cik = Chisago, Isanti, Kanabec, Mille Lacs, Sherburne This one's messy, since only half the intended coverage was flown in 2002. The shapefile indexes described below have all undergone considerable processing to bring field names and types into alignment, import altitude values, etc. etc. The accompanying text files were the starting points. ======================================================================= 2002 cik_2002_idx represents all frames flown in 2002. (This is _not_ the same as the "ortho2002" index, which was a subset of cik_2002_idx.) Initially, no altitude data was obtained for these flights. grw_2002_with_z was obtained after-the-fact as a source of altitude data for the photos flown by GRW. That info was joined and transferred to cik_2002_idx. Altitude data for the 2002 photos flown by GLA(S) was provided in the form of glas_mndnr02_orig.txt. The textfile was processed into the mndnr02 shapefile and reprojected to UTM Zone 15. Since flightlines and exposure numbers did not match between mndnr02 and the "master" cik_idx shapefile (the textfile must contain GLAS' internal-use numbering, and not our split-by-county numbering), it was not possible to join tables in order to transfer the altitude data to cik_idx. Instead, a spatial join was used with the "nearest" option, all records with a "distance" field value < 2 feet were selected (533 records, appears should have been 534 - the number of records in mndrn02 - oh well), and the altitude values transferred on that basis. Don't know why there were distance values - should have been the exact same points - maybe precision differences in the lat/long, or some minor datum issue. Date and time stamps for the frames seemed to correlate correctly on the basis of the spatial join. The glas_mndnr02_orig.txt file contained a "bonus" field called "COG" (?), which appears to be flight direction. A new field named "ANGLE" was added to cik_idx, and this information was transferred to it via the spatial join described above. ======================================================================= 2003 cik_2003_idx is for the second half of the coverage, flown in 2003. This data included altitude values from the start. NOTE that when GLAS sent up the file with altitude values for 2002, they included one for the 2003 stuff as well (glas_mndnr03.txt - originally smick.txt). That file contains the same "COG" field that appears to give flight orientation for each frame. Converted to shapefile and reprojected to utm. However, there seem to be some "extra" points in the shapefile, so haven't tried to transfer that info over to cik_idx. Note that errors in chi line 5 were corrected in the merged 2002/2003 version of the index, but _not_ the cik_2003_idx shapefile. See below. ======================================================================= Merged cik_idx is a merge of the two years' worth of coverage. Note that flightline 15 in eastern Kanabec county, flown 2002 but never printed, has been removed from this shapefile. The FLY_HEIGHT field is (finally) populated for all frames, see notes above. The ANGLE field contains data appearing to be an indication of flight direction for some frames (those flown by GLA(S), where we needed to chase down altitude values and got this info to boot - originally a field labelled "COG"). 8/4/04 In the course of ortho work, it was discovered that the point for chi-05-021 was incorrect (an "extra" frame snapped as they picked up the flightline after looping around or something), and that all subsequent points and attributes were offset by one frame - that is, data given for chi-05-022 really belonged to chi-05-021, etc. down to the end of the line. Data for the final frame in the line, chi-05-037, was missing. This was corrected in the merged shapefile by deleting the point for chi-05-021, and re-attributing the rest of the points in the line to eliminate the offset described above (eg., chi-05-022 was changed to chi-05-021). A location was estimated for chi-05-037 based on correlating the image center with the DOQs, a new point was added there and attributes filled in. No lat/long values were estimated, but flying altitude was pegged at 8950 (close to the values of neighboring frames). The rest of the attributes for the frame are real. These corrections were then transferred to the indexes used in ortho work. The corrections have _not_ been back-transferred to the cik_2003_idx shapefile. ======================================================================= All of this will continue to live under a y2002 directory, since that's when it was originally scheduled.