![[Japanese Documentation]](japanese.gif)
Japanese MetRec DocumentationMetRec (Meteor Recognizer) is a software package for the automatic detection and analysis of video meteors. In can be used both to inspect video tapes offline, and to do online recognition for an automatic video meteor camera.
MetRec analyses in real-time half resolution grey scale PAL (384x288 pixel, 8 bit) or NTSC (320x240 pixel, 8 bit) video frames at rates up to 25/30 frames per second. It stores the appearance time of meteors and optionally a sum image and an animation from each event. MetRec is able to compute the meteors brightness, its velocity and equatorial coordinates, and to determine the meteor shower it belongs to.
The software is highly flexible - it can be adapted to each individual system with a number of parameters to be set in a configuration file. All output is written into a logfile or sent to a printer. During recognition, the current input signal and the system state is displayed at the computer monitor.
MetRec uses a complex algorithm to detect even faint meteors and minimize the false detection rate. Here only a short overview is given. Please, refer to the ReadMe file for a more detailed description.
The program digitizes video frames and subtracts a mean image at first. This way all stationary objects like stars and terrestrial light sources are removed, and only noise and fast moving objects remain. Next the noise variance is normalized ("flatfielding") to ensure constant meteor detection probability in the full field of view.
MetRec then looks for bright elongated spots in the resulting image. If their brightness is above a certain threshold a meteor is hypothesized. The software compares the position of these spot(s) in the current frame with those of similar objects in the previous frame(s) in order to track the meteor. If an object has the right velocity for a meteor and was found in at least a prespecified minimum number of video frames, a meteor is detected.
After the meteor disappeared, MetRec computes the equatorial coordinates of its position in the individual video frames, derives a mean meteor trail, and calculates the velocity and brightness of the meteor. The software checks whether it belonged to one of the showers from IMO's working list. Finally a logfile entry, a sum image of the meteor, a short animation, and a PosDat file entry can be generated and saved.
To run MetRec you need a fast PC with a special frame grabber card.
The program is designed for the Matrox
Meteor/Meteor II frame grabber family.
Drivers or additional software from Matrox are not required.
MetRec neither works with TV cards or any
frame grabber from a different vendor, nor is it able to read AVI or other
video files.
The program expects a PAL or NTSC video signal at the frame grabber input. For good recognition performance, a PC with a 166 MHz or faster Pentium processor (recommended: >500 MHz) is required. The program will run on slower machines, too. However, this will result in a reduced frame inspection rate causing seriously degraded recognition performance.
MetRec requires at least 16 MB of main memory (recommended: 128 MB). The software runs at a graphics resolution of 1024x768 pixels and therefore requires a graphics card with at least 1 MB memory installed. A fast PCI graphics card like Matrox Millenium is advised to ensure that your system is not slowed down by the graphics output. You should have at least 25 MB of free harddisc space (recommended: 1 GB). When you intend to save meteor frames, a disc space of the expected meteor number times the number of frames per event times 100 kByte is required.
The program is designed for Dos. It runs both under plain Dos or in the Dos mode of Win 95/98. It does not work under Windows NT, XP, ME, W2K, W2K3 or Vista/Longhorn.
If you setup your camera for the first time or changed the field of view, you need to grab a reference image and measure the position of a number of reference stars to allow for the equatorial coordinate conversion. With the help of the RefStars tool this takes about 10 minutes.
Next you copy and old MetRec configuration file, update a few entries if necessary and start MetRec. The detection software runs autonomous, but you can interactively check the current recognition status and detection results. The program displays both the raw video data stream and different phases of the detection process in real time.
At the end of observation the PostProc tool helps you to browse through the list of detected meteors and to delete false detections in a comfortable way. This takes usually another 5 to 10 minutes.
There are further screen shots for the different programs available which give an idea of the appearance of the software. A description of these shots can be found in the ReadMe file.
To my knowledge, there are currently two other software packages for the automatic detection of meteors. MeteorScan by Pete Gural was designed for Apple MacIntosh computers. It has a different Hough transform based meteor detection algorithm, but is similar to MetRec with respect to it's features and performance.
UFOCapture by the Japanese programmer SonotaCo is a program to detect different types of moving object in the night sky (meteors, satellites, sprites, etc.). It runs on PCs under Windows and comes with additional tools for detailed meteor analysis up to orbit determination from multi-station observations.
MetRec is shareware. Amateur astronomers may copy, use, and redistribute the software free of charge. However, the author would like to get a short message from everybody using MetRec to know, which versions of the software are used where.
Professional or commercial users are required to register with the author and pay a registration fee of 250 Euro. Please, contact the author for detailed payment instructions.
For research purposes, you may obtain the documented C source code of MetRec at request from the author.
MetRec can be downloaded from this site or from IMO's ftp server. You have to choice to download the individual program files of the ZIP archive install.zip (11.9 MB) which includes the full software package in compressed format. The history file informs you about the latest software changes.
There is a mailing list for questions and announcements (bug reports, software updates) regarding MetRec, as well as for general discussions on video meteor observation. You can subscribe/unsubscribe to that list and browse the list archive at http://groups.yahoo.com/group/metrec
MetRec is copyright by the author
Sirko Molau Abenstalstr. 13b D-84072 Seysdorf Germany phone : +49/8752/869437 e-mail: sirko@molau.de
webmaster@metrec.org; last change: December 21, 2007
