Observatories

[StephenG1CMZ]

This program attempts to parse the observatories file from the Minor Planets Centre and map their locations.

But I'm not convinced by the map.

The map was done quickly, so I wouldn't be surprised to find it upside down (why is 0 at the top of computer screens???).

One complication with the original data is that latitudes are given as a composite value (lat*elevation), but I assume that will be a good enough approximation.

Eventually, I intend to incorporate this into my GEODATA program and/or an astronomical app.

If anyone who knows where the observatories are can indicate whether that map looks reasonable it would be appreciated - I was assuming it would look more like a world map...maybe my expectations were wrong, or do I have a bug in my handling of the coordinates.

[StephenG1CMZ]

Version 0.001

Code:



 // OBSERVATORIES V0.001 2017 StephenG1CMZ

 LOCAL LF:=CHAR(10);
 LOCAL FS:=Notes("OBSERVATORIES.MPC");
 
 //CUSTOMISE
 LOCAL SHOWPROGRESS:=0;

 LOCAL LINES;
 LOCAL ZNAN;
 LOCAL OBSCODE,OBSFULLNAME;
 LOCAL OBSNUMI;
 LOCAL OBSCODES:={},OBSFULLNAMES:={};
 LOCAL OBSLNGS:={};
 LOCAL OBSLATS:={};

 LOCAL LINESPOS:={};
 
 LOCAL NUM1,NUM2,NUM3,NUM3SIGN;
 LOCAL LNGNUM;
 LOCAL LATCOS,LATSIN,LAT;

 IZWHITE(ST)
 BEGIN
  LOCAL WHITESP:=" ";
  LOCAL POS:=1;
  IF DIM(ST)==0 THEN
  MSGBOX("EMPTY");
   RETURN 1;
  END;

  WHILE INSTRING(WHITESP,MID(ST,POS,1)) AND POS≤DIM(ST)  DO
   POS:=POS+1;
  END;
  RETURN (POS>DIM(ST)); //1=WHITESPACE ELSE 0 
 END;

 PARSE_OBS(ALINE)
 BEGIN
  OBSCODE:=MID(ALINE,1,4);
  IF SHOWPROGRESS THEN
   DRAWMENU(OBSCODE);
  END;
  //IF MID(OBSCODE,4)==" " THEN
  //ELSE
  // MSGBOX("BAD OBSCODE "+ASC(MID(OBSCODE,4)));
  // RECT_P();
  // END;
  //PRINT(ALINE);
   
  IF OBSCODE=="Code" THEN
   //HEADR LINE
  ELSE
   ZNAN:=0;
   NUM1:=(MID(ALINE,4,10));
   IF IZWHITE(NUM1) THEN
    //PRINT(".");
    NUM1:="0";ZNAN:=1; //NAN
    //DEBUG;
   END;
   LNGNUM:=EXPR(NUM1);
   IF ZNAN THEN
    LAT:=0;
   ELSE
    NUM2:=MID(ALINE,4+10,8);
    NUM3SIGN:=MID(ALINE,4+10+8,1);
    NUM3:=MID(ALINE,4+10+8+1,8);
    //LATCOS:=ACOS(EXPR(NUM2));
    LATCOS:=EXPR(NUM2);
    //PRINT(LATCOS);DEBUG;
    //PRINT(NUM3);
    LATSIN:=(180/π)*ASIN(EXPR(NUM3));
    //LAT:=(LATCOS+LATSIN)/2;
   END;
   IF NUM3SIGN=="-" THEN
    LATSIN:=−LATSIN;
   END;
   //
   LAT:=LATSIN;
   OBSFULLNAME:=MID(ALINE,32-1);
   //PRINT(MID(ALINE,1,4)+" "+OBSNAME);
   OBSCODES(OBSNUMI):=OBSCODE;
   OBSFULLNAMES(OBSNUMI):=OBSFULLNAME;
   OBSLNGS(OBSNUMI):=LNGNUM;
   OBSLATS(OBSNUMI):=LAT;
   IF OBSCODE=="007 " AND 0 THEN
    MSGBOX("48-50= "+→HMS(LAT));
   END;
   OBSNUMI:=OBSNUMI+1;
  END;
 END;

