1. biomass TO OBSERVE FOREST BIOMASS
FOR A BETTER UNDERSTANDING OF THE CARBON CYCLE

2. The global carbon cycle

4. BIOMASS objectives and purpose
Objective of BIOMASS mission: to make accurate, frequent and global measurements of the distribution of forest biomass and its changes scales comparable with forest changes, and hence unprecedented information on status and dynamics of the Earth’s forests.
Crucial for:
Quantifying land use change (emissions & uptake)
Scientific support for international treaties
Landscape scale carbon dynamics and prediction
Initialising and testing the land element of ESMs
Forest ecosystem services & biodiversity

5. How well is biomass known?
Model
Brown
Potter
Model + Satellite
Interpolation44
Olson
Defries
Brown and Lugo
Fearnside
Interpolation
Carbon (tC/ha)
<= 100
226+
39 < Total biomass < 93 GtC
Malhi: old growth only based on 227 plots
Saatchi: 86 GtC +- 20%
Spatial patterns completely different.
Implications of this uncertainty shown on next slide
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EO used to help in LC (and in SS for structural variables, such as gap fraction)
44 sites used to extrapolate to 5 km
B&L: 1000s of plots, 1 km map; 63 GtC
F: same db, different conversions: 93 GtC
B: rule-based model, 5 km, calibrated at 44 sites
O: Pre-ag veg, air survey, plots, 1 degree
DF: % tree cover from AVHRR mixture model calibrated by Landsat MSS, 1km, biomass calibrated at 44 sites
P: CASA, driven by NDVI (for NPP) steady state, 1 degree
Land cover map
Estimates of total biomass vary from 39 to 93 GtC

6. Tropical forest aboveground biomass maps
Two recent maps of Amazonian biomass – radically different

7. Relation radar backscatter signal-above ground biomass at L, P, VHF bands
Landes forest, France
L-band SAR: RAMSES
P-band SAR: AirSAR
VHF SAR: Carabas

8. The sensitivity of P-band radar to biomass

9. Observation concept – P-band satellite radar
Calibration, Ionospheric correction
Orbit cycle n
Orbit cycle n+1
Polarimetric Interferometric
Phase HH HV VV
Phase
Polarimetric radar intensity
Retrieval algorithm
Geophysical products
The need to map biomass drives us immediately towards radar.
Optical sensors see biochemistry, radar sensitive to structure.
What sort of radar?
Polarimetry (figs on R)
Repeat pass for interferometry
Both critical as we can see
Forest biomass
Forest height
Forest biomass change
Forest disturbance

10. P-band forest height retrieval – tropical forest
Mawas, Indonesia 50 40 30 20 10 0m
e.g. of P band height in tropics
Also, I should remark that another beautiful complement of the height and intensity measurements is that the height measurements get more accurate for higher biomass, compensating for the reduced sensitivity of intensity methodss.

11. Tomography

12. Forest biomass retrieval at P-band
150
Les Landes
Estimated biomass (t/ha)
RMSE = 9.46 t/ha
150
In situ biomass (t/ha)
Biomass (t/ha)
`300
Inverting general P-HV curve
Note different ranges of biomass.
Point out value in last plot
Now we are going to add extra information
Estimated biomass (t/ha)
RMSE = 47.2 t/ha
`300
In situ biomass (t/ha)
Remningstorp

13. Improving biomass retrieval using polarisation & height
Biomass (t/ha)
Polarised intensities only
Intensity
retrieval
RMSE= 35.6 t/ha
Intensity + height
Height (m) 40 30 20 10 0m
Wher did we get height from?
One of the beautiful features of the radar system is that it allows an independent measure of height, using interferometry, as I’ll now explain
Height
retrieval
RMSE= 16.3 t/ha

16. Current status
Report for Selection submitted, exception for performance chapter
Ministerial conference towards the end of 2012
If (2) goes well, Consultation Meeting early 2013, selection within a couple of weeks
If (2) goes badly ....