Satellite imagery for CWRS from Irish perspective Speaker: Aleksandra Kocon Author: Aleksandra Kocon aleksandra@icon.ie
Introduction Long acquisition windows / windows fitting with crop cycle problem Main problem: CLOUDS Partial zone acquisitions (13 zones in 2018 VHR1) Sometimes high failure rate for HR Limited Sentinel 2 availability
Ireland CWRS 2015 48 zones Zone size: 375 km² Total area: 18000 km² VHR2 75% of CWRS area Methods: (36) (36) (2) (36) (13) : 36 zones Winter HR VHR1 HRB1 VHR2 HR+1 12 zones Windows: (12) (12) (3) Winter HR VHR1 HR+1 Winter HR 11 weeks 20/12/2014 11/03/2015 (12) number of zones successfully acquired VHR1 12/03/2015 (17 zones) - 27/07, all captured by 21/04(3-6 weeks) 2/04/2015 (31 zones) HRB1 08/06/2015-20/07/2015* * - extended till 28/07/2015 (final window 7 weeks) VHR2 11 weeks 29/07/2015-15/10/2015 ; all captured by 13/10 HR+1 4 weeks window 17 zones 09/2015-10/2015 18 zones 10/2015-11/2015 1 zone 11/2015-12/2015 HR+1 01/07/2015-12/09/2015* *extended till 18/09/2015 (final window 6 weeks)
Ireland CWRS 2015 48 zones Scenes processed Zone size: 375 km² Total area: Number of 18000 Imagery km² type scenes HR_winter 46 VHR1 129 HRB1 2 VHR2 63 HR+1 16 RapidEye (HR 5m) 33 Sentinel1 (radar) 96 Methods: 36 zones 12 zones (36) (36) (2) (36) (13) Winter HR VHR1 HRB1 VHR2 HR+1 (12) (12) (3) Winter HR VHR1 HR+1 (12) number of zones successfully acquired First year of GREENING scheme Sentinel 2 not available that time Sentinel 1 available and used for crop check Additional imagery acquired (RAPID EYE and DEMOS) for parcels outside zone and greening crop check and catch crops Deimos (HR 22m) 1 LPIS QA 3 389
Ireland CWRS 2015 One of the problems back in 2015: patchy VHR1 acquisitions example of CAHI zone 2 2 North 26/03/2015 176 km², CC 9.3% 3a 3a Mid 08/04/2015 52 km², CC 0% 1 Southwest 14/03/2015 111 km², CC 4.7% 3b East 08/04/2015 36 km²,cc 0% 1 Image 1 - 'WorldView-2-data, European Space Imaging/DigitalGlobe, 2015, distributed by European Space Imaging Image 2 - GeoEye-1 data European Space Imaging/DigitalGlobe, 2015, distributed by European Space Imaging Image 3a, 3b- 'WorldView-3-data, European Space Imaging/DigitalGlobe, 2015, distributed by European Space Imaging' 3b
Ireland CWRS 2015 Issue addressed by the image provider and did not repeat for VHR2. Proposed alternative was to use two WORLDVIEW 03 images from 08/04/2015 (full coverage ) and low cloud cover %. 2 3a 1 3b 4 Before Image 1 - 'WorldView-2-data, European Space Imaging/DigitalGlobe, 2015, distributed by European Space Imaging After Image 2 - GeoEye-1 data European Space Imaging/DigitalGlobe, 2015, distributed by European Space Imaging Image 3a, 3b, 4- 'WorldView-3-data, European Space Imaging/DigitalGlobe, 2015, distributed by European Space Imaging'
Ireland CWRS 2016 48 zones Zone size: 294 km² Total area: 14100 km² VHR2 27 % of CWRS area Methods: 13 zones Windows: (13) (13) (13) (1) Winter HR VHR1 VHR2 HR+1 (35) (35) (35) 35 zones Winter HR VHR1 HR+1 HR+2 Winter HR 12 weeks 15/12/2015 15/03/2016 (12) number of zones successfully acquired VHR1 8 weeks 15/03/2016 15/05/2016 all captured by 13/05/2016 VHR2 10 weeks 15/06/2016-04/09/2016 all captured by 24/08/2016 HR+1 4 weeks (starting end of August) with few days extension HR+1 15/06/2016-13/07/2016* (none captured within initial 4 weeks window) *extended till 19/08/2016 (final window 8 weeks) HR+2 4 weeks (starting end of August) with few day extension (4)
Ireland CWRS 2016 48 zones Zone size: 294 km² Total area: 14100 km² Second year of GREENING scheme Sentinel 2 available and processed Sentinel 1 not used No additional imagery purchased Number of Imagery type scenes HR_winter 50 VHR1 87 VHR2 29 HR+1 36 HR+2 4 Sentinel2 23 LPIS QA 3 232
Ireland CWRS 2017 Adjusted with natural features (coastline), country border Overlap with CWRS zones from last two years removed Adjusted with OSI grid which is basic mapping unit for imagery input to Basic Payment System Neighbouring zones merged for easier image acquisition and processing Initial 48 zones Initial Final 4834 zones Final 34 zones
