This vignette walks through the GLASS data lifecycle covered by the
package: registry lookups, tile mapping, DOY folders, downloading and
post-processing. Dataset-bound chunks run offline; anything that touches
the network is shown with eval = FALSE so the vignette
builds without connectivity.
The product registry
The registry has one row per archive variant (product x source x resolution) observed under https://glass.hku.hk/archive/:
glass_registry(verified_only = TRUE)[, c("variant_id", "res", "cadence_days",
"observed_years", "url_root")]
#> variant_id res
#> 1 AGB_0.01D_V02 V02
#> 2 AGB_0.05D <NA>
#> 3 AGB_0.05D_old <NA>
#> 4 AGB_1KM_V01 V01
#> 5 Albedo_ABI_0_05D 0.05D
#> 6 Albedo_ABI_0_5D 0.5D
#> 7 Albedo_ABI_500M 500M
#> 8 Albedo_ABI_landcover_climatology landcover_climatology
#> 9 Albedo_AVHRR_0_5D 0.5D
#> 10 Albedo_MIX_0_05D 0.05D
#> 11 Albedo_MIX_0_5D 0.5D
#> 12 Albedo_MODIS_0_5D 0.5D
#> 13 Albedo_MODIS_250M 250M
#> 14 Albedo_MODIS_500M 500M
#> 15 AWGF_LST_ABI_2km 2km
#> 16 AWGF_LST_ABI_CMG_002deg CMG_002deg
#> 17 AWGF_LST_ABI_CMG_005deg CMG_005deg
#> 18 AWGF_LST_GHA-LST <NA>
#> 19 BBE_AVHRR_0_05D 0.05D
#> 20 BBE_AVHRR_0_1D 0.1D
#> 21 BBE_AVHRR_0_5D 0.5D
#> 22 BBE_MODIS_0_05D 0.05D
#> 23 BBE_MODIS_0_5D 0.5D
#> 24 BBE_MODIS_1KM 1KM
#> 25 BBE_MODIS_500M 500M
#> 26 Crops_PADDYCALENDAR <NA>
#> 27 Crops_PADDYINTENSITY <NA>
#> 28 Crops_PADDYINTERCROPPING <NA>
#> 29 DSR_AVHRR_0_05D 0.05D
#> 30 DSR_MODIS_0_05D 0.05D
#> 31 DSR_MODIS_0_5D 0.5D
#> 32 DSR_MODIS_Topo <NA>
#> 33 EDD_MODIS_1KM 1KM
#> 34 ET_AVHRR_0_05D 0.05D
#> 35 ET_AVHRR_0_5D 0.5D
#> 36 ET_MODIS_0_05D 0.05D
#> 37 ET_MODIS_0_5D 0.5D
#> 38 ET_MODIS_1KM 1KM
#> 39 EVI_MODIS_0_05 0.05
#> 40 EVI_MODIS_0_1 0.1
#> 41 EVI_MODIS_0_25 0.25
#> 42 EVI_MODIS_250M 250M
#> 43 FAPAR_AVHRR_0_05D 0.05D
#> 44 FAPAR_HR_FAPAR_V01 V01
#> 45 FAPAR_MODIS_0_05D 0.05D
#> 46 FAPAR_MODIS_0_1D 0.1D
#> 47 FAPAR_MODIS_0_25D 0.25D
#> 48 FAPAR_MODIS_0_5D 0.5D
#> 49 FAPAR_MODIS_250M 250M
#> 50 FAPAR_MODIS_500M 500M
#> 51 FFC_MODIS_250M 250M
#> 52 FVC_AVHRR_0_05D 0.05D
#> 53 FVC_AVHRR_0_5D 0.5D
#> 54 FVC_AVHRR_0_5D_netCDF 0.5D_netCDF
#> 55 FVC_MODIS_0_05D 0.05D
#> 56 FVC_MODIS_0_5D 0.5D
#> 57 FVC_MODIS_0_5D_netCDF 0.5D_netCDF
#> 58 FVC_MODIS_500M 500M
#> 59 GPP_AVHRR_0_05D 0.05D
#> 60 GPP_AVHRR_0_5D 0.5D
#> 61 GPP_MODIS_500M 500M
#> 62 KGClim_KGClim_V1_future_rcp2_6_2030s rcp2_6_2030s
#> 63 KGClim_KGClim_V1_future_rcp2_6_2050s rcp2_6_2050s
#> 64 KGClim_KGClim_V1_future_rcp2_6_2070s rcp2_6_2070s
#> 65 KGClim_KGClim_V1_future_rcp2_6_2080s rcp2_6_2080s
#> 66 KGClim_KGClim_V1_future_rcp4_5_2030s rcp4_5_2030s
#> 67 KGClim_KGClim_V1_future_rcp4_5_2050s rcp4_5_2050s
