View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0002070 | SkyChart | 1-Software | public | 19-02-03 12:58 | 19-02-03 17:34 |
| Reporter | Sasa | Assigned To | |||
| Priority | normal | Severity | minor | Reproducibility | always |
| Status | new | Resolution | open | ||
| Platform | Linux | OS | Ubuntu 64-bit | OS Version | 18.10 |
| Product Version | 4.1 SVN | ||||
| Summary | 0002070: Zoom in/out - time changes but position is fixed (Alt/Az) | ||||
| Description | IIRC, long time ago is set that on zoom in/out time is stopped, in order to avoid problems when FOV is quite small (i.e. desired object is near). However, it seems that on the graph, current time is always displayed on mouse wheel change, even position is fixed. | ||||
| Steps To Reproduce | 1. Default ini after installation 2. Ensure Jupiter is over horizon!. Search for Jupiter in edit field, press ENTER and do not lock on it. 3. Zoom in with mouse wheel and compare time on graph and position on center Time WILL change , but Jupiter is always in screen center. | ||||
| Additional Information | Notice another situation: 1. Default ini after installation 2. Ensure Jupiter is UNDER horizon! (set time when it is under horizon). Search for Jupiter in edit field, press ENTER and do not lock on it. 3. Press icon to show object under shorizons 4. Zoom in with mouse wheel and compare time on graph and position on center Time will NOT change, nor position during zooming in/out. I.e., in this situation works as intended. | ||||
| Tags | No tags attached. | ||||
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I think this is how it is expected to work. Time changing or not depend on the FOV when you zoom, the time do not change when the FOV is smaller than 10 arcmin. This was your request to keep the small planet satellite centered with narrow zoom. Otherwise the satellite move out of the field because of it's own movement. This is the same in Alt/Az or EQ projection. Then in Alt/Az projection the field center remain constant in RA,DEC when you zoom and this for any FOV. This is to keep the field of view constant when you zoom and prevent the target to get out because of the Earth rotation. This is the same as the view in a telescope with RA tracking. When the time is changed using the Now button, or a time refresh event, it keep the Alt/Az position and the objects move in the field the same way as in a telescope with the RA motor stopped. Do this explain all your observation? |
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Time should be keep still when zoom in/out, regardless searched object is under or over horizon. I believe all should be keep still when zoom regardless FOV. If just under 10 arcmin, then now it fix position by changing time on chart regardless FOV, but all is fine only if object is under horizon. Shown time do not change position - it probably recalculate chart on that fixed position and time, but still show current computer time when wheel event happened. IIRC, there is several different JD. Perhaps it is drawn wrong one if object is over horizon? I remember statements in the code was rather complex and perhaps some parenthesis and/or additional statement missing in case for over/under horizon object when it is on the screen center. NOW button seems to recalculate and redraw all correctly, but it is weird when zooming only, as explained. |
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To simplify maximally: try to zoom in/out from FOV 45 to near 0 and you will for sure notice some weirdness - position will not change regarding shown time when searched object is under or over horizon. |
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It not make any difference when the object is above or below the horizon. The difference between your first and second example with Jupiter is because in the second case (under horizon) you explicitly set the time. When you set a given time in the program it is no more updated until you set another time or click the Now button to return in real time, or use the same options in the time setting dialog. |
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" try to zoom in/out from FOV 45 to near 0 " : This is what I explain above, when zooming in alt/az mode the center RA/DEC is conserved, not the Alt/Az center. This is very important to not loss an object when you are observing at the telescope. But if you do the same very near the west horizon, you see the horizon line to climb up in the screen very time you zoom. The proof the new time is really taken into account. |
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It is a bit different situation without telescope and that make all really complicated... We have: 1. System time checkbox 2. Auto-refresh checkbox (60 sec period by default) 3. Manual time set or button set (prev, now, next, pause etc..) 4. Telescope 5. Object under/over horizon Of course, some actions are pointless with telescope, but very useful with manual time set searching and looking for some events in the past and future and vice-verse... All that gives too many combinations which is very hard to handle at once and everyone taste and need. Thus code may become quite complicated and may require some a bit more serious reconsideration. |
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Yes this is a lot of option but I already try to make it as clear as possible. For example you cannot specify another time if "use system time" is checked, and "auto-refresh" is disabled if you uncheck "use system time". If you increment the time from the toolbar this automatically disable "use system time", when you click the Now button this enable it, and the auto-refresh if configured. It was requested the "auto-refresh" can be disabled when near real time is necessary but you not want an unexpected refresh and time change in the middle of the chart adjustment. And I know users that never want time auto-refresh but rely on the fact the time change when the chart is moved. This is why I was a bit reluctant when you asked to not change the time when zooming, this 10' limit is a compromise for that. When you set the chart for observation in the past or future this is very clear, the time will never change on it's own. You have to set a new date in date/time box, or use the time arrow in the toolbar. If you want to simulate the sky movement at another date you can use the animation feature. Yes the code is a bit complex because of all this additions over the time, it is possible to make it cleaner but for now it work as expected. And this is only a small part of all the processing it do on every chart refresh . If you want to experiment with other options look for the "newtime" parameter of Tf_chart.Refresh() and Tskychart.Refresh(). |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 19-02-03 12:58 | Sasa | New Issue | |
| 19-02-03 14:31 | Patrick Chevalley | Note Added: 0005306 | |
| 19-02-03 15:10 | Sasa | Note Added: 0005308 | |
| 19-02-03 15:18 | Sasa | Note Added: 0005309 | |
| 19-02-03 15:34 | Patrick Chevalley | Note Added: 0005310 | |
| 19-02-03 15:50 | Patrick Chevalley | Note Added: 0005311 | |
| 19-02-03 16:28 | Sasa | Note Added: 0005312 | |
| 19-02-03 17:34 | Patrick Chevalley | Note Added: 0005315 |
