Welcome to NEMETODE

Network for Meteor

Triangulation and Orbit Determination

Noteworthy

The capture software used by NEMETODE is based on the principle of motion detection - as a consequence the cameras can be triggered not just by meteors but also by other moving or changing objects within the field of view. This page is a collection of some of the more unusual observations. Sprites have their own dedicated page but these recordings fall under the category of "Hmmmm". We have more on file and will update this page in the near future.

Yaogan 17

On the 01st September 2013 the People's Republic of China launched their Yaogan 17 Reconnaissance Satellites. Officially they are for Remote Sensing though Western analysts suspect they are for military purposes and are similar to the US NOSS Satellites. The fuel dump from the spent rocket was captured on video and is discussed (rationally) here and here.

In order to reduce the number of non-meteor detections, the capture software is configured to ignore slow moving objects such as satellites but on this occasion a capture was triggered on the Ravensmoor South East camera at 00:38:50 UTC on 02nd September 2013, resulting in the following video (click on image for video). Note that the camera has been rotated clockwise in its housing by 90 degrees and so what appears to be the bottom is actually the left hand side:

Careful examination of the video shows that in addition to the three bright satelliites, there is a fainter one trailing a short distance behind. Orbital elements for the six objects resulting from the launch for the epochs immediately before and after the time of the observation were obtained from SpaceTrack and modelled using Heavensat. Object #39242 (Rocket Booster) had already passed by 6 minutes and 18 seconds earlier but the remaining five objects are within the field of view. Modelling suggests that the bright lead object is #39239 (Yaogan 17A) while the faint trailing object is #39241 (Yaogan 17C). It's not clear what the in-between objects are but the modelling places #39240 (Yaogan 17B) and the two pieces of debris (#39243 and #39244) near this position. I would like to thank Cees Bassa for his analysis and reproduce his modelling and composite image below. In addition, Cees offers the following explanation:

"I think that what you've seen is the separation of the three payloads A, B and C from their dispenser. The fact that they were so bright may well be because manouvering / venting was going on and the exhaust clouds brightened in direct sunlight."

I suspect that Cees is corrrect in his explanation. The fact that TLEs exist for all six objects prior to this observation indicates that that separation had already occurred. The unusual brightness however suggsts that there is a large reflective area in close proximity to three of the objects and Cees' explanation make the most sense.

Chiroptera

At different times of year we have various forms of nocturnal wildlife such as this example from Leeds passing through Scutum or this one from Ravenmoor passing through the Great Square of Pegasus ... a possible confirmation of the bata Pegasids?