#> 68 KGClim_KGClim_V1_future_rcp4_5_2070s rcp4_5_2070s
#> 69 KGClim_KGClim_V1_future_rcp4_5_2080s rcp4_5_2080s
#> 70 KGClim_KGClim_V1_future_rcp6_0_2030s rcp6_0_2030s
#> 71 KGClim_KGClim_V1_future_rcp6_0_2050s rcp6_0_2050s
#> 72 KGClim_KGClim_V1_future_rcp6_0_2070s rcp6_0_2070s
#> 73 KGClim_KGClim_V1_future_rcp6_0_2080s rcp6_0_2080s
#> 74 KGClim_KGClim_V1_future_rcp8_5_2030s rcp8_5_2030s
#> 75 KGClim_KGClim_V1_future_rcp8_5_2050s rcp8_5_2050s
#> 76 KGClim_KGClim_V1_future_rcp8_5_2070s rcp8_5_2070s
#> 77 KGClim_KGClim_V1_future_rcp8_5_2080s rcp8_5_2080s
#> 78 KGClim_KGClim_V1_future_model_rcp2_6_2030s_model rcp2_6_2030s_model
#> 79 KGClim_KGClim_V1_future_model_rcp2_6_2050s_model rcp2_6_2050s_model
#> 80 KGClim_KGClim_V1_future_model_rcp2_6_2070s_model rcp2_6_2070s_model
#> 81 KGClim_KGClim_V1_future_model_rcp2_6_2080s_model rcp2_6_2080s_model
#> 82 KGClim_KGClim_V1_future_model_rcp4_5_2030s_model rcp4_5_2030s_model
#> 83 KGClim_KGClim_V1_future_model_rcp4_5_2050s_model rcp4_5_2050s_model
#> 84 KGClim_KGClim_V1_future_model_rcp4_5_2070s_model rcp4_5_2070s_model
#> 85 KGClim_KGClim_V1_future_model_rcp4_5_2080s_model rcp4_5_2080s_model
#> 86 KGClim_KGClim_V1_future_model_rcp6_0_2030s_model rcp6_0_2030s_model
#> 87 KGClim_KGClim_V1_future_model_rcp6_0_2050s_model rcp6_0_2050s_model
#> 88 KGClim_KGClim_V1_future_model_rcp6_0_2070s_model rcp6_0_2070s_model
#> 89 KGClim_KGClim_V1_future_model_rcp6_0_2080s_model rcp6_0_2080s_model
#> 90 KGClim_KGClim_V1_future_model_rcp8_5_2030s_model rcp8_5_2030s_model
#> 91 KGClim_KGClim_V1_future_model_rcp8_5_2050s_model rcp8_5_2050s_model
#> 92 KGClim_KGClim_V1_future_model_rcp8_5_2070s_model rcp8_5_2070s_model
#> 93 KGClim_KGClim_V1_future_model_rcp8_5_2080s_model rcp8_5_2080s_model
#> 94 KGClim_KGClim_V1_historical_1979_2008 1979_2008
#> 95 KGClim_KGClim_V1_historical_1980_2009 1980_2009
#> 96 KGClim_KGClim_V1_historical_1981_2010 1981_2010
#> 97 KGClim_KGClim_V1_historical_1982_2011 1982_2011
#> 98 KGClim_KGClim_V1_historical_1983_2012 1983_2012
#> 99 KGClim_KGClim_V1_historical_1984_2013 1984_2013
#> 100 LAI_AVHRR <NA>
#> 101 LAI_HR_LAI_V01 V01
#> 102 LAI_MODIS_0_05D 0.05D
#> 103 LAI_MODIS_0_1D 0.1D
#> 104 LAI_MODIS_0_25D 0.25D
#> 105 LAI_MODIS_0_5D 0.5D
#> 106 LAI_MODIS_250M 250M
#> 107 LAI_MODIS_500M 500M
#> 108 LST_AVHRR_0_05D 0.05D
#> 109 LST_AVHRR_05D 05D
#> 110 LST_AVHRR_Daily-ODC Daily-ODC
#> 111 LST_MODIS_Daily Daily
#> 112 LST_MODIS_Ins Ins
#> 113 LWRT_AVHRR <NA>
#> 115 LWRT_MODIS_InS_0_5D InS_0.5D
#> 116 NDVI_MODIS_0_05 0.05
#> 117 NDVI_MODIS_0_1 0.1
#> 118 NDVI_MODIS_0_25 0.25
#> 119 NDVI_MODIS_250M 250M
#> 120 NPP_AVHRR_0_05D 0.05D
