Nighttime calculation

Here's an interesting visual basic (VB6) project for somebody who is interested in more interesting projects than usual straightforward stuff. What you need is to create a vb module (.bas) or class module (.cls) (your choice) (you can also make more than one as necessary) along with a small tester program to help me compute sunrise / sunset and flight time based on this. Here is the basic problem: you are given a date (corresponding to the start date) and two times of a day (in GMT): for example: 1600GMT (start) and 2100GMT (end). You are also given two pairs of LATITUDE and LONGITUDE in DECIMAL, NOT MINUTE format - for example, 39.9444583333, -81.89210527778 for zanesville ohio USA and 48.170167, 17.212667 for Bratlislava, Slovakia (these are actually coordinates of the airports). Your goal is to return the "night time (in minutes)" based on computing sunrise and sunset. Let me be more clear: you have an airplane that takes off at time A and lands at time B. It flies from airport X (Latitude X1, Longitude X2) to airport Y (Latitude Y1, Longitude Y2). How much of that flight was "at night?" To solve this, you need to first find some sunrise / sunset calculations. There are many available as javascript - google for "sunrise sunset calculations" or something like that and you will find several. You will notice that there are several "flavors" of sunrise / sunset--for example: - Begin of Nautical (= End of Astronomical) Twilight: Sun is 12 degrees below horizon - Begin of Civil (= End of Nautical) Twilight: Sun is 6 degrees below horizon - Sunrise: Sun is 0.83 degrees (= 50 arc-minutes) below horizon *(continued below)* ## Deliverables *(continued from above)* and a few more (plus corresponding definitions for sunset). So, your function will be something like: **Function ComputeNightTimeMinutes(StartDate as data, StartTimeGMT, StopTimeGMT, StartLatitutde, StartLongitutde, EndLatitude, EndLongitude, SSComputationMethod as integer, ByRef QualityOfReturn) as long** (note that if stoptime < starttime, then you can assume that it means "on the next day" - for example, if date = Dec 12, 1993 and starttime = 2300 and stoptime = 0200, then you can assume the flight was 3 hours long and ended on Dec 13) where SSComputationMethod is one of a number of constants that you have defined. Now, here's the problem: an airplane leaves New York at X and arrives in hong kong at Y - how much of this flight was at night? it's virtually impossible to tell, because you dont know anything about the route it took and/or the various speeds during the flight. If you want to be clever about it, you can ASSUME that the route is the most natural great circle and do some calculations based on this see <[login to view URL]> or google "aviation formulary"), but even so this is not very accurate. so what you must do is return QualityOfReturn as well. What is this? This is a score of 0-100 which indicates your "confidence" in this figure. For example: if startairport = endairport and all flight time is at day or all flight time is at night, then confidence can be quite high - 100%. if startairport = endairport but flight crosses a sunrise / sunset, then confidence is high but not absolute - 90% if startaiport is relatively near the end airport, then the confidence can remain high. the worst case is that where startairport is far from the destination airport. (new york to hong kong). in that case, make the quality score correspondingly low. In the end, it will not be important that this be accurate to the minute. Your code will be used in a program and will tell pilots that "we think this is what your night time was: " if it's off by 10 minutes or so, that's fine. if it's off by many hours, then the pilots who use this will be able to edit it themselves. Your functions / cls will be used in a larger projects, so must be clean with full documentation. this is a good project with somebody with good formal training in math or a related field. Thank you for your bids. Adrian **DELIVERABLES: + working VB6 code (either bas or cls), as described and well commented + some description of the choices you made. you will need to make some intelligent decisions and assumptions while doing this. let me know what they are. + a small driver program to let me test this (a few text boxes and a command button and some displayed output is fine) + Remember that your code will be used in a larger project. It must be ready for another programmer to use. ** ## Platform VB6