DOUBLE STATION OBSERVATION

INTRODUCTION

With two cameras it is possible to photograph the same meteor from two different points of view. This technique is called double-station observation and allows one to calculate the 3D trajectory and orbits of the meteors around the sun. When you conduct observation with double-station photography, you have to select the locations of the two stations and the height of the aiming point above the ground to set up the cameras. Given that meteor produces a luminous phenomenon below 120 km above the ground, the height of the aiming point usually should be below this value. For an ideal geometry, the stations should be around 50-130 km apart (ideally ~70km).

GOAL

This software has been developed within the framework of CABERNET project (Camera for Better Resolution NETwork) in order to compute the orientations of cameras dedicated to double-station meteor observations. The tool takes in the coordinates of the stations and the height of the aiming point and computes all possible orientations within the chosen interval.

HOW DOES IT WORK ?

About Java

Java is an Object Oriented Programming (OOP) language. One of the main advantages of this language is that it is platform-independent: Java applications are compiled into Java Virtual Machine code called bytecode. The bytecode is machine independent and is able to run on any machine that has a Java interpreter. If you haven?t it installed on your machine yet, you can download a JRE (Java Runtime Environment) free from here : JRE

How to use the application

The program is an executable .jar file. For Windows users, once you have downloaded the application you only have to double-click on DoubleStationV2.jar to run the software. If it doesn?t run, right click on the icon and open with Java Platform SE. For Unix users, open a terminal, go to the folder where the executable jar file is saved and type the command:
java -jar DoubleStationV2.jar

Fill in the location coordinates (latitude, longitude and altitude) of the two stations. The angles are in degrees and the height in km. For decimal values, use dots and not comas. Choose minimum and maximum values for Azimuth and Elevation from station1. Elevation must be between 0 deg (but must be greater than 0 deg and 90 deg and Azimuth between 0 deg and 360 deg. Azimuth of 0 deg is North and 90 deg is East. Choose the step value for both Azimuth and Elevation, which will shows the results at that interval. This value is set at 10 degrees by default but you can choose any step between 1 deg and 20 deg. You can change the value of the height of the aiming point that is set at 100 km. The results are stored in Results.txt file in the current folder. You can change this by entering the full destination in the "Full path"

Eg for Linux: /home/user/meteor/dbstation/run1/

Eg for Windows C:\Users\meteor\dbstation\run1\

For default folder, leave this field empty. The default filename (Results.txt) can be changed.

RESULTS

In the generated Results.txt you will find the location coordinates of both stations and the height of the aiming point. The result is divided into seven columns. In the four first columns you have all possible azimuths and elevations for camera1 (from station1), all possible azimuths and elevations for camera 2 (from station2). For each combination of camera orientation you also have the distance between station1 and the aiming point (S1P), the distance between station2 and the aiming point (S2P) and the angle between S1P and S2P. Use big steps for the first run to get an idea of the appropriate angles, and then run it again with more constraints on maximum/minimum azimuth and elevation angle but with smaller steps. Running the file again with the same output file/pathname, will cause the result file to be overwritten.

DOWNLOAD

DoubleStationV2.jar

SEE ALSO : Degrees Minutes Seconds coordinates to Degrees Decimals coordinates converter (DMS2DD)

This software has been developed by Min-Kyung KWON at IMCCE during an internship (from 14th June to 30th July 2010) under Jérémie VAUBAILLON and Prakash ATREYA's supervision

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