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PA3BNX > TECH     02.07.06 21:59l 74 Lines 2032 Bytes #999 (0) @ WW
BID : 19443_PI8SHB
Read: GUEST DL1LCA DL8ZX DK2ZA DK5MH
Subj: Help with Formulas.
Path: DB0FHN<DB0FOR<DB0SIF<DB0IDN<DB0MW<DB0SWR<DK0WUE<7M3TJZ<ON0AR<PI8ZAA<
      PI8SHB
Sent: 060628/1100Z @:PI8SHB.#NBO.NLD.EU #:19443 ['s-Hertogenbosch] $:19443_PI8S
From: PA3BNX@PI8SHB.#NBO.NLD.EU
To  : TECH@WW

Hello All,

I am searching for help.
------------------------
I have build DopplerRadioDirection finder.
I have GPS Latitude/Longitude, true North and relative DopplerBearings.
I have Bearings from Position1 and Position2.

I have position1: latitudepos1, longitudepos1 from GPS Data.
       position2: latitudepos2, longitudepos1 from GPS Data.

I recalc this to Decimal Degrees. 
With N=+,S=-,E=+,W=-

With this I can calculate the distance pos1 to pos2 and the azimuth.
Earth Radius is ca 6367Km.

''--------------------------------------------------
''Distance between pos1 and pos2.
Rad= Pi/180
Long1 = LongPos1 * Rad
Long2 = LongPos2 * Rad
n1 = Atn(Tan(pos1n))
n2 = Atn(Tan(pos2n))
co = Cos(Long1 - Long2) * (Cos(n1) * Cos(n2)) + (Sin(n1) * Sin(n2))
ca = Atn(Abs((1 - (co ^ 2)) / co) ^ 0.5)
If co < 0 Then ca = Pi - ca
Dist12 = RadiusEarth * ca 

''Azimuth.
si = Sin(Long2 - Long1) * Cos(n2) * Cos(n1)
co = Sin(n2) - Sin(n1) * Cos(ca)
Azimuth = Atn(Abs(si / co))
  
If co < 0 Then Azimuth = Pi - Azimuth
If si < 0 Then Azimuth = -Azimuth
If Azimuth < 0 Then Azimuth = Azimuth + (2 * Pi)
  
Azimuth = Azimuth / Rad
''--------------------------------------------------

Okay now I have the distance pos1 to pos2 in Km 
and the azimuth in degrees from pos1 to pos2. 

I have directions from my dopplerdirection equipment. 
 
1:absolutebearing1 from pos1.
2:absolutebearing2 from pos2.

This are bearingsangles in degrees from true north. 
 
0 degrees = North 
90 degrees = West
180 degrees = South 
270 degrees = East.

========================================================
Wanted:
I want to calculate the latitude and longitude from the
fix point and I want the distance from pos2 to fix.
========================================================
I tried a lot but didn't succeed yet in getting it right in
formulas.

So any help would be very much welcome to calculate.  
1:The lat/long from the fix.
2:The distance between pos2 and fix. 

Tnx's from Lodewijk PA3BNX@PI8SHB  



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