bigmap

(Compiled by TC)

Description

This procedure creates a large topographical/albedo map with the same file structure as a maplet. The location of the map center is specified by one of three choices:

p: pixel/line location in a picture
l: latitude and west longitude
m: pixel line location in a bigmap or maplet.

A second set of inputs contains the bigmap scale in km/px, the half-size (qsz), an integer random seed, and a maximum maplet scale in case lower resolution maplets are to be excluded.

The program first determines the body-fixed vector to the map center and the approximate surface normal vector (Uz). It then projects the shape model onto this surface and determines a second approximation of Uz by fitting a plane to the heights. It repeats this process one more time. The new map coordinate frame is then oriented so that East is to the right.

The maplets to be used in the construction are taken from the first of the files BIGMAP.IN, LMRKLISTR.TXT or LMRKLIST.TXT found to exist. However, if LMKLX=.TRUE. in the INIT_LITHOS.TXT file, the program will read LMRKLISTX.TXT. If there are a great many maplets, the latter choice will speed up the procedure by determining whether a maplet needs to be used without having to open its .LMK file.

The bigmap reference plane has (2*qsz+1)^2 points at locations:

p(i,j) = V + j*Ux +i*Uy   (i,j = -qsz,qsz)

A line from each of these points in the normal (Uz) direction will pierce a number of maplets. For each i,j we keep track of the weighted accumulation of the heights to the piercing points, the squares of those heights, and the slopes and albedos of the maplets at the piercing points.

Once these arrays are filled, the average heights and albedos at each point of the reference plane are computed, as well as the standard deviation of the heights. This provides a convenient measure of the height uncertainty at each point, and displaying SIGMAS.pgm provides a quick means of identifying possible problem areas.

Input stdin

A long set of commands are sent into this program that are usually contained within a file
$/!\$ Longitude is in west longitude (meaning that you need a negative to match what is used in spheremapB.e
example:

- Location of bigmap depends on server, try /usr/local/bin as default

 ~/bin/bigmap < ZN0208.IN

Input file

The format is normally something like this.

l   (select location, 1 is lat/lon)
    20    -40    (latitude, west longitude)
   0.06250       500   1.23400   1000  (scale, qsz (number of pixels), seed, max maplet res) 
ZN0208           (filename)
1                (end or integrate, 1 is integrate)
.005             (input fraction)
.025             (input weight)
1                (end, continue, or change weight, 1 is continue integrating)
0                (end, continue, or change weight, 0 is end iteration)
0                (no, square, or round template, 0 is No Template)
1                (end, continue, or change weight, 1 is continue integrating)
1                (end, continue, or change weight, 1 is continue integrating)
1                (end, continue, or change weight, 1 is continue integrating)
1                (end, continue, or change weight, 1 is continue integrating)
1                (end, continue, or change weight, 1 is continue integrating)
1                (end, continue, or change weight, 1 is continue integrating)
0                (end, continue, or change weight, 0 is end iteration)
0                (no, square, or round template, 0 is No Template)

Requires

LMKFILES/ - directory of .LMK files for each maplet
LMRKLIST.TXT - Required. List of landmarks
MAPFILES/ - directory of .MAP files
SHAPEFILES/ - directory of built shapes
BIGFILES/ - directory of .LMK files for each of the required bigmaps - directory must be created, but changes are made within.
SUMFILES/ - info about the maplets
Many files must be unique. All directories can be linked to a master.

Optional

BIGMAP.IN - a list of landmarks that you want to use for bigmap. It allows you to reduce the number of files and avoid low resolution images.
LMRKLIST.TXT - Same as above, but only used if BIGMAP.IN is missing (used for historical purposes)
If there are neither of these files, then it will build the list of files that are included in the coverage

Output

INSIDE.TXT - The maplets that fall completely within the planned bigmap. Created by bigmap
USED_MAPS.TXT - All the maps used to create the bigmap.
BIGLIST.TXT - list of needed mapfiles (bigmaps) used to construct the working bigmap
USED_PICS.TXT - list of all pictures used in the creation of most recent bigmap
bigmap with the name based on the input (e.g. ZN0208.IN).
slope.pgm image, that shows the slope in both in horizontal and vertical.
SIGMAS.TXT - Each time BIGMAP is run, it will add a line to this file showing the current sigma values
SIGMAS.pgm - It graphically shows the highest level of error (sigma) is for maplets.