100 likes | 205 Views
How to get the job done without a supercomputer. DEM generation using Mars Express data. By Jasper Van doninck. Used data. 771601 samples produced by image matching Cartesian geocentric coordinates: X, Y, Z Standard deviations σ X , σ Y , σ Z. Data Preparation.
E N D
How to get the job done without a supercomputer DEM generation using Mars Express data By Jasper Van doninck
Used data • 771601 samples produced by image matching • Cartesian geocentric coordinates: X, Y, Z • Standard deviations σX, σY, σZ
Data Preparation • Coordinate transformation: 10 iterations
Data Preparation (2) • Mars Reference spheroid: IAU/IAG 2000 a=3396190 m b=3376200 m e=(a2-b2)/a2 • Study area: λ≈48˚50’ W - 47˚35’ W ψ≈0˚15’ S - 13˚37’ N ≈ 74 km x 822 km
Data Preparation (3) -Partitioning of dataset into 8 tab delimited .txt files λ ψ H (σH) 7 files of 100 000 records 1 file of 71 601 records -Load data in Acces – import as XY-data in ArcGIS, convert to shapefiles
Kriging • Create Prediction Map + Prediction Standard Error Map for every subset • Export prediction maps + standard error maps to raster • 1arcmin grid, block interpolation 12*12 cels (≈82m)
Final Map Generation -Combine subsets to 1 map: Weighted average Vr,c= (Σ Vr,c,i/Er,c,i)/(Σ 1/Er,c,i) Vr,c = Predicted height of cel r,c Vr,c,i = Predicted height of cel in subset i Er,c,i = Prediction standard error in subset i