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Try Debrief

This is Debrief v4 running in your browser: the same map, tool forms and results panel as the VS Code extension, and the same Python catalogue, history, tools and importers. Nothing is installed, and nothing you do or import leaves your browser.

Things to try

  • Select and run a tool. Click BLUE ONE in the outline, then Ctrl-click RED ONE. Closest approach is now on offer. Run it: the line appears on the map, the result opens beside it, and current time moves to the moment it found.
  • Look at a moment. Drag Current time at the top of the side column. Each track's position at that time is a square in its colour.
  • Narrow the time window. Drag either handle of Time window, or the band between them. The map shows the window as you drag: tracks are drawn in full within it and faintly outside it, and the tug's track, which ends at 10:35, loses its label once the window starts after that. Let go and the window is saved in the plot, but it's not a step in History, and Undo leaves it alone.
  • Play. Press ▶, or Space on any of the sliders. Choose a speed: at 60× a minute of the exercise passes each second. Playing stops at the end of the window.
  • A colleague changes the window. A colleague changes the time window, under Try, changes it as if from another computer: Debrief shows theirs and says so.
  • Compare tracks in the Tote. Under Tote, below the time controller, choose BLUE ONE as the primary and add RED ONE and a cargo ship from Add. Or right-click a track in the outline (press and hold on a touch screen) and choose Add to Tote. Each line gives the range, true bearing and relative bearing from BLUE ONE (R to port, G to starboard), and the track's own course, speed and depth. Step or play current time and they follow; a ship not yet in the exercise says when it starts. Your choice is saved with the plot, but it's not a step in History.
  • Add an annotation. Add… under Annotation, below the outline, opens a form for a line, area, circle, ellipse, label, marker or note. Type positions as you would write them (37°00.000'N 075°30.000'W), give a circle a radius and a colour, and press Add. Select it and press Change… to restyle it: each is one step in History. North arrow shows the chart's north arrow.
  • Draw on the map. Choose Area on the map's toolbar, click each corner and double-click the last; the map says ranges, bearings and the area as you go. Name it in the form and press Add. Select it and drag a corner, or Tab to a handle and use the arrow keys: each change is one step in History.
  • Clean a track. Select RED ONE and choose Put GPS glitches into the selected track under Try, then Jumps… under Track, below the outline: the jumps found are ringed on the map and listed, all ticked; untick any and Remove the rest as one step. Smooth… shows the track as smoothing would leave it before you apply it. Fixes… lists every fix: choose one (or right-click it on the map) to colour, label or comment on it.
  • Label the times. Select BLUE ONE and Ctrl-click RED ONE, then Frequencies… under Track: labels every 10 min and arrows every 5 min, one step for both. The times sit beside each track on the clock's tens; zoom out and they thin to round times, and the map says so. Choose Other… to type an interval such as 90 s or 1h30. In Fixes…, Time label makes one fix always show its time.
  • Move one fix. Select RED ONE and zoom in until each fix has a small ring: drag one, and only that fix moves; the map says how far, which way and how fast the track would now have to go to reach it and to go on, and warns when that is as fast as a jump. Letting go is one step. Or Tab to a ring and use the arrow keys, or choose Move… in Fixes… and type where it goes. OTG/DR… plots the track by dead reckoning, from its first fix by its recorded courses and speeds, or over the ground again.
  • Import a REP file. Under Import your own, choose a REP file: Debrief asks, for each track, whether it is plotted over the ground (OTG) or by dead reckoning (DR). Tick Use this choice for future track imports to be asked no more; Ask again clears it. A track plotted by dead reckoning is tagged DR in the outline and on the map.
  • Move a track. Select BLUE ONE and drag the filled square: the map says how far and which way, along geodesics. Drag the ring to rotate it about the pivot. Choose Time window on the map to move only the fixes in the window, and watch the joins jump. Drag the diamond beside a track's last fix to shear it: the first fix stays put, and the map gives the new course and speed. Choose Stretch on the map to change only its speed. Move…, Rotate…, Shear…, Stretch…, Split… (at current time) and Merge are under Track, below the outline. Each is one step in History.
  • Read the narrative. The Timeline lists every platform's log, with notes and periods, in one time order. Press play: the list follows current time, the entry it is at marked and shown beside its track on the map. Scroll the list and it stops following; Follow time starts it again. Choose an entry and current time moves to it. Filter leaves out sources and types; the search box finds words. + adds an entry: one step in History. Under Import your own, a REP file's ;NARRATIVE: lines, or a Word (.docx, .doc) or PDF narrative, read into the open plot as one step; for a document you are asked first, as legacy Debrief asked, which types of entry to read, whether only those within the plot's period, and which track a platform with none of its name is. ⋯ beside Filter holds your own view: words to highlight, whether choosing an entry moves current time, text size and wrapping, and which columns show.
  • Undo. Every change is a step in History. Undo replays the plot to the step before. Nothing is deleted: the undone step stays listed, and Redo brings it back.
  • Crash part-way through a save. This stops a save after the new plot file is written but before it replaces the old one, as a power cut would. Reopen the plot: it is exactly as it was before that save, and Debrief says a save was interrupted.
  • Add a plot file. Under Import your own, choose a Debrief plot file (.geojson), such as one a colleague sent you. Its whole history comes with it: undo, redo and going back to a step work on what they did.
  • Work alongside a colleague. A colleague changes the plot shows what happens when someone else saves a change: Debrief shows the latest and tells you. …while your next tool runs, then run a tool: Debrief asks whether to combine the changes or save yours as a new plot. It never overwrites theirs.
  • Import your own file. Choose a REP file, a legacy Debrief .dpf plot, or a Word or PDF narrative. It's read and imported in your browser, and everything that couldn't be imported is listed.

Measuring on the real Earth

Drag two positions and compare the range and bearing Debrief v4 measures with what legacy Debrief gave:

How it works

The page plays the part of VS Code. Debrief's webviews run unchanged in frames, and Debrief's Python packages run under Pyodide in a web worker, installed from the same wheels the desktop uses.

The sample exercise is copied into the browser's memory. Every change, undo and crash happens there, and is gone when you close the page.

The first start downloads Pyodide and its packages, about 16 MB, from the jsDelivr CDN (cdn.jsdelivr.net). Later visits use your browser's cache. If your network blocks the CDN, the map still works, and the page says that tools, history and import need Python.