## 1 Introduction  
Due to environmental changes and human activities, there is an increasing need for continuous monitoring of Earth's surface to observe phenomena such as urbanization, landslides, and glacier activities. The use of multi-temporal DEMs allows for the determination of, for example, changes in glacier extent and mass balances [1, 2, 3, 4]. Freely available DEMs provide global elevation information but at a ground sampling distance (GSD) of approximately 30 m per pixel using merged data captured over several days, e.g., the SRTM DEM [5] or the Open Copernicus DEM [6]. Moreover, the temporal resolution of such DEMs is frequently inadequate for the analysis of dynamic processes. The well-known ASTER system, carried by the Terra satellite, captures panchromatic stereo images for 3D processing with revisit times of 4-16 days but with limited GSD of about 15 m per pixel. Commercial very high-resolution (VHR) satellite images offer stereo capabilities, e.g., WorldView-2/3 [7, 8, 9, 10] or Pleiades [11], and enable DEMs with GSDs in the range of about a meter. However, the data are rather expensive, especially in terms of change detection, as at least two DEMs taken at two different times covering the time span to be studied are required. The same applies to on-demand constellations such as Pleiades Neo, which are capable of acquiring scheduled VHR stereo image pairs. PlanetScope, operated by Planet Labs PBC, is a constellation of Earth observation satellites designed to continuously monitor Earth's surface. The company's goal is to provide frequent and easily accessible satellite imagery for various applications, such as environmental monitoring, agriculture, urban planning, and disaster prevention. Particularly interesting for many scientific questions is the fact that the data are free of charge for non-commercial purposes, e.g., via the ESA Earthnet Programme ([[https://earth.esa.int/eogateway/catalog/planetscope-full-archive](https://earth.esa.int/eogateway/catalog/planetscope-full-archive)]([https://earth.esa.int/eogateway/catalog/planetscope-full-archive](https://earth.esa.int/eogateway/catalog/planetscope-full-archive)), accessed on 18 February 2025) or the Planet Education and Research Programme ([[https://www.planet.com/industries/education-and-research/](https://www.planet.com/industries/education-and-research/)]([https://www.planet.com/industries/education-and-research/](https://www.planet.com/industries/education-and-research/)), accessed on 18 February 2025). The PlanetScope constellation currently consists of approximately 130 low-cost cubesats, called _Doves_, which operate in sun-synchronous ascending and descending orbits while Earth rotates underneath, allowing for gap-less mapping of Earth's surface at daily resolutions (see Figure 1). _Doves_ are composed of adapted components from miniaturized consumer electronics [13]. The high-resolution push-frame imaging system consists of a frame camera charge-coupled device (CCD) sensor and a mirror telescope lens capturing Earth's surface with a GSD of 3-4 m. In this push-frame system, wavelengths are separated from each other by filter masks so that specific parts of the sensor are only affected by certain wavelengths, enabling multi-spectral imaging. The individual sub-frames are assembled by band co-registration into complete scenes according to the sensor resolution in the factory post-processing. Depending on the cubesat generation, the (full) CCD sensor has a spatial resolution of approximately 6660 \(\times\) 2220 pixels (first _Dove Classic_ generation) or 6660 \(\times\) 4400 pixels (second _Dove-R_ and third _SuperDove_ generation), which results in footprints of 24 \(\times\) 8 and 24 \(\times\) 16 kilometers, respectively. The spectral resolution of _Dove Classic_ and _Dove-R_ was limited to RGB and near-infrared (NIR). _SuperDove_ additionally resolves red edge, coastal blue, yellow, and a small band in the range of green.