SIMPLE BALLOON FLIGHT SIMULATION USING A SPREADSHEET

		xselldir.txt  9/1/3 N9LKY

1	Go to wyoming weathersounding web page and choose date, time and location.
2	Select all text, copy page of data and paste to a text file.
3	Open that textfile in excel - choose fixed columns and adjust to get first data.
4	Delete bottom data of report and save as excel sheet.
5	At bottom of sheet, start new columns which will be the wind data in English.
		a	Height = meters/.30348	FT
		b	Degrees= degrees	DEG
		c	Speed=knots * .86878	MPH
6	Choose an ascent rate - typically AR=1000 ft/min - copy to sheet
7	Enter row for time zero (launch) at 0 height (or LS elv), and X=0 & Y=0
8	Calculate time (MIN)  in that layer by del T = del height / AR 
9	Calculate distance (miles) traveled by del D = SPD * del T / 60.
10	Resolve into X (East) and Y (North) components
		x = - del D *sin (dir)	where dir is deg*pi/180 radians
		y = - del D *cos (dir)	where dir is deg*pi/180 radians
11	Keep running sums:
		T	Time	sum of del T
		X	East 	sum of del X
		Y	North	sum of del Y
12	Distance from launch site is sqrt (X^2+ Y^2) in miles.
13	Copy rows until hit choosen burst height(BH=~90K).
14	Choose level chute will grab - (CH=~30 Kft).
15	Calculate freefall time by Tff= SQRT(2*(BH-CH)/(32.17*60) in minutes.
16	For the descent, copy over wind data (could be data from landing zone) at CH.
17	Choose descent rate (DR=800 ) and copy to sheet.
18	Enter start of descent location and time=BurstTtime+Tff minutes.
19	Calculate time (MIN)  in that layer by del T = del height / DR
20	Calculate distance (miles) traveled by del D = SPD * del T / 60.
21	Resolve into X (East) and Y (North) components
		x = - del D *sin (dir)	where dir is deg*pi/180 radians
		y = - del D *cos (dir)	where dir is deg*pi/180 radians
22	Keep running sums:
		T	Time	sum of del T
		X	East 	sum of del X
		Y	North	sum of del Y
23	Distance from launch site is sqrt (X^2+ Y^2) in miles.
24	Copy rows down unitl 0 (or LZ height).
25	Several important things can be read from sheet:
		Burst - Time and Location
		Landing - Time and Location
26	Several interseting graphs are obtained by selecting columns and scatter graphing them:
		Wind Profiles - Speed and Direction vs Height
		Ascent & Descent Paths - Flight Map in miles
27	Can vary paratmeters AR, DR, BH, CH to see effects on Burst and Landing.