EXOTOPO The data consists in topographic maps of synthetic 3D bodies generated by a 3 parameters statistical model : the fractionally integrated flux (FiF) (Lavallée et al 1993) adapted for in spherical coordinates (Landais et al., 2018). The 3 parameters are the following : H : degree of smoothness C1 : degree of intermittency alpha : degree of multifractality Detailed information about the fractionally integrated flux model can be found in Lavallée et al 1993. We adapted the model on a spherical geometry (Landais et al 2018) and wish to provide in this archive some example of the model output.The synthetic topographic maps consist in 5000x10000 lat-long grids that contained elevation data. Combined to a radius that can be freely chosen, each grid may be used to construct a 3-D shape of a planet-like or asteroid-like body. We aimed to illustrate the impact of a variation of H (degree of roughness) and C1 (degree of intermittency) for a typical value of alpha (alpha=2). Hence each map has alpha = 2, H = {0.4 0.7 1.0} and C1 ={0.00 0.05 0.10}. Additionally, we compute the same simulations with various random seed (S=01, 02, 03....). Data are distributed in archives grouped by random seed identifier. Two kind of files are present : 1) hdf5 files containing topographic map represented as a lat-long grid. The topographic map is inside the .hdf5 file in the dataset "/data". Parameters are recorded in the metadata. The latitude sampling is inside the .hdf5 file in the dataset "/lat". The longitude sampling is inside the .hdf5 file in the dataset "/long". Topography nomenclature : S{seed id}_A{value of alpha x10}_C{value of C1 x100}_H{value of H x10}_LAT{latitude sampling}_LON{longitude sampling}_TOPO.hdf5 - Example : S01_A20_C00_H04_LAT_5000_LON10000_TOPO.hdf5 contains a 5000x10000 double lat-long map with a random seed identified by : "01", ALPHA =2, C1=0.0 and H=0.4 - Example : S01_A20_C10_H10_LAT_5000_LON10000_TOPO.hdf5 contains a 5000x10000 double lat-long map with a random seed identified by : "01", ALPHA =2, C1=0.1 and H=1.0 The models parameters are included in the metadata of the .hdf5 : - alpha : degree of multifractality - C1 : degree of intermittency - H : degree of smoothness - radius : the preferred radius for 3D-representation - SEED : the identifier of the random seed The radius in not a parameter of the model. Still the choice of a particular radius can have a major impact on the visual output. If the radius is large compared to the topographic fluctuations, the body will tend to be spherical and close to a typical planetary shape. In the opposite, the body will have a more complex shape and potential resemblance with non-spherical small bodies. Depending on the the choice of H and C1, values for radius lead to more or less consistent shape. Thus we suggest in each case a preferred radius to be combined with the provided topography. Given the chosen range of H and C1 defined above, we provide 3x3=9 hdf5 topographic maps for each of the the six random seeds. 2) hdf5 files containing texture map to be applied on the topography. As our statistical model mainly consists in a control of roughness at different scales and location, the main goal of the texture map is to be visually significant in terms of roughness, reflecting the juxtaposition of rough and smooth places. We make use of the classic method of Hill-shading that consists in computing the scalar product between local slopes and a constant light direction. Given the spherical geometry, only a portion of the synthetic body can be clearly visible under a specific light direction. For each topographic map we provide hill-shade textures in an arbitrarily chosen light direction . For H=1, the colormap is as a shade of gray whereas for H<1, it tends to reproduce the color of an earth-like planet. Additionally, we provide a texture colormap without hill-shading in each case. As a result, there are two distinct texture maps for each field with the following nomenclature : Texture nomenclature : S{seed id}_A{value of alpha x10}_C{value of C1 x100}_H{value of H x10}_LAT{latitude sampling_LON{longitude sampling}{"COLO" or "FLAT"}["SHADE" or "FLAT"}.hdf5 The texture map is inside the .hdf5 file in the dataset "/data". Parameters are recorded in the metadata. The latitude sampling is inside the .hdf5 file in the dataset "/lat". The longitude sampling is inside the .hdf5 file in the dataset "/long". - Example : S01_A20_C00_H04_LAT_5000_LON10000COLOSHAD.hdf5 : 5000x10000x3 uint8 texture image with hillshading and earthlike colormap. - Example : S01_A20_C00_H04_LAT_5000_LON10000COLOFLAT.hdf5 : 5000x10000x3 uint8 texture image without hillshading and earthlike colormap. - Example : S01_A20_C00_H10_LAT_5000_LON10000GRAYSHAD.hdf5 : 5000x10000x3 uint8 texture image with hillshading and shade-of-gray colormap The models parameters are included in the metadata of the .hdf5 : - alpha : degree of multifractality - C1 : degree of intermittency - H : degree of smoothness Conclusion : the folder is composed of topographic maps and texture maps. Ideally, the users should be able to switch between random seeds and values of H and C1 references : - Landais, F., Schmidt, F., and Lovejoy, S, (2018) Topography of exoplanets, MNRAS - Lavallée, D., Lovejoy, S., Schertzer, D., & Ladoy, P. (1993). Nonlinear variability and landscape topography: analysis and simulation. Fractals in geography, edited by L. De Cola and N. Lam, Prentice-Hall, New Jersey, 158-192.