#> 121 NPP_AVHRR_0_5D 0.5D
#> 122 NPP_MODIS_500M 500M
#> 123 PAR_MODIS_0_05D 0.05D
#> 124 PAR_MODIS_0_5D 0.5D
#> 125 RN_AVHRR <NA>
#> 126 RN_MODIS <NA>
#> 128 SM_AVHRR <NA>
#> 129 SM_MODIS <NA>
#> 130 SRF_MODIS_1KM 1KM
#> 131 Ta_MODIS <NA>
#> 132 TPSCE_AVHRR <NA>
#> 133 Tsa_MODIS <NA>
#> cadence_days observed_years
#> 1 NA <NA>
#> 2 NA <NA>
#> 3 NA <NA>
#> 4 NA <NA>
#> 5 NA <NA>
#> 6 NA <NA>
#> 7 NA <NA>
#> 8 NA <NA>
#> 9 NA 1981-2023
#> 10 NA 1981-2024
#> 11 NA 1981-2021
#> 12 NA 2000-2023
#> 13 4 2000-2024
#> 14 4 2000-2024
#> 15 1 2017-2021
#> 16 1 2017-2021
#> 17 1 2017-2021
#> 18 NA 2011-2025
#> 19 NA 1981-2022
#> 20 1 1980-2020
#> 21 NA 1981-2022
#> 22 NA 2000-2022
#> 23 NA 2000-2022
#> 24 1 2000-2022
#> 25 1 2018-2022
#> 26 NA <NA>
#> 27 NA <NA>
#> 28 NA <NA>
#> 29 NA 1981-2018
#> 30 NA 2000-2025
#> 31 NA 2000-2024
#> 32 NA 2003-2024
#> 33 1 2005-2022
#> 34 NA 1981-2022
#> 35 NA 1981-2022
#> 36 NA 2000-2024
#> 37 NA 2000-2021
#> 38 8 2000-2024
#> 39 NA 2000-2025
#> 40 NA 2000-2021
#> 41 NA 2000-2021
#> 42 8 2000-2025
#> 43 NA 1982-2018
#> 44 NA <NA>
#> 45 NA 2000-2025
#> 46 NA 2000-2025
#> 47 NA 2000-2025
#> 48 NA 2000-2025
#> 49 8 2000-2025
#> 50 8 2000-2025
#> 51 8 2000-2024
#> 52 NA 1981-2020
#> 53 NA 1981-2020
#> 54 NA 1982-2018
#> 55 NA 2000-2024
#> 56 NA 2000-2024
#> 57 NA 2000-2019
#> 58 8 2000-2024
#> 59 NA 1981-2018
#> 60 NA 1982-2018
#> 61 8 2000-2025
#> 62 NA <NA>
#> 63 NA <NA>
#> 64 NA <NA>
#> 65 NA <NA>
#> 66 NA <NA>
#> 67 NA <NA>
#> 68 NA <NA>
#> 69 NA <NA>
#> 70 NA <NA>
#> 71 NA <NA>
#> 72 NA <NA>
#> 73 NA <NA>
#> 74 NA <NA>
#> 75 NA <NA>
#> 76 NA <NA>
#> 77 NA <NA>
#> 78 NA <NA>
#> 79 NA <NA>
#> 80 NA <NA>
#> 81 NA <NA>
#> 82 NA <NA>
#> 83 NA <NA>
#> 84 NA <NA>
#> 85 NA <NA>
#> 86 NA <NA>
#> 87 NA <NA>
#> 88 NA <NA>
#> 89 NA <NA>
#> 90 NA <NA>
#> 91 NA <NA>
#> 92 NA <NA>
#> 93 NA <NA>
#> 94 NA <NA>
#> 95 NA <NA>
#> 96 NA <NA>
#> 97 NA <NA>
#> 98 NA <NA>
#> 99 NA <NA>
#> 100 NA 1981-2018
#> 101 NA <NA>
#> 102 NA 2000-2025
#> 103 NA 2000-2025
#> 104 NA 2000-2025
#> 105 NA 2000-2025
#> 106 8 2000-2025
#> 107 8 2000-2025
#> 108 NA 1982-2024
#> 109 NA 1981-2000
#> 110 NA 1981-2000
#> 111 1 2000-2020
#> 112 1 2002-2020
#> 113 NA 1981-2021
#> 115 1 2002-2018
#> 116 NA 2000-2025
#> 117 NA 2000-2021
#> 118 NA 2000-2021
#> 119 8 2000-2025
#> 120 NA 1981-2018
#> 121 NA 1982-2018
#> 122 8 2000-2025
#> 123 NA 2000-2025
#> 124 NA 2000-2024
#> 125 NA 1981-2018
#> 126 NA 2000-2024
#> 128 NA 1982-2021
#> 129 1 2000-2020
#> 130 1 2000-2023
#> 131 1 2000-2020
#> 132 NA 1981-2016
#> 133 1 2000-2020
#> url_root
#> 1 https://glass.hku.hk/archive/AGB/0.01D/V02/
