Coverage for enpt/processors/radiometric_transform/radiometric_transform.py: 100%

1# -*- coding: utf-8 -*- 

2 

3# EnPT, EnMAP Processing Tool - A Python package for pre-processing of EnMAP Level-1B data 

4# 

5# Copyright (C) 2018-2024 Karl Segl (GFZ Potsdam, segl@gfz-potsdam.de), Daniel Scheffler 

6# (GFZ Potsdam, danschef@gfz-potsdam.de), Niklas Bohn (GFZ Potsdam, nbohn@gfz-potsdam.de), 

7# Stéphane Guillaso (GFZ Potsdam, stephane.guillaso@gfz-potsdam.de) 

8# 

9# This software was developed within the context of the EnMAP project supported 

10# by the DLR Space Administration with funds of the German Federal Ministry of 

11# Economic Affairs and Energy (on the basis of a decision by the German Bundestag: 

12# 50 EE 1529) and contributions from DLR, GFZ and OHB System AG. 

13# 

14# This program is free software: you can redistribute it and/or modify it under 

15# the terms of the GNU General Public License as published by the Free Software 

16# Foundation, either version 3 of the License, or (at your option) any later 

17# version. Please note the following exception: `EnPT` depends on tqdm, which 

18# is distributed under the Mozilla Public Licence (MPL) v2.0 except for the files 

19# "tqdm/_tqdm.py", "setup.py", "README.rst", "MANIFEST.in" and ".gitignore". 

20# Details can be found here: https://github.com/tqdm/tqdm/blob/master/LICENCE. 

21# 

22# This program is distributed in the hope that it will be useful, but WITHOUT 

23# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 

24# FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more 

25# details. 

26# 

27# You should have received a copy of the GNU Lesser General Public License along 

28# with this program. If not, see <https://www.gnu.org/licenses/>. 

29 

30"""EnPT 'radiometric transform' module. 

31 

32Contained Transformations: 

33 - TOA radiance to TOA reflectance 

34""" 

35 

36import math 

37import numpy as np 

38 

39from ...model.images import EnMAPL1Product_SensorGeo, EnMAP_Detector_SensorGeo # noqa F401 # flake8 issue 

40from ...options.config import EnPTConfig 

41 

42__author__ = 'Daniel Scheffler' 

43 

44 

45class Radiometric_Transformer(object): 

46 """Class for performing all kinds of radiometric transformations of EnMAP images.""" 

47 

48 def __init__(self, config: EnPTConfig = None): 

49 """Create an instance of Radiometric_Transformer. 

50 

51 :param config: EnPT configuration object 

52 """ 

53 self.cfg = config 

54 self.solarIrr = config.path_solar_irr # path of model for solar irradiance 

55 self.earthSunDist = config.path_earthSunDist # path of model for earth sun distance 

56 

57 def transform_TOARad2TOARef(self, enmap_ImageL1: EnMAPL1Product_SensorGeo): 

58 """Transform top-of-atmosphere radiance to top-of-atmosphere reflectance (16-bit signed-integer). 

59 

60 NOTE: The following formula is used: 

61 toaRef = (scale_factor * math.pi * toaRad * earthSunDist**2) / 

62 (solIrr * math.cos(zenithAngleDeg)) 

63 

64 :param enmap_ImageL1: instance of the class 'EnMAPL1Product_ImGeo' 

65 :return: 

66 """ 

67 for detectorName in enmap_ImageL1.detector_attrNames: 

68 detector: EnMAP_Detector_SensorGeo = getattr(enmap_ImageL1, detectorName) 

69 

70 enmap_ImageL1.logger.info('Converting TOA radiance to TOA reflectance for %s detector...' 

71 % detector.detector_name) 

72 

73 # compute TOA reflectance 

74 constant = \ 

75 self.cfg.scale_factor_toa_ref * math.pi * enmap_ImageL1.meta.earthSunDist ** 2 / \ 

76 (math.cos(math.radians(enmap_ImageL1.meta.geom_sun_zenith))) 

77 solIrr = detector.detector_meta.solar_irrad.reshape(1, 1, detector.data.bands) 

78 toaRef = (constant * detector.data[:] / solIrr).astype(np.int16) 

79 

80 # update EnMAP image 

81 detector.data = toaRef 

82 detector.detector_meta.unit = '0-%d' % self.cfg.scale_factor_toa_ref 

83 detector.detector_meta.unitcode = 'TOARef' 

84 

85 return enmap_ImageL1