Satellite
altimetry
does NOT
accurately
measure
sea level rise
over time.
The satellite
"measurements"
show about
1.5x faster
sea level rise
than the best
tide gauges
( "dGPS" ),
where vertical
land motion
is corrected
with satellite
differential GPS.
There is a rise of
+3.4mm per year
with satellite altimetry,
versus +2.2mm per year
for dGPS tide gauges.
GPS measurements
have been around
less than 20 years,
but many tide gauges
have been working
for 100 years or more.
Satellite altimetry
uses radar
signal returns,
reflected off
a wavy ocean surface,
to estimate sea level
from the timing
of the signal,
from generation
to receipt.
This is similar to
a range estimating
radar systems
used for military
and commercial
aviation.
Military cruise missiles
need ranges in meters.
Commercial aviation
aircraft avoidance
concerns kilometers
between planes.
But sea level changes
are measured in
tiny millimeters
per year !
The Jason3 satellite
was launched
into polar orbit
on 1/17/2016.
The Jason3
product handbook
version 1.5,
was issued 9/17/18.
Jason 3 satellite data
overlap Jason2
satellite data,
and shows
significantly less
sea level rise
in the overlap period.
NASA's Jason3
‘product’ manual
claims a precision of
3.3 centimeters
( Sea Level Rise RMS pixel precision ).
No statistics can reduce
a minimum repeatable
precision error of >3 cm,
to the ‘average accuracy’
of 0.1 mm that NASA claims
( the .Jason3 product manual
§1.4.4 says all distance units
are reported in units of 1/10 millimeter ) !
NASA's Jason3 information
say it's ‘grouping’ precision
is 3.3 cm, which is
deceitfully reported
as 0.1mm.
Claiming
to measure
something
to 0.1mm,
using a tool
that has 3.3 cm
resolution,
is an exercise
in magic
( junk science ).
Measurements
with a low degree
of precision
can not be
miraculously
transformed
into a
high resolution,
high precision
number !
Ocean seawater is NOT level
because of a lumpy
planetary gravity field.
Here they are
measuring sea level,
at a variety of places,
at different times,
and in different conditions.
The satellite orbits precess,
so each revolution
sees a different view.
This is NOT
multiple measurements,
of the same thing,
at the same time,
which could improve
measurement accuracy.
Every measurement
is at a different location,
and by the time
a second measurement
is made at the same location,
the tide has changed.
The uncertainty
of multiple measurements,
of multiple things,
at multiple times,
can not be “averaged out”.
It remains in the final product.
Radar altimetry results
disagree with
other available data.
And the
claimed accuracy
is not credible.
Of course accuracy
and precision
don’t mean much
when the
mainstream media
publish so many
fairy tales about
a multi-meter
sea level rise
by 2100, with
artist’s renditions
of flooded
city streets
... fairy tales
which are
never challenged.
Arguing between
2mm or 3 mm per year
of sea level rise,
may be pointless
when
Scientific American,
National Geographic,
and various newspapers,
print fictional stories,
telling their readers
to expect ten times
that amount
of sea level rise,
in fairy tales
which are
never challenged.
Maldives Islands,
that were going to
disappear under
the rising waters
years ago,
are now home
to dozens of new
oceanfront resorts.
And the “rich green
leftist intelligentsia”
are still buying
oceanfront property
all over the world.
The satellite-measured
sea level rise rate
is 1.5x faster
than what
dGPS corrected
tide gauges report.
There is no logical reason
to use satellite altimetry
to measure tiny changes
in sea level.
But satellites ARE used,
because they show
significantly faster
sea level rise
than the best tide gauges.
In modern climate
junk science, whatever
measurement methodology
shows the most warming,
or the fastest sea level rise,
is used, and all other
measurement methodologies
are ignored, or slandered.
That's climate junk science,
not real climate science !