Ireland CWRS 2017 34 zones (equivalent of 48) Zone size: variable Total area: 12400 km² VHR2 44 % of CWRS area Methods: 13 zones Windows: (13) (13) (13) (2) Winter HR VHR1 VHR2 HR+1 (20) (21) (21) 21 zones Winter HR VHR1 HR+1 HR+2 Winter HR 11 weeks 21/12/2016 15/03/2017 VHR1 8-10 weeks 15/03/2017 15/05/2017 or 29/05/2017 all captured by 26/03/2017, apart 1 zone 25/05/2017 VHR2 8-10 weeks 15/06/2017-15/08/2017 or 29/08/2017; all captured by 18/06/2017 HR+1 4 weeks 22/08/2017 19/09/2017 (1) (12) number of zones successfully acquired HR+1 4 weeks 15/06/2017-13/07/2017 with 3 zones extended by 5 weeks till 21/08/2017 HR+2 4 weeks 22/08/2017 19/09/2017
Ireland CWRS 2017 34 zones (equivalent of 48) Zone size: variable Total area: 12400 km² Third year of GREENING scheme Sentinel 2 available and processed Sentinel 1 not used No additional imagery purchased Number of Imagery type scenes HR_winter 33 VHR1 72 VHR2 28 HR+1 23 HR+2 1 Sentinel2 25 LPISQA 3 173
June 2017 Sensor MODIS (Terra) Source: https://worldview.earthdata.nasa.gov/
July 2017 Sensor MODIS (Terra) Source: https://worldview.earthdata.nasa.gov/
August 2017 Sensor MODIS (Terra) Source: https://worldview.earthdata.nasa.gov/
Ireland CWRS 2018 34 zones (equivalent of 48) Zone size: variable Total area: 12800 km² VHR2 100 % of CWRS area Method: 34 zones VHR1 VHR2 Windows: VHR1 12 weeks 15/03/2017 15/06/2017 VHR2 9 weeks 21/06/2017-30/08/2017 + Sentinel 1 and Sentinel 2 Why HR is not acquired? Ideal window 15/05/-15/06 Ideal window 15/07/-15/08 VHR constellation (WV02, WV03, WV04, GE01 with Acomp) the most reliable. During 2015-2017 only one partial zone was delivered as panchromatic (WV1). With HR sometimes failure rate was high.
How imagery is being processed VHR bundle mode ordered (originally 16bit). Steps: 1) Orthocorrection (panchromatic, multispectral) 2) Pansharpening 3) Colour/contrast adjustment in ERDAS 4) Adjusted image is exported (LUT stretch) as 8 bit in.img format. 5) Then Global Mapper is used for cutting out black edges, creating mosaics for partial acquisitions. 6) Final image is pyramided to be used in BPS system and also final image is exported as.ecw to be used in MapInfo. Imagery type Bands HR FC VHR1 TC VHR2 TC, FC Sentinel 2 FC, TC since 2017 HR bundle or pansharpened mode, reduced to 8 bit after colour/contrast adjustment. Saved as ECW to be used in Mapinfo. Sentinel 2 R,G,B,IR bands are stitched, colours/contrast adjusted and processed to ECW. All checks for CWRS are visual and there is no visual difference between 8 bit and 16 bit in ERDAS. Size of the 8bit file is much smaller (50%).
How imagery is being used Winter HR winter activity (ploughing for winter crops, ploughing for spring crops) VHR1 boundary validation, crop check. Also for LPIS updates. VHR2 boundary validation for problematic parcels (when VHR1 not clear T4,T5), crop check. Also for LPIS updates. Other HR agriculture activity, crop check Sentinel 2 agriculture activity, crop check
Additional processing of shadowed areas Example for SWIN zone, GE01 13/05/2016 GeoEye-1 data European Space Imaging/DigitalGlobe, 2016, distributed by European Space Imaging
Winter HR, 2/01/2017 Spot7 VHR1, 25/05/2017 WV02 Left image - Spot 7 Airbus DS (2017) Right image- 'WorldView-2-data, European Space Imaging/DigitalGlobe, 2017, distributed by European Space Imaging
VHR1, 25/05/2018 WV02 VHR2, GE01 17/06/2017 Left image - 'WorldView-2-data, European Space Imaging/DigitalGlobe, 2017, distributed by European Space Imaging Right image - GeoEye-1 data European Space Imaging/DigitalGlobe, 2017, distributed by European Space Imaging
VHR2, GE01 17/06/2017 Sentinel 2, 17/07/2017 Left image - GeoEye-1 data European Space Imaging/DigitalGlobe, 2017, distributed by European Space Imaging Right image -
Low image usage % Selection of Herds 1. All schemes included in Risk Analysis 2. Risk based selections still apply, particularly for Pillar 2 schemes 3. Attempting to combine risk analysis selection and maximising use of RS for efficiency purposes 4. Imagery not used for CwRS used for LPIS update High cost of imagery one of the solution might be flexibility to revise the contract during CwRS. For example after VHR1 - if VHR1 is cloudless then possible change of VHR2 to HR.