Crozet

 

CROB 91301S001

CRPB 91301S002

CRQB 91301S003

 

DM#491 CRPB new station since 05-APR-2007

 

CRPB is not in ITRF2005

CRQB is not in ITRF2005. See DORISMail #0593

 

Preliminary computations:

 

Geodetic local tie is available in the DORISMail (from CROB to CRPB)

dE = dN = 0; dh = 0.150 m

Hence in XYZ = 0.064 0.081 -0.109

 

CROB in ITRF2005 is

 

CROB 2000.0 2719992.097 3463401.924 -4598608.144 -5.89 2.87 -2.67

 

Then, we derive

 

CRPB 2000.0 2719992.161 3463402.005 -4598608.253 -5.89 2.87 -2.67

 

The position, derived from DORIS solution (tf_070515a), using CROB velocity is

 

2000.0 CRPB 2719992.1578 3463402.0081 -4598608.2578 -5.89 2.87 -2.67

statistics CRPB XYZ 0.0148 0.0144 0.0122 2

 

There is just 2 weeks of data, so we need to verify this point later on. Current difference is quite good for these 2 weeks: in XYZ (mm): -3 3 -5

 

Using more DORIS data (ign07d02), we obtain :

 

2000.0 CRPB 2719992.1708 3463402.0079 -4598608.2457 -5.89 2.87 -2.67

statistics CRPB XYZ 0.0023 0.0023 0.0018 42

 

so this is in good agreement with the proposed model

 

For CRQB, using latest available DORIS results (ignwd08) provides

 

2000.0 CRQB 2719992.2648 3463402.1322 -4598608.4004 -5.89 2.87 -2.67

statistics CRQB XYZ 0.0027 0.0021 0.0022 31

 

While coordinates in the DORISMail #593 are

 

X = 2719992.247 m Y = 3463402.117 m Z = -4598608.399 m

(sigma: 3 cm)

 

VX = -0.0059 m/y VY = 0.0029 m/y VZ = -0.0027 m/y

SigVX = 0.0055 m/y SigVY = 0.0049 m/y SigVZ = 0.0041 m/y

 

This provides a good agreement

 

Recommendation:

 

Use geodetic local and verify with recent DORIS data (using CROB velocity)

 

For CRQB use DORIS-derived results

 

2000.0 CRQB 2719992.2648 3463402.1322 -4598608.4004 -5.89 2.87 -2.67