Investigation of Terrain Elevation Estimation of GEDI Spaceborne Laser Altimeter

Year 2024, Volume: 24 Issue: 1, 85 - 89, 27.02.2024

Ömer Gökberk Narin Mustafa Yilmaz

https://doi.org/10.35414/akufemubid.1349854

Abstract

Global Ecosystem Dynamics Investigate (GEDI) is a space-based laser altimeter system used for Earth observation in many areas such as forest cover, water level and land elevation estimation. GEDI data is affected by atmospheric effects due to the sensor used during the observation. In our study, 55 control points within GEDI points were compared in the borders of Afyonkarahisar province located in the west of Turkey. In addition, a comparison was made according to “solar_elevation” and slope in order to examine the sensitivity of GEDI data in more detail. Root Mean Squared Error (RMSE) was used as the accuracy metric for comparison. As a result, it was observed that the accuracy of GEDI data increased at night and in areas with low slope. In our study, GEDI data showed a success of 2.79 m in determining the height of the land for 55 points, and 2.34 m at 30 points with low slope at night, according to RMSE

Keywords

GEDI, GNSS, Terrain height, Satellite Altimetry

GEDI Uydu Tabanlı Lazer Altimetre Verisinin Arazi Yükseklik Tahmininin Araştırılması

Abstract

Global Ecosystem Dynamics Investigate (GEDI), orman örtüsü, su seviyesi ve arazi yüksekliği tahmini gibi birçok alanda yeryüzünün gözlemlenmesi için kullanılan uzay kaynaklı bir lazer altimetre sistemidir. GEDI verileri, gözlem sırasında kullanılan sensör nedeniyle atmosferik etkilerden etkilenmektedir. Çalışmamızda Türkiye’nin batısında yer alan Afyonkarahisar ili sınırları içerisindeki 55 kontrol noktası ile GEDI noktası karşılaştırmıştır. Ayrıca çalışmada GEDI verisinin hassasiyetinin daha detaylı incelenmesi için “solar_elevation” ve eğime göre karşılaştırma yapılmıştır. Karşılaştırma için doğruluk metriği olarak Karesel Ortalama Hata (KOH) kullanılmıştır. Sonuç olarak GEDI verisinin gece zamanlarında ve eğimin düşük olduğu alanlarda doğruluğunun arttığı görülmüştür. Çalışmamızda 55 nokta için arazi yüksekliği belirlemede GEDI verisi KOH’a göre 2.79 m, gece ve düşük eğimli 30 noktada ise 2.34 m başarı göstermiştir.

Keywords

Uydu Altimetresi, GEDI, Arazi yüksekliği, GNSS

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