Release notes #1
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New elevation dataset.
The first elevation dataset used in the project was ETOPO1. It was very small and inaccurate, with height errors reaching up to 70 meters. The profiles of well-known mountains were far from reality. ETOPO1 has been replaced by ASTER.
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ASTER turned out to be very accurate but extremely "noisy". These noises were evident in forested areas and cities — the satellite took heights based on tree canopies and building tops.
Now, ASTER has been replaced with Mapzen.
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Mapzen Mapzen is less noisy. However, its accuracy is slightly worse than that of ASTER.
ASTER guarantees an error margin of ±7 meters. According to preliminary observations, Mapzen's error margin in certain areas may reach up to ±15 meters. But for the most part, it closely matches ASTER.
At present, it seems to be the most optimal choice. Reducing noise eliminates extra meters in the gain/loss height calculator.