#> 2 https://glass.hku.hk/archive/AGB/0.05D/
#> 3 https://glass.hku.hk/archive/AGB/0.05D_old/
#> 4 https://glass.hku.hk/archive/AGB/1KM/V01/
#> 5 https://glass.hku.hk/archive/Albedo/ABI/0.05D/
#> 6 https://glass.hku.hk/archive/Albedo/ABI/0.5D/
#> 7 https://glass.hku.hk/archive/Albedo/ABI/500M/
#> 8 https://glass.hku.hk/archive/Albedo/ABI/landcover_climatology/
#> 9 https://glass.hku.hk/archive/Albedo/AVHRR/0.5D/
#> 10 https://glass.hku.hk/archive/Albedo/MIX/0.05D/
#> 11 https://glass.hku.hk/archive/Albedo/MIX/0.5D/
#> 12 https://glass.hku.hk/archive/Albedo/MODIS/0.5D/
#> 13 https://glass.hku.hk/archive/Albedo/MODIS/250M/
#> 14 https://glass.hku.hk/archive/Albedo/MODIS/500M/
#> 15 https://glass.hku.hk/archive/AWGF_LST/ABI/2km/
#> 16 https://glass.hku.hk/archive/AWGF_LST/ABI/CMG_002deg/
#> 17 https://glass.hku.hk/archive/AWGF_LST/ABI/CMG_005deg/
#> 18 https://glass.hku.hk/archive/AWGF_LST/GHA-LST/
#> 19 https://glass.hku.hk/archive/BBE/AVHRR/0.05D/
#> 20 https://glass.hku.hk/archive/BBE/AVHRR/0.1D/
#> 21 https://glass.hku.hk/archive/BBE/AVHRR/0.5D/
#> 22 https://glass.hku.hk/archive/BBE/MODIS/0.05D/
#> 23 https://glass.hku.hk/archive/BBE/MODIS/0.5D/
#> 24 https://glass.hku.hk/archive/BBE/MODIS/1KM/
#> 25 https://glass.hku.hk/archive/BBE/MODIS/500M/
#> 26 https://glass.hku.hk/archive/Crops/PADDYCALENDAR/
#> 27 https://glass.hku.hk/archive/Crops/PADDYINTENSITY/
#> 28 https://glass.hku.hk/archive/Crops/PADDYINTERCROPPING/
#> 29 https://glass.hku.hk/archive/DSR/AVHRR/0.05D/
#> 30 https://glass.hku.hk/archive/DSR/MODIS/0.05D/
#> 31 https://glass.hku.hk/archive/DSR/MODIS/0.5D/
#> 32 https://glass.hku.hk/archive/DSR/MODIS_Topo/
#> 33 https://glass.hku.hk/archive/EDD/MODIS/1KM/
#> 34 https://glass.hku.hk/archive/ET/AVHRR/0.05D/
#> 35 https://glass.hku.hk/archive/ET/AVHRR/0.5D/
#> 36 https://glass.hku.hk/archive/ET/MODIS/0.05D/
#> 37 https://glass.hku.hk/archive/ET/MODIS/0.5D/
#> 38 https://glass.hku.hk/archive/ET/MODIS/1KM/
#> 39 https://glass.hku.hk/archive/EVI/MODIS/0.05/
#> 40 https://glass.hku.hk/archive/EVI/MODIS/0.1/
#> 41 https://glass.hku.hk/archive/EVI/MODIS/0.25/
#> 42 https://glass.hku.hk/archive/EVI/MODIS/250M/
#> 43 https://glass.hku.hk/archive/FAPAR/AVHRR/0.05D/
#> 44 https://glass.hku.hk/archive/FAPAR/HR_FAPAR/V01/
#> 45 https://glass.hku.hk/archive/FAPAR/MODIS/0.05D/
#> 46 https://glass.hku.hk/archive/FAPAR/MODIS/0.1D/
#> 47 https://glass.hku.hk/archive/FAPAR/MODIS/0.25D/
#> 48 https://glass.hku.hk/archive/FAPAR/MODIS/0.5D/
#> 49 https://glass.hku.hk/archive/FAPAR/MODIS/250M/
#> 50 https://glass.hku.hk/archive/FAPAR/MODIS/500M/
#> 51 https://glass.hku.hk/archive/FFC/MODIS/250M/
