumed speed being worse than none.
(v) Clearing the D.R. marks from the map does not stop the calls. The marks are a convenience upon the chart; the calls are the navigator's work, and the landmark is to be looked for out of the window.