SUBROUTINE ERRMPD(MPAZ,MPDIST,VCINIT,VCDIR)                               
C                                                                               
C        THIS SUBROUTINE WILL COMPUTE THE VARIANCE COVARIANCE MATRIX OF THE     
C      X,Y COORDINATES OF POINTS 1 AND 2 FROM THE DIRECT SOLUTION OF GEODETIC   
C      POSITIONING ON A MAPPING PLANE.                                          
C                                                                               
C        INPUT:                                                                 
C                                                                               
C              MPAZ - AZIMUTH ON THE MAPPING PLANE (IN RADIANS).                
C              MPDIST - DISTANCE FROM POINT 1 TO 2 ON THE MAPPING PLANE.        
C              VCINIT - VARIANCE COVARIANCE MATRIX OF POINT 1 AND THE           
C                       OBSERVATIONS.                                           
C                                                                               
C        OUTPUT:                                                                
C                                                                               
C              VCDIR - VARIANCE COVARIANCE MATRIX OF THE X,Y COORDINATES OF     
C                      POINTS 1 AND 2.                                          
C                                                                               
C                                           WRITTEN BY G.BOWIE, DEC. 1977.      
C                                                                               
      IMPLICIT REAL*8 (A-Z)                                                     
      REAL*8 B(4,4)/16*0.D0/,BVC(4,4),BT(4,4),VCDIR(4,4),VCINIT(4,4)            
      B(1,1)=1.D0                                                               
      B(2,2)=1.D0                                                               
      B(3,1)=1.D0                                                               
      B(3,3)=DSIN(MPAZ)                                                         
      B(3,4)=DCOS(MPAZ)*MPDIST                                                  
      B(4,2)=1.D0                                                               
      B(4,3)=DCOS(MPAZ)                                                         
      B(4,4)=-DSIN(MPAZ)*MPDIST                                                 
      CALL TRNSD(BT,4,B,4,4,4)                                                  
      CALL MMULD(BVC,4,B,4,VCINIT,4,4,4,4)                                      
      CALL MMULD(VCDIR,4,BVC,4,BT,4,4,4,4)                                      
      WRITE(6,100)                                                              
  100 FORMAT('     DESIGN MATRIX-DIRECT CASE')                                  
      CALL MOUTD(B,4,4,4)                                                       
      WRITE(6,101)                                                              
  101 FORMAT('     VC MATRIX-INITIAL')                                          
      CALL MOUTD(VCINIT,4,4,4)                                                  
      WRITE(6,102)                                                              
  102 FORMAT('     VC MATRIX-DIRECT CASE')                                      
      CALL MOUTD(VCDIR,4,4,4)                                                   
      RETURN                                                                    
      END