#> 52 https://glass.hku.hk/archive/FVC/AVHRR/0.05D/
#> 53 https://glass.hku.hk/archive/FVC/AVHRR/0.5D/
#> 54 https://glass.hku.hk/archive/FVC/AVHRR/0.5D_netCDF/
#> 55 https://glass.hku.hk/archive/FVC/MODIS/0.05D/
#> 56 https://glass.hku.hk/archive/FVC/MODIS/0.5D/
#> 57 https://glass.hku.hk/archive/FVC/MODIS/0.5D_netCDF/
#> 58 https://glass.hku.hk/archive/FVC/MODIS/500M/
#> 59 https://glass.hku.hk/archive/GPP/AVHRR/0.05D/
#> 60 https://glass.hku.hk/archive/GPP/AVHRR/0.5D/
#> 61 https://glass.hku.hk/archive/GPP/MODIS/500M/
#> 62 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp2_6_2030s/
#> 63 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp2_6_2050s/
#> 64 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp2_6_2070s/
#> 65 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp2_6_2080s/
#> 66 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp4_5_2030s/
#> 67 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp4_5_2050s/
#> 68 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp4_5_2070s/
#> 69 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp4_5_2080s/
#> 70 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp6_0_2030s/
#> 71 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp6_0_2050s/
#> 72 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp6_0_2070s/
#> 73 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp6_0_2080s/
#> 74 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp8_5_2030s/
#> 75 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp8_5_2050s/
#> 76 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp8_5_2070s/
#> 77 https://glass.hku.hk/archive/KGClim/KGClim_V1_future/rcp8_5_2080s/
#> 78 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp2_6_2030s_model/
#> 79 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp2_6_2050s_model/
#> 80 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp2_6_2070s_model/
#> 81 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp2_6_2080s_model/
#> 82 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp4_5_2030s_model/
#> 83 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp4_5_2050s_model/
#> 84 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp4_5_2070s_model/
#> 85 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp4_5_2080s_model/
#> 86 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp6_0_2030s_model/
#> 87 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp6_0_2050s_model/
#> 88 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp6_0_2070s_model/
#> 89 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp6_0_2080s_model/
#> 90 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp8_5_2030s_model/
