ao-postflight: compute barometric alt for each GPS position

Print that to the --gps file, and use that in the --kml file for the
altitude. Gives a very different picture of our flight tracks,
presumably far more accurate (at least in altitude).

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/ao-tools/ao-postflight/ao-postflight.c b/ao-tools/ao-postflight/ao-postflight.c
index caa7fb74e755641b3a56c06ca0329532c05a61f9..51bcd6e3f53932755ea7e46e8ea716a2033d84a2 100644 (file)
--- a/ao-tools/ao-postflight/ao-postflight.c
+++ b/ao-tools/ao-postflight/ao-postflight.c
@@ -351,10 +351,21 @@ analyse_flight(struct cc_flightraw *f, FILE *summary_file, FILE *detail_file,
                                time, pres, accel);
                }
        }
-       if (gps_file) {
-               int     j = 0;
-               fprintf(gps_file, "%9s %12s %12s %12s\n",
-                       "time", "lat", "lon", "alt");
+       if (gps_file || kml_file) {
+               int     j = 0, baro_pos;
+               double  baro_offset;
+               double  baro = 0.0;
+
+               if (gps_file)
+                       fprintf(gps_file, "%9s %12s %12s %9s %8s %5s\n",
+                               "time", "lat", "lon", "alt", "baro", "nsat");
+               if (kml_file)
+                       fprintf(kml_file, "%s", kml_header);
+               if (f->gps.num)
+                       baro_offset = f->gps.data[0].alt;
+               else
+                       baro_offset = 0;
+               baro_pos = 0;
                for (i = 0; i < f->gps.num; i++) {
                        int     nsat = 0;
                        int     k;
@@ -364,52 +375,56 @@ analyse_flight(struct cc_flightraw *f, FILE *summary_file, FILE *detail_file,
                                        break;
                                j++;
                        }
-                       fprintf(gps_file, "%12.7f %12.7f %12.7f %12.7f",
-                               (f->gps.data[i].time - boost_start) / 100.0,
-                               f->gps.data[i].lat,
-                               f->gps.data[i].lon,
-                               f->gps.data[i].alt);
+                       if (cooked) {
+                               while (baro_pos < cooked->pres_pos.num) {
+                                       double  baro_time = cooked->accel_accel.start + baro_pos * cooked->accel_accel.step;
+                                       if (baro_time >= f->gps.data[i].time)
+                                               break;
+                                       baro_pos++;
+                               }
+                               if (baro_pos < cooked->pres_pos.num)
+                                       baro = cooked->pres_pos.data[baro_pos];
+                       }
+                       if (gps_file)
+                               fprintf(gps_file, "%12.7f %12.7f %12.7f %7.1f %7.1f",
+                                       (f->gps.data[i].time - boost_start) / 100.0,
+                                       f->gps.data[i].lat,
+                                       f->gps.data[i].lon,
+                                       f->gps.data[i].alt,
+                                       baro + baro_offset);
+                       if (kml_file) {
+                               fprintf(kml_file, "%12.7f, %12.7f, %12.7f <!-- alt %12.7f time %12.7f sats %d -->",
+                                       f->gps.data[i].lon,
+                                       f->gps.data[i].lat,
+                                       baro + baro_offset,
+                                       f->gps.data[i].alt,
+                                       (f->gps.data[i].time - boost_start) / 100.0,
+                                       nsat);
+                               if (i < f->gps.num - 1)
+                                       fprintf(kml_file, ",\n");
+                               else
+                                       fprintf(kml_file, "\n");
+                       }
+
                        nsat = 0;
                        for (k = 0; k < f->gps.sats[j].nsat; k++) {
-                               fprintf (gps_file, " %12.7f", (double) f->gps.sats[j].sat[k].c_n);
                                if (f->gps.sats[j].sat[k].svid != 0)
                                        nsat++;
                        }
-                       fprintf(gps_file, " %d\n", nsat);
-               }
-       }
-       if (kml_file) {
-               int     j = 0;
-
-               fprintf(kml_file, "%s", kml_header);
-               for (i = 0; i < f->gps.num; i++) {
-                       int     nsat = 0;
-                       int     k;
-                       while (j < f->gps.numsats - 1) {
-                               if (f->gps.sats[j].sat[0].time <= f->gps.data[i].time &&
-                                   f->gps.data[i].time < f->gps.sats[j+1].sat[0].time)
-                                       break;
-                               j++;
+                       if (gps_file) {
+                               fprintf(gps_file, " %4d", nsat);
+                               for (k = 0; k < f->gps.sats[j].nsat; k++) {
+                                       if (f->gps.sats[j].sat[k].svid != 0) {
+                                               fprintf (gps_file, " %3d(%4.1f)",
+                                                        f->gps.sats[j].sat[k].svid,
+                                                        (double) f->gps.sats[j].sat[k].c_n);
+                                       }
+                               }
+                               fprintf(gps_file, "\n");
                        }
-                       nsat = 0;
-                       if (j < f->gps.numsats) {
-                               for (k = 0; k < f->gps.sats[j].nsat; k++)
-                                       if (f->gps.sats[j].sat[k].svid != 0)
-                                               nsat++;
-                       }
-
-                       fprintf(kml_file, "%12.7f, %12.7f, %12.7f <!-- time %12.7f sats %d -->",
-                               f->gps.data[i].lon,
-                               f->gps.data[i].lat,
-                               f->gps.data[i].alt,
-                               (f->gps.data[i].time - boost_start) / 100.0,
-                               nsat);
-                       if (i < f->gps.num - 1)
-                               fprintf(kml_file, ",\n");
-                       else
-                               fprintf(kml_file, "\n");
                }
-               fprintf(kml_file, "%s", kml_footer);
+               if (kml_file)
+                       fprintf(kml_file, "%s", kml_footer);
        }
        if (cooked && plot_name) {
                struct cc_perioddata    *speed;