StrewnLAB is a computer program for predicting meteorite strewn fields, written by Jim Goodall, the President of the General Motors Astronomy Club. The script is written in the MATLAB computing environment, and it simulates the entire flight of meteoroids through the atmosphere, from entry to landing. StrewnLAB differs from most existing meteor flight simulations, because it has the following features:
- Detailed weather data analysis – StrewnLAB automatically pulls data from the Integrated Global Radiosonde Archive (IGRA), from multiple stations, predicts a weather balloon flight path and and then interpolates in 4 dimensions to find wind speed along the path of the meteor. The model also estimates weather variation across the region and predicts a minumum and maximum possible wind speed.
- Models the entire flight path, including ablation and fragmentation, not just dark flight – The advantage is that it does not assume all fragments start from a single point (dark flight), so this enables a wider variety of masses landing in the same area, which is more realistic.
- Monte Carlo scenario simulation, to capture all the known variation – No meteor trajectory is known perfectly, and StrewnLAB takes into account all the known variation in a witnessed fall, including error in latitude, longitude, dark flight altitude, bearing, slope, wind speed, entry mass, and meteoroid density.
- Random Fragmentation – Detailed fragmentation models are not necessary to comprehend the strewn field, and this information is usually unknown anyway. Instead, StrewnLAB creates many random fragmentation models and plots all the results to capture the realm of possibility.
- Larger, More Realistic Mass Zones – because of the reasons listed above, StrewnLAB is capable of generating larger zones for each mass range (10 gram, 100 gram, 1 kg, etc), which actually have a lot of overlap.
- Find Probability Maps – StrewnLAB takes the results of all the Monte Carlo scenarios and generates a color shaded probability map, intended specifically for meteorite hunting. The map output indicates the best areas to search, with the highest probability of finding meteorites on the ground.
Jim Goodall wrote the original script for StrewnLAB in April of 2018, in response to the Hamburg Meteor, which fell only 30 km from his house in southeast Michigan. Since then, Jim has greatly expanded the capabilities of the program and the output has been validated against several popular witnessed falls, including Park Forest, Sutters Mill, and Chelyabinsk, with more than satisfactory results.
To see an example simulation in action, please visit YouTube and play the following video: Hamburg Meteor – Monte Carlo Simulation in MATLAB For best results, it should be viewed in 1080p on a monitor (not a phone). In the video, you can see how meteor fragments are greatly affected by wind, once they get into the troposphere.