#> 91 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp8_5_2050s_model/
#> 92 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp8_5_2070s_model/
#> 93 https://glass.hku.hk/archive/KGClim/KGClim_V1_future_model/rcp8_5_2080s_model/
#> 94 https://glass.hku.hk/archive/KGClim/KGClim_V1_historical/1979_2008/
#> 95 https://glass.hku.hk/archive/KGClim/KGClim_V1_historical/1980_2009/
#> 96 https://glass.hku.hk/archive/KGClim/KGClim_V1_historical/1981_2010/
#> 97 https://glass.hku.hk/archive/KGClim/KGClim_V1_historical/1982_2011/
#> 98 https://glass.hku.hk/archive/KGClim/KGClim_V1_historical/1983_2012/
#> 99 https://glass.hku.hk/archive/KGClim/KGClim_V1_historical/1984_2013/
#> 100 https://glass.hku.hk/archive/LAI/AVHRR/
#> 101 https://glass.hku.hk/archive/LAI/HR_LAI/V01/
#> 102 https://glass.hku.hk/archive/LAI/MODIS/0.05D/
#> 103 https://glass.hku.hk/archive/LAI/MODIS/0.1D/
#> 104 https://glass.hku.hk/archive/LAI/MODIS/0.25D/
#> 105 https://glass.hku.hk/archive/LAI/MODIS/0.5D/
#> 106 https://glass.hku.hk/archive/LAI/MODIS/250M/
#> 107 https://glass.hku.hk/archive/LAI/MODIS/500M/
#> 108 https://glass.hku.hk/archive/LST/AVHRR/0.05D/
#> 109 https://glass.hku.hk/archive/LST/AVHRR/05D/
#> 110 https://glass.hku.hk/archive/LST/AVHRR/Daily-ODC/
#> 111 https://glass.hku.hk/archive/LST/MODIS/Daily/1KM/
#> 112 https://glass.hku.hk/archive/LST/MODIS/Ins/
#> 113 https://glass.hku.hk/archive/LWRT/AVHRR/
#> 115 https://glass.hku.hk/archive/LWRT/MODIS/InS_0.5D/
#> 116 https://glass.hku.hk/archive/NDVI/MODIS/0.05/
#> 117 https://glass.hku.hk/archive/NDVI/MODIS/0.1/
#> 118 https://glass.hku.hk/archive/NDVI/MODIS/0.25/
#> 119 https://glass.hku.hk/archive/NDVI/MODIS/250M/
#> 120 https://glass.hku.hk/archive/NPP/AVHRR/0.05D/
#> 121 https://glass.hku.hk/archive/NPP/AVHRR/0.5D/
#> 122 https://glass.hku.hk/archive/NPP/MODIS/500M/
#> 123 https://glass.hku.hk/archive/PAR/MODIS/0.05D/
#> 124 https://glass.hku.hk/archive/PAR/MODIS/0.5D/
#> 125 https://glass.hku.hk/archive/RN/AVHRR/
#> 126 https://glass.hku.hk/archive/RN/MODIS/
#> 128 https://glass.hku.hk/archive/SM/AVHRR/
#> 129 https://glass.hku.hk/archive/SM/MODIS/
#> 130 https://glass.hku.hk/archive/SRF/MODIS/1KM/
#> 131 https://glass.hku.hk/archive/Ta/MODIS/
#> 132 https://glass.hku.hk/archive/TPSCE/AVHRR/
#> 133 https://glass.hku.hk/archive/Tsa/MODIS/Variants with verified = TRUE were checked against real
granules: file naming fragments (code,
version, layer), year coverage, and band
metadata (fill_value, scale_factor,
valid_min/valid_max) all come from that check and are
consumed by glass_read()/glass_process().
