Replace EGM2008 solution

[remkos]

In March 2025, JPL reported an error in the EGM2008 grids used in all operational missions (Jason-3, SARAL/AltiKa, CryoSat-2, Sentinel-3, Sentinel-6).

Unfortunately, the same error slipped into RADS as well.

Thus the field geoid_egm2008 is to be replaced on all missions:

• gs
• g1
• e1
• e2
• n1
• tx
• pn
• j1
• j2
• j3
• sa
• sw
• 3a
• 3b
• 6a.lr
• 6a.hr
• c2