MetRec (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 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 number of frames and a sum image from each event. MetRec is able to compute the meteor brightness, its velocity and equatorial coordinates. The software calculates the limiting magnitude and the size of the field of view covered by the camera. It is able to determine the meteor shower on the fly, and the flux density for each meteor shower.
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.
In parallel, MetRec determined the exact size of the field of view and each minute the limiting magnitude. Based on the figures, the effective collection area of the camera and the flux density of meteor showers is computed. These values can be uploaded to the VMO server for online meteor shower activity graphs.
To run MetRec you need a PC with a special frame grabber card.
The program is designed for the Matrox
Meteor/Meteor II/Meteor II MC 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. The PC should have a Pentium processor with 700 MHz (DOS/Win98) resp. 1000 MHz (Win XP) or more. 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 (DOS/Win98) resp. 256 MB (Win XP) of main memory (recommended: 128/512 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 PCI/AGP or equivalent graphics card is advised to ensure that your system is not slowed down by the graphics output. You should have at least 50 MB of free harddisc space (recommended: >10 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 was originally designed for DOS. Today it comes in two
versions: The DOS version runs both under plain DOS or in the DOS mode
of Win 95/98. The Windows version runs on Windows XP (32 bit only).
Windows XP (64 bit) / Windows Vista / Windows 7 are not
supported, because there is no driver for the Matrox
framegrabber available for these OS.
There are only marginal differences with respect to functionality under DOS and Windows.
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 is just one software that is similar and in some aspects even superiour to MetRec with respect to it's features, performance and spreading.
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 freeware. You 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.
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 for DOS and Windows or ZIP archives MetRec_51_DOS.zip (14.7 MB) and MetRec_50_W32.zip (8.0 MB) which include 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.
There is plenty of information about video meteor observation and MetRec available in the Internet. However, there is even more information in the heads of dozens skilled video observers around the world. To capture and share their knowledge and experience, we started a MetRec Wiki as a knowledge base for video observers. You are kindly invited to use the information provided there, or register and contribute further information yourself.
A number of video observers using MetRec have joined forced in the Video Meteor Network. Their aim is to create a large database of high quality single station video meteor observations world-wide.
MetRec is copyright by the author
Sirko Molau Abenstalstr. 13b D-84072 Seysdorf Germany phone : +49/8752/869437 e-mail: firstname.lastname@example.org
email@example.com; last change: August 2, 2012