From region of interest to tiles
Tiled GLASS products reuse the MODIS sinusoidal
h<v> grid. Rebuild the exact tile polygons and see
which ones your study area needs:
# 一个 2-3 km 缓冲的点(上海人民广场周边)
roi <- sf::st_buffer(
sf::st_sfc(sf::st_point(c(121.47, 31.23)), crs = 4326),
3000
)
tiles <- glass_tiles_for_sf(roi)
tiles[, c("h", "v", "lon_min", "lon_max", "lat_min", "lat_max", "valid")]
#> Simple feature collection with 1 feature and 7 fields
#> Geometry type: POLYGON
#> Dimension: XY
#> Bounding box: xmin: 115.4701 ymin: 30 xmax: 143.5948 ymax: 40
#> Geodetic CRS: WGS 84
#> h v lon_min lon_max lat_min lat_max valid geometry
#> 1 28 5 115.4701 143.5948 30 40 TRUE POLYGON ((130.5407 40, 143....For straight bounding boxes there is
glass_tiles_for_bbox(), and passing the resulting table
directly to glass_fetch() is allowed (it understands data
frames with h/v columns).
Date range to composite folders
The archive stores one folder per composite start day-of-year:
glass_doys("LAI_MODIS_250M", from = "2018-08-01", to = "2018-08-31")
#> # A tibble: 5 × 4
#> year doy date folder
#> <int> <int> <date> <chr>
#> 1 2018 209 2018-07-28 209
#> 2 2018 217 2018-08-05 217
#> 3 2018 225 2018-08-13 225
#> 4 2018 233 2018-08-21 233
#> 5 2018 241 2018-08-29 241mode = "span" (default) keeps composites partially
overlapping the range; mode = "start" keeps only those
starting inside it.
Finding and downloading files
glass_list_files() reads one composite folder’s listing;
glass_fetch() loops it over the DOY table and downloads
with resume/verification:
files <- glass_fetch(
"LAI_MODIS_250M",
from = "2018-08-01", to = "2018-12-31",
roi = roi,
out_dir = "data/glass/lai"
)
# 用 dry_run = TRUE 先看清单,不下载The download engine compares sizes with the server, resumes
.part files via HTTP Range, and writes
glass_manifest.csv into out_dir, so an
interrupted run continues where it stopped.
Post-processing
glass_process() is the parameterised pipeline: cleanup,
mosaic, reproject, mask, optional temporal collapse:
mean_lai <- glass_process(
files,
roi = roi,
product = "LAI_MODIS_250M",
method = "cubic",
fun = "mean",
outfile = "glass_lai_mean.tif"
)Band cleanup comes from the registry: the raw fill (e.g. 255) maps to
NA after scaling, and the valid scaled range is excluded
from analysis. For an already-read SpatRaster,
glass_read() with no product is a no-op except
for explicit fill/valid_range arguments.
Interactive UI
Draw the ROI on a map, pick a verified variant, preview the manifest and download — the same package functions underneath. The output folder can be chosen through the built-in, in-page directory browser (or typed directly) and a progress bar follows each file during the batch download.