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Moon tracking DLL

A DLL to provide information about the moon or sun for program developers

The functions and procedures in VK5DJ_sunmoon.dll are derived from the work of the following people.


Inputs to the DLL are:

Date as Year, Month, Day

Time as Hour, Minute, Second

Station information as Height ASL (metres) , Latitude (decimal degrees with negative for southern hemisphere), Longitude (decimal degrees with negative for West of Greenwich)

Switches for Refraction effect of light, Sun/Moon choice

Band information for Doppler calculations

Outputs from the DLL are:

Azimuth and elevation of the body from the observer's perspective

Doppler shift of body at the band entered above

Distance of the remote body from the observer

Angular diameter of the body from the observer's perspective

Right ascension of the object (geocentric) in decimal hours

Declination of the object (geocentric)

Declination of the object topocentric

Libration in frequency spread (Hz)

Right ascension in HH:MM:SS

Polarity shift for antenna between stations

Decibels of loss referenced to closest distance of object

Distance of distant (DX) station on Great Circle path

Direction of distant (DX) station on Great Circle path

Locator derived from Lat/Long

Lat/Long derived from locator

Moon phase (several formats)


Phase angle (Sun/Moon/Observer)


Version number

Ever wanted to develop some software but doing all the moon and sun calculations was just too much. This little DLL does all the work for you. The purpose of the DLL is to provide an easily used platform for the calculation of the position of the sun or the moon and to provide the associated information often required for amateur radio operators interested in EME.

Due to the use of stdcall the DLL library should work with any of Windows versions of Delphi, Visual Basic, C and versions of these compilers designed for Linux. In the Resource ZIPs I provide an example interface (Test_DLL) written in Delphi to assist developers.

Version 2.16 added illumination, phase (two formats), phase angle, quarter.

TestDLL front end- click for larger image

Download full resource

Download help file

Updated V2.16: 18 Sept 2014