Re: [ferret_users] How expand a data into spherical harmonic coefficients

To: Manche Shivashankar <mancheshivashankar@xxxxxxxxx>

Subject: Re: [ferret_users] How expand a data into spherical harmonic coefficients

From: Ryo Furue <furue@xxxxxxxxxx>

Date: Wed, 21 Dec 2016 00:56:58 +0900

Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=noaa-gov.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:x-original-sender:x-original-authentication-results:precedence :mailing-list:list-id:list-post:list-help:list-archive :list-unsubscribe; bh=HZAUgX2ngVW/7rYqVMJBLta1l3chNWwIAB4ODF3PHPY=; b=ob0ZxJ7dmSVzmPqruXe119227RK9jrKOUXbuznCaRgONnRX77pMEyqYKuDjInXdJBD hcBm0wmuQnh6oFt8m3orkxRNSCiDXX9KiaHv6/j2c7v95yyHo3DG5L6jmpMMINfUrrRN kCeiTs4A4qbvaX+UQtzCK0mL467BxSrke2AOg187FX8QuFXBss/TTLHbTG226BpZfDgJ FxR58rrwhUUK2RLHKaAtjGTG5PHQqafglAseB+Q8AhWjr9D0GgS1M0wueOPAdkYN27Pa E13za+1eBDxzgXZjaz2GhpwNhgP9Kxu+XNMZuQ3x9nsFrlAoRAQltIMIbr6e31O3dh/g XinA==

In-reply-to: <CAC0O64FyyTeOrhYGGeSjdcN+ZiB3d7OeuEAaS6V6wfvrueY=Gw@mail.gmail.com>

List-archive: <https://groups.google.com/a/noaa.gov/group/ferret_users/>

List-help: <https://support.google.com/a/noaa.gov/bin/topic.py?topic=25838>, <mailto:ferret_users+help@noaa.gov>

List-id: <ferret_users.noaa.gov>

List-post: <https://groups.google.com/a/noaa.gov/group/ferret_users/post>, <mailto:ferret_users@noaa.gov>

List-unsubscribe: <mailto:googlegroups-manage+809428289204+unsubscribe@googlegroups.com>, <https://groups.google.com/a/noaa.gov/group/ferret_users/subscribe>

Mailing-list: list ferret_users@xxxxxxxx; contact ferret_users+owners@xxxxxxxx

References: <CAC0O64FyyTeOrhYGGeSjdcN+ZiB3d7OeuEAaS6V6wfvrueY=Gw@mail.gmail.com>

Sender: owner-ferret_users@xxxxxxxx

Hi Manche Shivashankar,

On Tue, Dec 20, 2016 at 4:37 AM, Manche Shivashankar <mancheshivashankar@xxxxxxxxx> wrote:

I have grace data prepared based on spherical harmonics, now I want to compare this data with sea level data. Sea level data to be consistent with grace data in spatial domain I want to convert/expand my sea level data into spherical harmonic coefficients.

I don't have a more useful suggestion than that you can use a spherical-harmonics library out there; but I'm curious. What would you do with land, where sea level data doesn't exist? Whatever you do with the land, you would get spurious harmonics due to the landmasses, I would think. Why don't you convert the GRACE data into the physical space, instead of converting sea level into the spectral space?

Regards,

Ryo