 EXPORT READ_ALL_OBS(ST)
 BEGIN
  LOCAL LFOFFSET,CH;
  LOCAL FRM,TOO;
  LOCAL TMP;
  LINESPOS:={0};
  LINES:=1; OBSNUMI:=1;
  IF SHOWPROGRESS OR 1 THEN
   DRAWMENU("Loading");
  END;
  REPEAT
   LFOFFSET:=INSTRING(MID(ST,LINESPOS(LINES)+1),LF);
   IF LFOFFSET THEN
    LINESPOS(LINES+1):=LINESPOS(LINES)+LFOFFSET;
    CH:= MID(ST,LINESPOS(LINES+1),1);
    IF CH==LF THEN
    ELSE
      MSGBOX("BAD LF"+CH);
    END;
    FRM:=LINESPOS(LINES)+1;
    TOO:=LINESPOS(LINES+1);
    PARSE_OBS(MID(ST,FRM,TOO-FRM));
    IF MID(ST,FRM,1)=="Z" AND 0 THEN
     PRINT("LINE"+LINES+"FRM"+FRM+"TO"+TOO);
     PRINT("CODE: "+MID(ST,FRM,4));
     PRINT(MID(ST,FRM,TOO-FRM));
    END;
    LINES:=LINES+1;
    //WAIT;
   END;
  UNTIL LFOFFSET==0;
  //DEBUG;
  //FINAL LINE IF LAST LF MISSING
  FRM:=LINESPOS(LINES)+1;
  TOO:=SIZE(ST)-FRM;
  PARSE_OBS(MID(ST,FRM,TOO));
 //PRINT("SIZE "+SIZE(ST));
  //PRINT("Lines: "+LINES);
 END;

 QUICKPLOT()
 BEGIN
  LOCAL II,XX,YY;
  RECT_P();
  //(NEEDS ":0-360=-180,180 ETC
  //MSGBOX(SIZE(OBSFULLNAMES));
  FOR II FROM 1  TO SIZE(OBSFULLNAMES) DO
   XX:=OBSLNGS(II);
   XX:=IFTE(XX>180,−(360-XX),XX);
   XX:=(320/360)*OBSLNGS(II);
   YY:=(240/180)*(OBSLATS(II)+90);
   RECT_P(XX,YY,XX,YY,RGB(255,0,0),RGB(99,99,99)); 
  END;
  DRAWMENU("DONE");
  
 END;

 VERY_INFO()
 BEGIN
  WAIT;
  PRINT("Found "+SIZE(OBSCODES)+" Observatories");
 END;

 PROGRAMR_INFO()
 //USE FOR DISPLAY SIZING
 BEGIN
  LOCAL II,ML,LONGNAME;
  PRINT("Longitudes:"+MIN(OBSLNGS)+".."+MAX(OBSLNGS));
  PRINT("Latitudes: "+MIN(OBSLATS)+".."+MAX(OBSLATS));
  ML:=0;
  FOR II FROM 1 TO SIZE(OBSFULLNAMES) DO
   IF DIM(OBSFULLNAMES(II))>ML THEN
    ML:=DIM(OBSFULLNAMES(II));
    LONGNAME:=OBSFULLNAMES(II);
   END;
  END;
  PRINT("LONGFULLNAME "+ML);
  PRINT(LONGNAME);
  WAIT;
  TEXTOUT_P(LONGNAME,0,200,3);//3 IS LARGEST FONT TO FIT NAME ON 1 LINE
 END;

 EXPORT OBS()
 BEGIN
  LOCAL TBEG;
  PRINT();
  //MSGBOX(IZWHITE(" B   "));
  TBEG:=TICKS;
  READ_ALL_OBS(FS);
  TBEG:=TICKS-TBEG;
  PRINT((TBEG/1000)+" s");
  VERY_INFO();
  PROGRAMR_INFO();
  //MSGBOX("DONE");
  WAIT;
  QUICKPLOT();
  WAIT;
 END;