Testing of Field- Map/TruPulse technology for measurement of forest parcels using JRC methodology Field-Map User Conference Krkonoše

Why to measure an agricultural parcels? The CAP, since the 2003 reform, aims to provide for a stable farmers income, decoupled from production, within a framework of sustainable development of the rural areas while respecting environmental and other societal needs. To distribute Community aid, the MS have to establish a Paying Agency to collect, control and reimburse all farmers applications through the IACS system with its geographical module LPIS. CAP … EU Common Agricultural Policy IACS … Integrated Administrational and Control System LPIS … Land Parcel Identification System source

How to measure an agricultural parcels? Article 34 of Commission Regulation (EC) No 1122/2009 requires that EU Member States use tools of a proven quality in order to measure agricultural parcels claimed for the Common Agricultural Policy area based subsidies. This requirement applies to the GNSS devices used by the Member States during their ON THE SPOT CONTROLS. In order to evaluate the reliability and accuracy of area measurement with GNSS receivers and because the assessment of GNSS point accuracy is not sufficient, the JRC elaborated a validation protocol for the area measurements based on the ISO 5275 norm. Following this protocol, a BUFFER TOLERANCE is determinated in the framework of AREA MEASUREMENT VALIDATION SCHEME. JRC … EU Joint Research Centre GNSS … Global Navigation Satellite System (GPS, Glonass, Galileo) source

JRC area measurement validation scheme Validation scheme step by step: 1. Design test site. 2. Mark the borders of polygons. 3. Get the reference areas/perimeters. 4. Schedule your measurements. 5. Collect data. 6. Statistical processing. 7. Derived the technical tolerance to be used. 8. Document all the process. HARDWARE+SOFTWARE+SETTINGS+METHOD source

Why/How to measure a forest parcels? Forest parcels eligible for area based CAP subsidies: first afforestation of non-agricultural land Natura 2000 payments forest-environment payments While measuring the forest be ready for: - no or weaker GNSS signal (forest canopy, valleys and ravines) - harsh measurement condition (obstacles, slope) - visibility limitation (dense under-storey) - no clear boundary identification + lower expectations (buffer tolerance 3 m forest parcels x 1,5 m agricultural parcels)

Field-Map/TruPulse technology Hardware components: TruPulse 360B laser rangefinder/inclinometer/compass Field computer Accessories (poles, reflectors, monopod, batteries etc.) Software: Field-Map Data Collector Field-Map custom application – Area Measurement

Field-Map/TruPulse validation Design the test site (= establish a set of test polygons)! Requirements: –Unambiguous borders (marking the boundary with wooden sticks with a density of at least 1 peg per 25 m). –At least 5 test polygons of different size (appr. 0,2-4 ha) and shapes (simple rectangular, prolongated, complex shape). Radlík test site (6 test polygons): - square 0.36 ha - long rectangular 0.69 ha - complex-shape polygon 5.57 ha - complex-shape polygon 2.40 ha - complex-shape polygon 1.76 ha - rectangular 1.52 ha

Field-Map/TruPulse validation Mark the borders of polygons!

Field-Map/TruPulse validation Total station Leica TRC 307 Get the reference areas and perimeters (RTK or surveying equipments) !

Field-Map/TruPulse validation Schedule your measurements! Requirements: –At least 8 series per polygon. –At least 4 repetitions per single series (changing clockwise and anti- clockwise direction). –Several equipments units. –Revisit time for the GPS satellite constellation to be appr. 12 hours. Field-Map/TruPulse test: - 9 series per each test polygon - 4 repetitions per single series (2 CW and 2ACW) - 3 teams and 3 sets of equipments - revisit time N/A

Collect data! 6 polygons x 9 series x 4 repetitions = 216 measured polygons 3 teams (2 persons per team)

Field-Map/TruPulse validation Statistical data processing! Requirements: –Detect outliers (Grubbs and Cochran tests). –Analyze impact of different factors (field, operator, set). –Check absence of bias (Students t-test). –Compute reproducibility standard deviation. –Compute reproducibility limit. –Derive technical tolerance to be used

Statistical data processing 1.Pre-processing: closing polygons using Bowditch transformation calculating areas and perimeters using Polyshape extension EDA - normality test (skewness&kurtosis, Shapiro-Wilk test) - outliers/stragglers identification (Cochran, Grubbs tests) - bias test (Student T test) 2.Buffer calculation - repeatability - variance - reproducibility variance - reproducibility limit 3.Reporting

The mean reproducibility limit (buffer) of the measurement (95% confidence level) of all parcels, expressed as a buffer width, was found to be 0,34 m. In conclusion, following the result, it is suggested to use a 0,50 m buffer tolerance to be applied to measurements made with Field-Map Data Collector (v. 10) including TruPulse 360B rangefinder (firmware A3,07-b3,37) using vertex method. We recommend also to systematically locate one vertex per field using a GNSS device in order to correctly geo reference each measurement done. Results are fully compliant with standard test EU Commission Joint Research Centre Validation result

Field-Map/TruPulse technology: 1.belongs to the best category of equipments for area measurement. 2.has the comparable area measurement precision inside the forest as hi-tech GPS receivers outside the forest. Conclusion

Lines-to-polygons transformation functions for line cleaning and polygon building wizard covering whole functionality Field-Map Data Collector – Polyshape wizard

Bowditch transformation transformation of traverse + related point layer 2 GPS points or closing traverse to the origin Field-Map Data Collector – Bowditch transformation

Line smoothing user controlled smoothness more natural-like boundaries Field-Map Data Collector – line smoothing

Background maps raster (i.e. aerial photo/satellite image) and vector formats on-screen info from linked database Field-Map Data Collector – active background maps

Thank you for your attention IFER – Institute of Forest Ecosystem Research Ltd. Jílové u Prahy, Czech Republic &